Citrix Netscaler – Loadbalancing Exchange 2013/2016 (Walkthrough Guide)

If you get the task to load balance Exchange with NetScaler you will find a lot of whitepapers from Citrix with missing information and false configuration recommendations. I was bumping my head against the wall until I got a running configuration with all desired features. Here is the complete walkthrough guide to setup your Exchange environment with a single public ip address. Additional features like AAA, Front End Optimization  and Integrated Caching will depend on your current NetScaler licence.

Change Log
2018-05-23
– Added 401 Based Authentication for MAPI, RPC, OAB, EWS
– Added Group Filtering for OWA, Outlook Anywhere and ActiveSync
2018-05-16
– Changed Persistence for the RPC/MAPI LB vServer from RULE to SOURCEIP
– Increased timeout from 240 to 30 minutes (RPC/MAPI)

Table of contents
1. Feature Matrix
2. Network Topology
3. Requirements
3.1 Firewall Rules
4. Configuration
4.1 Features
4.2 Server
4.3 Monitors
4.4 Service Groups
4.5 Load Balancer
4.6 Content Switch
4.7 AAA (Enterprise)
4.7.1 Authentication Policies
4.7.2 SSO Traffic Policies
4.7.3 Group Filtering
4.8 Front End Optimization (Enterprise)
4.9 Integrated Caching (Platinum)

1. Feature Matrix

Licence

Load Balancing

Content Switching

Responder

AAA

Front End Optimization

Integrated Caching

Standard

x

x

x

Enterprise

x

x

x

x

x

Platinum

x

x

x

x

x

x

2. Network Topology

diagram

3. Requirements

  • One public ip address
  • Two private IP addresses (Content Switch and Load Balancer)
  • Working DNS/NTP on NetScaler
  • Wildcard SSL certificate

3.1 Firewall Rules

From

To

Port

Description

SNIP

DNS Server

UDP/TCP 53

DNS

SNIP

NTP Server

UDP 123

NTP

SNIP

Domain Controller

TCP 389

LDAP

SNIP

Domain Controller

TCP 636

LDAPS

NSIP

Exchange Server

TCP 25, 465, 587

SMTP Monitor

SNIP

Exchange Server

TCP 25, 465, 587

SMTP

SNIP

Exchange Server

TCP 143, 993

IMAP

SNIP

Exchange Server

HTTPS – 443

OWA, AutoDiscover, ActiveSync, MAPI, etc.

Internet

SMTP LB IP

TCP 25, 465, 587

SMTP

Internet

IMAP LB IP

TCP 143, 993

IMAP

Internet

Content Switch VIP

HTTP – 80

Web Traffic

Internet

Content Switch VIP

HTTPS – 443

Web Traffic

If you dont load balance DNS/LDAPS/NTP the traffic will flow from the NSIP. In my setup the servers are load balanced –> The SNIP is communicating with the backend servers.

4. Configuration

4.1 Features

#Features
enable ns feature CS,RESPONDER,LB,SSL

4.2 Server

#Create serves
#Replace FQDN and ip address regarding  your environment
add server EX01.lab.local 192.168.2.102
add server EX02.lab.local 192.168.2.103

4.3 Monitors

Name

Type

Standard Parameter

Send String

mon_smtp

SMTP

mon_owa

HTTP-ECV

Secure

“GET /owa/healthcheck.htm”

mon_activesync

HTTP-ECV

Secure

“GET /Microsoft-Server-ActiveSync/healthcheck.htm”

mon_rpc

HTTP-ECV

Secure

“GET /rpc/healthcheck.htm”

mon_ews

HTTP-ECV

Secure

“GET /ews/healthcheck.htm”

mon_autodiscover

HTTP-ECV

Secure

“GET /Autodiscover/healthcheck.htm”

mon_mapi

HTTP-ECV

Secure

“GET /mapi/healthcheck.htm”

mon_ecp

HTTP-ECV

Secure

“GET /ecp/healthcheck.htm”

#Create monitors
add lb monitor mon_smtp SMTP
add lb monitor mon_owa HTTP-ECV -send "GET /owa/healthcheck.htm" recv 200 -LRTM DISABLED -secure YES
add lb monitor mon_activesync HTTP-ECV -send "GET /Microsoft-Server-ActiveSync/healthcheck.htm" recv 200 -LRTM DISABLED -secure YES
add lb monitor mon_rpc HTTP-ECV -send "GET /rpc/healthcheck.htm" recv 200 -LRTM DISABLED -secure YES
add lb monitor mon_ews HTTP-ECV -send "GET /ews/healthcheck.htm" recv 200 -LRTM DISABLED -secure YES
add lb monitor mon_autodiscover HTTP-ECV -send "GET /Autodiscover/healthcheck.htm" recv 200 -LRTM DISABLED -secure YES
add lb monitor mon_oab HTTP-ECV -send "GET /oab/healthcheck.htm" recv 200 -LRTM DISABLED -secure YES
add lb monitor mon_mapi HTTP-ECV -send "GET /mapi/healthcheck.htm" recv 200 -LRTM DISABLED -secure YES
add lb monitor mon_ecp HTTP-ECV -send "GET /ecp/healthcheck.htm" recv 200 -LRTM DISABLED -secure YES

4.4 Service Groups

Name

Protocol

Monitor

svcgrp_ex2016_smtp_25

TCP

mon_smtp

svcgrp_ex2016_smtp_465

TCP

mon_smtp

svcgrp_ex2016_smtp_587

TCP

mon_smtp

svcgrp_ex2016_imap_143

TCP

TCP

svcgrp_ex2016_imap_993

TCP

TCP

svcgrp_ex2016_owa

SSL

mon_owa

svcgrp_ex2016_activesync

SSL

mon_activesync

svcgrp_ex2016_rpc

SSL

mon_rpc

svcgrp_ex2016_ews

SSL

mon_ews

svcgrp_ex2016_autodisover

SSL

mon_autodiscover

svcgrp_ex2016_oab

SSL

mon_oab

svcgrp_ex2016_mapi

SSL

mon_mapi

svcgrp_ex2016_epc

SSL

mon_epc

#Create Service Groups
add serviceGroup svcgrp_ex2016_smtp_25 TCP
add serviceGroup svcgrp_ex2016_smtp_465 TCP
add serviceGroup svcgrp_ex2016_smtp_587 TCP
add serviceGroup svcgrp_ex2016_imap_143 TCP
add serviceGroup svcgrp_ex2016_imap_993 TCP
add serviceGroup svcgrp_ex2016_owa SSL
add serviceGroup svcgrp_ex2016_activesync SSL
add serviceGroup svcgrp_ex2016_rpc SSL
add serviceGroup svcgrp_ex2016_ews SSL
add serviceGroup svcgrp_ex2016_autodisover SSL
add serviceGroup svcgrp_ex2016_oab SSL
add serviceGroup svcgrp_ex2016_mapi SSL
add serviceGroup svcgrp_ex2016_ecp SSL
#Bind Service Groups
#Replace FQDN and ip address regarding your environment
bind servicegroup svcgrp_ex2016_smtp_25 EX01.lab.local 25
bind servicegroup svcgrp_ex2016_smtp_25 EX02.lab.local 25
bind serviceGroup svcgrp_ex2016_smtp_25 -monitorName mon_smtp

bind servicegroup svcgrp_ex2016_smtp_465 EX01.lab.local 465
bind servicegroup svcgrp_ex2016_smtp_465  EX02.lab.local 465
bind serviceGroup svcgrp_ex2016_smtp_465 -monitorName mon_smtp

bind servicegroup svcgrp_ex2016_smtp_587 EX01.lab.local 587
bind servicegroup svcgrp_ex2016_smtp_587 EX02.lab.local 587
bind serviceGroup svcgrp_ex2016_smtp_587 -monitorName mon_smtp

bind servicegroup svcgrp_ex2016_imap_143 EX01.lab.local 143
bind servicegroup svcgrp_ex2016_imap_143 EX02.lab.local 143
bind serviceGroup svcgrp_ex2016_imap_143 -monitorName TCP

bind servicegroup svcgrp_ex2016_imap_993 EX01.lab.local 993
bind servicegroup svcgrp_ex2016_imap_993 EX02.lab.local 993
bind serviceGroup svcgrp_ex2016_imap_993 -monitorName TCP

bind servicegroup svcgrp_ex2016_owa EX01.lab.local 443
bind servicegroup svcgrp_ex2016_owa EX02.lab.local 443
bind serviceGroup svcgrp_ex2016_owa -monitorName mon_owa

bind servicegroup svcgrp_ex2016_activesync EX01.lab.local 443
bind servicegroup svcgrp_ex2016_activesync EX02.lab.local 443
bind servicegroup svcgrp_ex2016_activesync -monitorName mon_activesync

bind servicegroup svcgrp_ex2016_rpc EX01.lab.local 443
bind servicegroup svcgrp_ex2016_rpc EX02.lab.local 443
bind servicegroup svcgrp_ex2016_rpc -monitorName mon_rpc

bind servicegroup svcgrp_ex2016_ews EX01.lab.local 443
bind servicegroup svcgrp_ex2016_ews EX02.lab.local 443
bind servicegroup svcgrp_ex2016_ews -monitorName mon_ews

bind servicegroup svcgrp_ex2016_autodisover EX01.lab.local 443
bind servicegroup svcgrp_ex2016_autodisover EX02.lab.local 443
bind servicegroup svcgrp_ex2016_autodisover -monitorName mon_autodiscover

bind servicegroup svcgrp_ex2016_oab EX01.lab.local 443
bind servicegroup svcgrp_ex2016_oab EX02.lab.local 443
bind servicegroup svcgrp_ex2016_oab -monitorName mon_oab

bind servicegroup svcgrp_ex2016_mapi EX01.lab.local 443
bind servicegroup svcgrp_ex2016_mapi EX02.lab.local 443
bind servicegroup svcgrp_ex2016_mapi -monitorName mon_mapi

bind servicegroup svcgrp_ex2016_ecp EX01.lab.local 443
bind servicegroup svcgrp_ex2016_ecp EX02.lab.local 443
bind servicegroup svcgrp_ex2016_ecp -monitorName mon_ecp

4.5 Load Balancer

vServer

IP address

Method

Persistence

Timeout

Protocol

Authentication (AAA)

SMTP

192.168.2.248

Least Connection

NONE

Default

TCP

IMAP

192.168.2.248

Least Connection

NONE

Default

TCP

OWA

0.0.0.0

Least Connection

NONE

Default

SSL

FBA

ECP

0.0.0.0

Least Connection

NONE

Default

SSL

FBA

ActiveSync

0.0.0.0

SRCIPDESTIP

NONE

Default

SSL

401

AutoDiscover

0.0.0.0

SourceIP

NONE

30

SSL

401

RPC

0.0.0.0

Least Connection

SOURCEIP

30

SSL

401

EWS

0.0.0.0

Least Connection

NONE

Default

SSL

401

OAB

0.0.0.0

Least Connection

NONE

Default

SSL

401

MAPI

0.0.0.0

Least Connection

SOURCEIP

30

SSL

401

#Create Load Balancer
add lb vserver lb_vsrv_ex2016_smtp_25 TCP 192.168.2.248 25
add lb vserver lb_vsrv_ex2016_smtp_465 TCP 192.168.2.248 465
add lb vserver lb_vsrv_ex2016_smtp_587 TCP 192.168.2.248 587
add lb vserver lb_vsrv_ex2016_imap_143 TCP 192.168.2.248 143
add lb vserver lb_vsrv_ex2016_imap_993 TCP 192.168.2.248 993
add lb vserver lb_vsrv_ex2016_owa SSL 0.0.0.0 0 -persistenceType NONE
add lb vserver lb_vsrv_ex2016_activesync SSL 0.0.0.0 0 -persistenceType SRCIPDESTIP
add lb vserver lb_vsrv_ex2016_rpc SSL 0.0.0.0 0 -persistenceType SOURCEIP -timeout 30
add lb vserver lb_vsrv_ex2016_ews SSL 0.0.0.0 0 -persistenceType NONE
add lb vserver lb_vsrv_ex2016_autodiscover SSL 0.0.0.0 0 -persistenceType SOURCEIP -timeout 30
add lb vserver lb_vsrv_ex2016_oab SSL 0.0.0.0 0 -persistenceType NONE
add lb vserver lb_vsrv_ex2016_mapi SSL 0.0.0.0 0 -persistenceType SOURCEIP -timeout 30
add lb vserver lb_vsrv_ex2016_ecp SSL 0.0.0.0 0 -persistenceType NONE
#Bind Service Groups to vServer
bind lb vserver lb_vsrv_ex2016_smtp_25 svcgrp_ex2016_smtp_25
bind lb vserver lb_vsrv_ex2016_smtp_465 svcgrp_ex2016_smtp_465
bind lb vserver lb_vsrv_ex2016_smtp_587 svcgrp_ex2016_smtp_587
bind lb vserver lb_vsrv_ex2016_imap_143 svcgrp_ex2016_imap_143
bind lb vserver lb_vsrv_ex2016_imap_993 svcgrp_ex2016_imap_993
bind lb vserver lb_vsrv_ex2016_owa svcgrp_ex2016_owa
bind lb vserver lb_vsrv_ex2016_activesync svcgrp_ex2016_activesync
bind lb vserver lb_vsrv_ex2016_rpc svcgrp_ex2016_rpc
bind lb vserver lb_vsrv_ex2016_ews svcgrp_ex2016_ews
bind lb vserver lb_vsrv_ex2016_autodiscover svcgrp_ex2016_autodisover
bind lb vserver lb_vsrv_ex2016_oab svcgrp_ex2016_oab
bind lb vserver lb_vsrv_ex2016_mapi svcgrp_ex2016_mapi
bind lb vserver lb_vsrv_ex2016_ecp svcgrp_ex2016_ecp
#Bind SSL certificate
#Replace certificate name
bind ssl vserver lb_vsrv_ex2016_owa -certkeyName 'Wildcard-Flashmob'
bind ssl vserver lb_vsrv_ex2016_activesync -certkeyName 'Wildcard-Flashmob'
bind ssl vserver lb_vsrv_ex2016_rpc -certkeyName 'Wildcard-Flashmob'
bind ssl vserver lb_vsrv_ex2016_ews -certkeyName 'Wildcard-Flashmob'
bind ssl vserver lb_vsrv_ex2016_autodiscover -certkeyName 'Wildcard-Flashmob'
bind ssl vserver lb_vsrv_ex2016_oab -certkeyName 'Wildcard-Flashmob'
bind ssl vserver lb_vsrv_ex2016_mapi -certkeyName 'Wildcard-Flashmob'
bind ssl vserver lb_vsrv_ex2016_ecp -certkeyName 'Wildcard-Flashmob'

4.6 Content Switch

Name

Action

Target

Expression

cs_pol_owa

cs_act_owa

lb_vsrv_ex2016_owa

HTTP.REQ.URL.SET_TEXT_MODE(IGNORECASE).CONTAINS(“/owa”)

cs_pol_ews

cs_act_ews

lb_vsrv_ex2016_ews

HTTP.REQ.URL.SET_TEXT_MODE(IGNORECASE).CONTAINS(“/ews”)

cs_pol_activesync

cs_act_activesync

lb_vsrv_ex2016_activesync

HTTP.REQ.URL.SET_TEXT_MODE(IGNORECASE).CONTAINS(“Microsoft”)

cs_pol_autodiscover

cs_act_autodiscover

lb_vsrv_ex2016_autodiscover

HTTP.REQ.URL.SET_TEXT_MODE(IGNORECASE).CONTAINS(“/autodiscover”)

cs_pol_rpc

cs_act_rpc

lb_vsrv_ex2016_rpc

HTTP.REQ.URL.SET_TEXT_MODE(IGNORECASE).CONTAINS(“/rpc”)

cs_pol_ews

cs_act_ews

lb_vsrv_ex2016_ews

HTTP.REQ.URL.SET_TEXT_MODE(IGNORECASE).CONTAINS(“/ews”)

cs_pol_oab

cs_act_oab

lb_vsrv_ex2016_oab

HTTP.REQ.URL.SET_TEXT_MODE(IGNORECASE).CONTAINS(“/oab”)

cs_pol_mapi

cs_act_mapi

lb_vsrv_ex2016_mapi

HTTP.REQ.URL.SET_TEXT_MODE(IGNORECASE).CONTAINS(“/mapi”)

cs_pol_cgi

cs_act_owa

lb_vsrv_ex2016_owa

HTTP.REQ.URL.SET_TEXT_MODE(IGNORECASE).CONTAINS(“/cgi”)

cs_pol_owa_redirect

cs_act_owa

lb_vsrv_ex2016_owa

HTTP.REQ.HOSTNAME.EQ(“mail.flashmob-saulgau.de”)

#Create Content Switch
#Replace IP address of Content Switch
add cs vserver cs_exchange2016_http HTTP 192.168.1.20 80
add cs vserver cs_exchange2016_ssl SSL 192.168.1.20 443
#Replace certificate name
bind ssl vserver cs_exchange2016_ssl -certkeyName 'Wildcard-Flashmob'
#Create Content Switch Policies
add cs action cs_act_owa -targetLBVserver lb_vsrv_ex2016_owa
add cs policy cs_pol_owa -rule 'HTTP.REQ.URL.SET_TEXT_MODE(IGNORECASE).CONTAINS("/owa")' -action cs_act_owa
add cs action cs_act_ews -targetLBVserver  lb_vsrv_ex2016_ews
add cs policy cs_pol_ews -rule 'HTTP.REQ.URL.SET_TEXT_MODE(IGNORECASE).CONTAINS("/ews")' -action cs_act_ews
add cs action cs_act_autodiscover -targetLBVserver  lb_vsrv_ex2016_autodiscover
add cs policy cs_pol_autodiscover -rule 'HTTP.REQ.URL.SET_TEXT_MODE(IGNORECASE).CONTAINS("/autodiscover")' -action cs_act_autodiscover
add cs action cs_act_activesync -targetLBVserver  lb_vsrv_ex2016_activesync
add cs policy cs_pol_activesync -rule 'HTTP.REQ.URL.SET_TEXT_MODE(IGNORECASE).CONTAINS("Microsoft")' -action cs_act_activesync
add cs action cs_act_oab -targetLBVserver  lb_vsrv_ex2016_oab
add cs policy cs_pol_oab -rule 'HTTP.REQ.URL.SET_TEXT_MODE(IGNORECASE).CONTAINS("/oab")' -action cs_act_oab
add cs action cs_act_mapi -targetLBVserver  lb_vsrv_ex2016_mapi
add cs policy cs_pol_mapi -rule 'HTTP.REQ.URL.SET_TEXT_MODE(IGNORECASE).CONTAINS("/mapi")' -action cs_act_mapi
add cs action cs_act_rpc -targetLBVserver  lb_vsrv_ex2016_rpc
add cs policy cs_pol_rpc -rule 'HTTP.REQ.URL.SET_TEXT_MODE(IGNORECASE).CONTAINS("/rpc")' -action cs_act_rpc
add cs action cs_act_ecp -targetLBVserver  lb_vsrv_ex2016_ecp
add cs policy cs_pol_ecp -rule 'HTTP.REQ.URL.SET_TEXT_MODE(IGNORECASE).CONTAINS("/ecp")' -action cs_act_ecp
#OWA Fix https://support.citrix.com/article/CTX209060
add cs policy cs_pol_cgi -rule 'HTTP.REQ.URL.SET_TEXT_MODE(IGNORECASE).CONTAINS("/cgi")' -action cs_act_owa
#Redirect to OWA if only https://mail.flashmob-saulgau.de will be entered
#Replace the mail FQDN
add cs policy cs_pol_owa_redirect -rule 'HTTP.REQ.HOSTNAME.EQ("mail.flashmob-saulgau.de")' -action cs_act_owa
#Bind Content Switch Policies
bind cs vserver cs_exchange2016_ssl -policyName cs_pol_owa -priority 100
bind cs vserver cs_exchange2016_ssl -policyName cs_pol_ews -priority 110
bind cs vserver cs_exchange2016_ssl -policyName cs_pol_autodiscover -priority 120
bind cs vserver cs_exchange2016_ssl -policyName cs_pol_activesync -priority 130
bind cs vserver cs_exchange2016_ssl -policyName cs_pol_oab -priority 140
bind cs vserver cs_exchange2016_ssl -policyName cs_pol_mapi -priority 150
bind cs vserver cs_exchange2016_ssl -policyName cs_pol_rpc -priority 160
bind cs vserver cs_exchange2016_ssl -policyName cs_pol_ecp -priority 170
bind cs vserver cs_exchange2016_ssl -policyName cs_pol_cgi -priority 180
bind cs vserver cs_exchange2016_ssl -policyName cs_pol_owa_redirect -priority 190
#OWA HTTP Redirect (Responder)
#Replace the mail FQDN
add responder action resp_act_owa redirect '"https://"+HTTP.REQ.HOSTNAME+"/owa/"'
add responder policy resp_pol_owa 'HTTP.REQ.HOSTNAME.CONTAINS("mail.flashmob-saulgau.de")' resp_act_owa
bind cs vserver cs_exchange2016_http -policyName resp_pol_owa -priority 100

4.7 AAA (Enterprise)

If you have an enterprise licence you can let take the authenication on the AAA server and redirect the credentials to OWA. This feature offers improved security integration and n-factor authentication like RADIUS, SAML and certificate authentication is possible. If you enter the mail domain you will be redirected to the AAA login page.

aaa

If you want to you use “401 Based Authentication” on the Autodiscover service you need to set the following registry key in the user profile.

HKCU\SOFTWARE\Microsoft\Office\16.0\Common\Identity\EnableADAL (REG_DWORD 0)

Otherwise Outlook 2016 is crashing while setting up the profile (ADAL is enabled by default)
NetScaler is not supporting ADAL at the moment.
https://discussions.citrix.com/topic/376086-outlook-2016-and-autodiscover/

Update (2018-05-23): When using NetScaler >= 12.0 there is no need to create the “EnableADAL” key. https://support.citrix.com/article/CTX216539

#Enable AAA Feature
enable ns feature AAA
#Create AAA Server
add authentication vserver AAA_Exchange_2016 SSL 0.0.0.0
#Replace certificate name
bind ssl vserver AAA_Exchange_2016 -certkeyName 'Wildcard-Flashmob'
bind authentication vserver AAA_Exchange_2016 -portaltheme X1
#Replace AAA FQDN
set authentication vserver AAA_Exchange_2016 -authenticationDomain 'flashmob-saulgau.de'

4.7.1 Authentication Policies

In this setup we  will authenticate with LDAP only. For this we need create two policies.

1.) LDAP with sAMAccountName
2.) LDAP with userPrincipalName

The user can login with “test” or “test@lab.local”.

#LDAP SAM + UPN Policy
#Replace server ip, ldapbase, bind user and password
add authentication ldapaction LDAP_UPN -serverip 192.168.2.1 -secType SSL -serverPort 636 -ldapBase "DC=lab,DC=local" -ldapBindDn ns-ldap@lab.local -ldapBindDnPassword ##password## -ldapLoginName userPrincipalName -groupAttrName "memberOf" -subAttributeName "cn" -ssoNameAttribute userPrincipalName -passwdChange ENABLED -followReferrals ON
add authentication ldapaction LDAP_SAM -serverip 192.168.2.1 -secType SSL -serverPort 636 -ldapBase "DC=lab,DC=local" -ldapBindDn ns-ldap@lab.local -ldapBindDnPassword ##password## -ldapLoginName sAMAccountName -groupAttrName "memberOf" -subAttributeName "cn" -ssoNameAttribute userPrincipalName -passwdChange ENABLED -followReferrals ON
add authentication ldappolicy LDAP_UPN ns_true LDAP_UPN
add authentication ldappolicy LDAP_SAM ns_true LDAP_SAM
#Bind LDAP Policies
bind authentication vserver AAA_Exchange_2016 -policy LDAP_UPN -priority 100
bind authentication vserver AAA_Exchange_2016 -policy LDAP_SAM -priority 110

4.7.2 SSO Traffic Policies

#Create AAA Session Policy
#Replace "ssoDomain"
add tm sessionAction tm_act_exchange2016_owa_sso -defaultAuthorization ALLOW -SSO ON -ssoDomain 'lab.local'
add tm sessionPolicy tm_pol_exchange2016_owa_sso 'HTTP.REQ.URL.CONTAINS("/owa/auth/logon.aspx")' tm_act_exchange2016_owa_sso
#Create SSO Form and Policies
add tm formSSOAction sso_profile_exchange_2016_owa -actionURL "/owa/auth.owa" -userField "username" -passwdField "password" -responsesize "60000" -ssoSuccessRule 'HTTP.RES.SET_COOKIE.COOKIE("cadata").VALUE("cadata").LENGTH.GT(70)' -nvtype DYNAMIC -submitMethod POST

add tm trafficAction traffic_prof_exchange_2016_owa -SSO ON -appTimeout 1 -formSSOAction sso_profile_exchange_2016_owa
add tm trafficAction traffic_prof_exchange_2016_owa_logout -InitiateLogout ON

add tm trafficPolicy traffic_pol_exchange_2016_owa 'HTTP.REQ.URL.CONTAINS("/owa/auth/logon.aspx")' traffic_prof_exchange_2016_owa
add tm trafficPolicy traffic_pol_exchange_2016_owa_logout 'HTTP.REQ.URL.CONTAINS("/owa/logoff.owa")' traffic_prof_exchange_2016_owa_logout
#Bind SSO Policies to the OWA vServer
bind lb vserver lb_vsrv_ex2016_owa -policyName traffic_pol_exchange_2016_owa -priority 100 -gotoPriorityExpression END -type REQUEST
bind lb vserver lb_vsrv_ex2016_owa -policyName traffic_pol_exchange_2016_owa_logout -priority 110 -gotoPriorityExpression END -type REQUEST
#Set FBA and 401 authentication
#Replace AuthenticationHost FQDN
set lb vserver lb_vsrv_ex2016_owa -Authentication ON -authnVsName AAA_Exchange_2016 -AuthenticationHost aaa.flashmob-saulgau.de
set lb vserver lb_vsrv_ex2016_ecp -Authentication ON -authnVsName AAA_Exchange_2016 -AuthenticationHost aaa.flashmob-saulgau.de
set lb vserver lb_vsrv_ex2016_activesync -authn401 ON -authnVsName AAA_Exchange_2016
set lb vserver lb_vsrv_ex2016_autodiscover -authn401 ON -authnVsName AAA_Exchange_2016
set lb vserver lb_vsrv_ex2016_rpc -authn401 ON -authnVsName AAA_Exchange_2016
set lb vserver lb_vsrv_ex2016_ews -authn401 ON -authnVsName AAA_Exchange_2016
set lb vserver lb_vsrv_ex2016_oab -authn401 ON -authnVsName AAA_Exchange_2016
set lb vserver lb_vsrv_ex2016_mapi -authn401 ON -authnVsName AAA_Exchange_2016
#Content Switch AAA
#Replace AuthenticationHost FQDN
add cs action cs_act_aaa -targetVserver AAA_Exchange_2016
add cs policy cs_pol_aaa -rule 'HTTP.REQ.HOSTNAME.EQ("aaa.flashmob-saulgau.de")' -action cs_act_aaa
bind cs vserver cs_exchange2016_ssl -policyName cs_pol_aaa -priority 90

The priorty of the AAA content switch policy must be the one with the lowest priority.

4.7.3 Group Filtering

If you need to restrict the external access to security groups in Active Directory, create the following authorization policies.

#Group Filtering
#Replace AD Groups
add authorization policy pol_auth_owa "HTTP.REQ.USER.IS_MEMBER_OF(\"External-OWA\").NOT" DENY
add authorization policy pol_auth_outlook "HTTP.REQ.USER.IS_MEMBER_OF(\"External-Outlook\").NOT" DENY
add authorization policy pol_auth_activesync "HTTP.REQ.USER.IS_MEMBER_OF(\"External-ActiveSync\").NOT" DENY

Bind the authorization policies to the vServers.

bind lb vserver lb_vsrv_ex2016_owa -policyName pol_auth_owa -priority 100 -gotoPriorityExpression END -type REQUEST
bind lb vserver lb_vsrv_ex2016_ecp -policyName pol_auth_owa -priority 100 -gotoPriorityExpression END -type REQUEST
bind lb vserver lb_vsrv_ex2016_rpc -policyName  pol_auth_outlook -priority 100 -gotoPriorityExpression END -type REQUEST
bind lb vserver lb_vsrv_ex2016_mapi -policyName pol_auth_outlook -priority 100 -gotoPriorityExpression END -type REQUEST
bind lb vserver lb_vsrv_ex2016_ews -policyName pol_auth_outlook -priority 100 -gotoPriorityExpression END -type REQUEST
bind lb vserver lb_vsrv_ex2016_oab -policyName pol_auth_outlook -priority 100 -gotoPriorityExpression END -type REQUEST
bind lb vserver lb_vsrv_ex2016_activesync -policyName pol_auth_activesync -priority 100 -gotoPriorityExpression END -type REQUEST

When your user is not in the “External-OWA” group and the authentication against the AAA server was succesfull you will get the following notification:

“Error: Not a privileged User.”

I created a responder html page, to present a more user friendly message. This can’t be done via CLI. Go to AppExpert –> Responder –> HTML Page Imports

You are not authorized to use the OWA service.
Please contact the Helpdesk.
0049 - 0000 - 0000
helpdesk@flashmob-saulgau.de

2018-05-23 15_02_53-Citrix NetScaler VPX - Configuration

Now you can create the responder policy & action.

#OWA Deny Responder
add responder action resp_act_owa_deny respondwithhtmlpage html_owa -responseStatusCode 200
add responder policy resp_pol_owa_deny "HTTP.REQ.USER.IS_MEMBER_OF(\"External-OWA\").NOT" resp_act_owa_deny
bind lb vserver lb_vsrv_ex2016_owa -policyName resp_pol_owa_deny -priority 100 -gotoPriorityExpression END -type REQUEST

4.8 Front End Optimization (Enterprise)

I couldnt test this feature too much so I configured like descriped in the Citrix whitepaper. If the optimization action “Moderate” is not suiting your expectations you can try the “Aggresive” mode. You can verify if FOE is working within the GUI. Go to Optimization –> Front End Optimization –> Statics (“stat feo” in CLI)

foe1

foe2

#Enable Front End Optimization
enable ns feature FEO
#Front End Optimization
#Replace FQDN
add feo policy feo_pol_exchange2016 'HTTP.REQ.HOSTNAME.CONTAINS("mail.flashmob-saulgau.de")' MODERATE
bind cs vserver cs_exchange2016_ssl -policyName feo_pol_exchange2016 -priority 100

4.9 Integrated Caching (Platinum)

In the Citrix docs its recommended to allocate less than half of the NetScalers memory for integrated caching. Set the parameter “memLimit” fitting to your appliance. I’m using 500MB. You can verify if the cache is working within the GUI. Go to Optimization –> Integrated Caching –> View Cache Objects (“show cache object” in CLI)

cache1

cache2

#Enable Integrated Caching
enable ns feature IC<span id="mce_SELREST_start" style="overflow:hidden;line-height:0;"></span>
#Integrated Caching
set cache parameter -memLimit 500
set serviceGroup svcgrp_ex2016_owa -CMP YES
set serviceGroup svcgrp_ex2016_activesync -CMP YES
set serviceGroup svcgrp_ex2016_rpc -CMP YES
set serviceGroup svcgrp_ex2016_ews -CMP YES
set serviceGroup svcgrp_ex2016_autodisover -CMP YES
set serviceGroup svcgrp_ex2016_oab -CMP YES
<span id="mce_SELREST_start" style="overflow:hidden;line-height:0;"></span>set serviceGroup svcgrp_ex2016_mapi -CMP YES
set serviceGroup svcgrp_ex2016_ecp -CMP YES

add cache contentGroup <span id="mce_SELREST_end" style="overflow:hidden;line-height:0;"></span>cache_group_exchange2016 -type HTTP -weakNegRelExpiry 233 -weakPosRelExpiry 233
add cache policy cache_pol_exchange2016 -rule 'TRUE' -action CACHE -storeInGroup cache_group_exchange2016

bind cs vserver cs_exchange2016_ssl -policyName cache_pol_exchange2016 -priority 100 -type REQUEST

I hope this guide helped you to load balance Exchange with Citrix NetScaler.
If you find any misconfigurations or have improvments please contact me.

118 thoughts on “Citrix Netscaler – Loadbalancing Exchange 2013/2016 (Walkthrough Guide)

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  1. hi julian, awesome blog thank you for that, and i love to have directly the netscaler commands not the GUI. i did create after 2 days same netscaler config, but for me in all of this guides, it is not normal to make also the loadbalancing steps also for the SMTP and IMAP Traffic? I mean, what is the BestPractice here? Only Loadbalance SMTP Port25 or also Port 587, 143 and so on? Or did that make Exchange 2016 with other Tools? regards frank

    Like

  2. hi julian, i have make this, only on the monitors i am not sure, if there is maybe a better monitor as http-evc

    # Create and Bind LB Server for SMTP Traffic / only for SMTP Traffic / when you want / must be configured with Exchange Admin / Relay Rules than on Netscaler
    # Create and Bind LB Server for SMTP Traffic Port 25 and Port 465 and Port 587 and also IMAP Port 143
    add serviceGroup lb_svg_exch2016_smtp TCP
    add lb vserver lb_exch2016_vsrv_smtp TCP 192.168.0.11 25
    bind lb vserver lb_exch2016_vsrv_smtp lb_svg_exch2016_smtp
    bind serviceGroup lb_svg_exch2016_smtp exchange01.your.domain 25
    bind serviceGroup lb_svg_exch2016_smtp exchange02.your.domain 25
    bind serviceGroup lb_svg_exch2016_smtp -monitorName tcp
    add serviceGroup lb_svg_exch2016_smtp_587 TCP
    add lb vserver lb_exch2016_vsrv_smtp_587 TCP 192.168.0.11 587
    bind lb vserver lb_exch2016_vsrv_smtp_587 lb_svg_exch2016_smtp_587
    bind serviceGroup lb_svg_exch2016_smtp_587 exchange01.your.domain 587
    bind serviceGroup lb_svg_exch2016_smtp_587 exchange02.your.domain 587
    bind serviceGroup lb_svg_exch2016_smtp_587 -monitorName tcp
    add serviceGroup lb_svg_exch2016_imap TCP
    add lb vserver lb_exch2016_vsrv_imap TCP 192.168.0.11 143
    bind lb vserver lb_exch2016_vsrv_imap lb_svg_exch2016_imap
    bind serviceGroup lb_svg_exch2016_imap exchange01.your.domain 143
    bind serviceGroup lb_svg_exch2016_imap exchange02.your.domain 143
    bind serviceGroup lb_svg_exch2016_imap -monitorName tcp
    add serviceGroup lb_svg_exch2016_smtp_465 TCP
    add lb vserver lb_exch2016_vsrv_smtp_465 TCP 192.168.0.11 465
    bind lb vserver lb_exch2016_vsrv_smtp_465 lb_svg_exch2016_smtp_465
    bind serviceGroup lb_svg_exch2016_smtp_465 exchange01.your.domain 465
    bind serviceGroup lb_svg_exch2016_smtp_465 exchange02.your.domain 465
    bind serviceGroup lb_svg_exch2016_smtp_465 -monitorName tcp

    maybe you make it same or better
    regards frank

    Liked by 1 person

  3. Nice post. Quick question.

    If I create a LB VIP on the NetScaler with port/protocol of */ANY to the back-end CAS servers, All of the services work fine, OWA, Active Sync, OAB, RPC, etc, all function..

    BY following the guide it breaks my outlook clients (externally) they prompt for password continuously and users cannot login.

    Any ideas?

    Like

  4. How do you configure IMAP monitor for Exchange 2013? Netscaler routes traffic to Exchange even if the server is in maintenance mode because it sees that port 993 is available. Based from packet capture, it is receiving acknowledgement from the server when it checks port 993. Once the traffic is routed to Exchange, it fails because the associated IMAP service is in maintenance mode.

    Like

  5. Hi Julian,

    great blog. Help so much.
    But I have some questions about the general structure of your topology, because I am also quite new to NetScaler.

    1. Where do you need the LB VIP 192.168.2.248? According to the sketch, the internal clients alsoconnect to CS VIP?! And there is no reference to the LB VIP … should it have to be entered internally somewhere?
    2. Where do you use an external IP – mentioned in requirements? I find in your deployment only the internal CS VIP. Where and how should I set up the external address? Another CS for external or how is externel traffic redirected to internal CS VIP?

    Thank you in advance

    Greetings Kevin

    Like

    1. Hi Kevin,
      1.) The LB VIP .248 is only for load balancing IMAP/SMTP traffic. Internal Clients should connect to the internal NetScaler appliance. If you only have a NetScaler in the DMZ you can create an additional vServer without AAA authenication and create a dns record which pointing to the VIP.
      2.) For the external access you need to create a DNAT to your NetScaler CS VIP. Internal access is going directly to the Content Switch.
      Greets
      Julian

      Like

      1. Hey Julian,
        Thank you very much. Your explanation helped me a lot. Then I have only one more question.
        If I was slipping internal Clients, as well as external Clients via a NetScaler in the DMZ, would I create another LB vServer for each Exchange LB (SMTP, IMAP, OWA, EWS, …) without attached AAA? And would I need a second CS vServer (internal use) without AAA?
        If so, is this a possible setup?:
        > external IP via INAT to CS VIP (with AAA for external)
        – > LB VIP for SMTP and IMAP (with AAA for external)
        – > LBs 0.0.0.0 for OWA, autodiscover, … (with AAA for external)
        >CS VIP (without AAA for internal)
        – > LB VIP for SMTP and IMAP (without AAA for internal)
        – > LBs 0.0.0.0 for OWA, autodiscover, … (with AAA for external)
        Is this a clean and supported solution or is there some mistake?
        Or can this be done with CS policies (for internal and external clients) an the same CS forwarding to different LB VIPs?
        Thank you again 🙂
        Greetings Kevin

        Like

      2. You Need to setup vServer with and without AAA enabled. You are correct 😉
        – lb_owa_external
        – lb_owa_internal
        In big environments you normaly have an internal NetScaler pair and can just create a Service on the DMZ NS which is pointing to the internal OWA LB. Then Setup a LB vServer, specify the Service (Internal) and enable AAA.
        Greets
        Julian

        Like

      3. Hi Julian,
        Thank you for your answers so far. They help me a lot to get deeper into Netscaler.
        So I only need two different LB vServers (one for OWA internally without AAA and one for OWA externally with AAA).
        But what would a policy look like at CS VIP that can distinguish whether request is for internal or external OWA LB vServer?
        Or is a second CS needed just for external requests?
        Greetings Kevin

        Like

      4. Method 1 – You could create CS Policy which is filtered by the requested Hostname/URL and the Client Source IP (CLIENT.IP.SRC.IN_SUBNET(x.x.x.x/x)
        Method 2 – Create a second CS and Point internal DNS requests to this VIP

        Like

  6. Hi Julian,

    Great blog. This is far better explained and indepth than what the “official” Citrix documentation recommends.

    One question:
    In your scenario you use one IP address for the HTTP/HTTPS Content Switch and another IP address for SMTP and IMAP.
    Presumably this means that Outlook and OWA would connect to one DNS A record (e.g. mail.domain.com) and SMTP and IMAP would connect to another (e.g. smtp.domain.com).

    Is it possible to use just one IP address for HTTP, HTTPS, SMTP and IMAP?

    The reason I’m asking is because there are currently around 300 servers and printers using SMTP relay to send email to a plethora of different DNS entries pointing at the old Exchange environment and it’d be quite a daunting task to update them to point at the correct DNS A record that is pointing at the SMTP/IMAP load balanced VIP.

    Kind regards
    David

    Like

    1. Of course, you can create a Content Switch with the IP 192.168.2.240 (HTTPS) and a Load-Balancing vServer using the same ip address with your SMTP/IMAP ports. Keep in mind: You can not use the same port for a single ip address.
      Valid:
      CS – 192.168.2.240 – SSL – 443 (OWA)
      LB – 192.168.2.240 – TCP – 25 (SMTP)
      LB – 192.168.2.240 – TCP – 143 (IMAP)
      Not valid:
      CS – 192.168.2.240 – SSL – 443 (OWA)
      LB – 192.168.2.240 – TCP – 443 (SMTP)
      LB – 192.168.2.240 – TCP – 143 (IMAP)

      Like

  7. Excellent article Julian!
    I am running into a little authentication issue with this setup, and I was hoping you can guide me in the right direction, we are not using any of the features highlighted in 4.7, 4.8 and 4.9. I also added an entry for the powershell virtual directory.
    Phones, OWA and ECP are working as expected but the Outlook clients (2010 and 2016 in online mode because we use Citrix lol) keep prompting for credentials and for some reason I can’t get passed that. I was able to connect once using Outlook 2010 but as soon as I closed it I was challenged with the credentials prompt again.
    Any ideas? Do we need to enable AAA?
    Thanks a lot!

    Like

    1. You don’t need AAA. It’s only for improved security implementation. Can you see a failed login attempt in the Exchange Security eventlog? Are you using NTLM or Kerberos authentication for RPC/MAPI?
      Julian

      Like

      1. Thanks for getting back to me so soon.
        Unfortunately the logs already rolled, but I’ll try to catch it tonight.
        What I noticed is that the MAPI virtual directory on one of our Exchange servers is set to Ntlm,Negotiate,OAuth and the other one for some reason is set to Ntlm,Negotiate, I’m going to make sure both are set to Ntlm,Negotiate,OAuth and then try this exercise again, thanks for the tip.
        We are still in the middle of the migration so we also have some RPC connections going back to the Exchange 2010 CAS servers for Public Folder access, there is an lb vserver (*/any) going to back to the CAS servers that will decommissioned once the migration is completed, could this be a factor as well?
        Thanks again.

        Like

      2. Julian,
        I was able to bypass the Outlook authentication issue by setting the MAPI persistence to SOURCEIP as defined here: https://www.citrix.com/content/dam/citrix/en_us/documents/guide/deploying-netscaler-with-microsoft-exchange-2016.pdf
        I definitely like your approach a lot more, but couldn’t figure out what was preventing me from logging in, I saw the header in Fiddler and that’s what made me switch the persistence.
        Any thoughts?
        And again many thanks!

        Like

  8. Hi Julian,
    Little mistake at the commands at chapter 4.8
    #Enable Front End Optimization
    enable ns feature FEO
    #Front End Optimization
    #Replace FQDN
    add feo policy feo_pol_exchange2016 ‚HTTP.REQ.HOSTNAME.CONTAINS(„mail.flashmob-saulgau.de“)‘ MODERATE
    bind lb vserver cs_exchange2016_ssl -policyName feo_pol_exchange2016 -priority 100
    I think you would like to bind the FEO Policy to the CS vServer, not a LB vServer, so
    bind cs vserver cs_exchange2016_ssl -policyName feo_pol_exchange2016 -priority 100
    would be correct.
    Thanks for your article, very good Job!
    Regards
    Julian 😉

    Like

      1. Thanks Julian! One more question: if you activate AAA for autodiscover, will you be redirected only for first time ocnfiguration, or will this ocure more than once? can this be seen as a 2-factor auth. for outlook sync if you do not use mapioverhttp?`

        Like

      2. After you have been authenticated to the AAA Server the credentials can be used for different sevices. After you logout for example from OWA Service you Need to Login again to use AutoDiscover or ECP. It’s No 2-Factor.

        Like

  9. I’m starting to feel dumb because I have followed 3 guides like this to load balance Exchange 2016 and I can’t get it to work!

    After following all the steps in this guide I then simulate a server failure by disconnecting the NIC and everything works great at this stage but if I simulate a SERVICE failure by stopping the web service then my Outlook disconnects and I can’t use OWA/ECP anymore. Is this expected behaviour? I can see the services like owa/ecp/ews/etc as being down on the Netscaler but Outlook is disconnected and OWA/ECP in a browser doesn’t work (I get error 500 or 503). Only after starting the web service again does everything start to work again.

    Any ideas?

    Like

  10. Great walkthrough. Have this working in the lab for Exchange 2013 (had to disable the FrontEndOptimization to get to work properly will have to look into that). But other than that it works great. I do have a question.

    Not being an Exchange admin can you tell me how much different the configuration would be to support Exchange 2010?

    Like

      1. So in theory it should work as long as modify the health checks? And possibly use the „PBack“ insert method? Basically I have tried the same configuration and its not passing SSO. Everything else seems to be ok. I just disabled monitoring on the services for testing. I will keep at it. Thanks for the reply.

        Like

      2. Thank you for the article link. I had been trying both methods. It appears the rewrite is getting hits but still no SSO. I am assuming the PBack Cookie is not being passed from the AAA. I will take a NetScaler/Wireshark trace and see what it shows. Not sure exactly where to look but the plan would be to capture directly hitting OWA (which fiddler shows the PBACK) and then capture the AAA traffic once it stops on the OWA page where I don’t see PBack Cookie.

        Like

      3. Was able to get this to pass the SSO for 2010 by adding in a “Name Value Pair” and setting it to Static vs Dynamic on the SSO Profile.

        Like

  11. The MAPI LB vServer is showing as up/healthy. I did get a popup for my password when opening Outlook but after changing persistence to SOURCEIP this got Outlook to connect again so thanks!

    The next issue I keep getting is that when I stop the web service on one of the mailbox servers to simulate a service failure Outlook then disconnects and when I try to login to OWA/ECP I get a blank page? The Netscaler is correctly showing that the service group is partially down but I still can’t use Outlook/OWA/ECP. Any ideas?

    Like

  12. I guess I should first ask, if I stop the web service on one of the Exchange servers, should Outlook/OWA/ECP continue to work on the other servers?
    I’m not too familar with Wireshark so what am I looking for?
    I use the URL: owa.domain.com and that always shows in the browsers address bar.
    I’m not using AAA (yet).
    Besides Wireshark is there anything else I can check on the Netscaler to troubleshoot this (like logs etc)?

    Like

  13. Thanks for the help!
    I tried Fiddler and it shows me: HTTP/1.1 503 Service Unavailable (I get this when I stop the web service on one of the Exchange servers)
    Which is odd because I thought the Netscaler should stop sending traffic to a service on a server when it detects that it is down (using the health monitors)?
    Whats interesting is that, if I simulate a server failure (by disconnecting the NIC from my VM) then Outlook/OWA/ECP works perfectly after the failure. It’s only if I simulate a web service failure that I get HTTP/1.1 503 Service Unavailable errors!

    Like

  14. Yes! If I stop the service on EX01 then when I browse owa.domain.com/owa/healthcheck.htm I get a 200 OK EX02.domain.com!
    On the Netscaler I can see the service group showing as partially down.

    Like

  15. When the web service is stopped/disabled, is there anything I could be missing in the Netscaler config (monitors, lb servers etc) where you have to tell the Netscaler to NOT send traffic to services that are in a down state?

    I’m just confused as to why traffic is still being sent to a server that is in a down state?

    Like

  16. So I asked this question on the Exchange forum and basically if you have a service failure (planned or not) the cluster will not work.
    So this wasn’t a Netscaler issue but a design limitation with Exchange.

    Like

      1. What I have been wondering is, why have the healthcheck.htm page for each virtual directory if the cluster goes down with a service failure?

        Like

  17. For whatever reason my outlook clients refused to connect after redirecting my DNS records to the CS vServer. This particular environment was still using RPC for Outlook connectivity with Exchange 2016. Making the following change to the persistence on the RPC LB vServer resolved my issue. I followed BlackJack82’s recommendation and also did the same for MAPI. I am not using AAA, Front End Optimization, or Integrated Caching (4.7 – 4.9).

    add lb vserver lb_vsrv_ex2016_rpc SSL 0.0.0.0 0 -persistenceType SRCIPDESTIP
    add lb vserver lb_vsrv_ex2016_mapi SSL 0.0.0.0 0 -persistenceType SRCIPDESTIP

    Thank you for the great write-up Julian! This was exactly what I needed to get this configured. Thanks

    Like

  18. hi Julian
    this blog is so fantastic, maybe it is time for part2, “restrict smtp relay with URL pattern set file and responder policy” ? i get today this question, and when i look in Citrix Forums, there are many different ways, but i think to make a whitelist with URL pattern set and a responder policy, this will be a very good Option? what did you think about that? is it a blog what you can / want make? thx and best regards
    frank

    Like

  19. Hello Julian nice blog I have one query I want to load balance IMAPS (993) service on Citrix netscaler. I am using exchange 2013 in backend and netscaler 11.0.53 VPX. I have configured the IMAPS successfully but while configuring IMAP account in local email client (outlook) am getting CAS server local certificate warning instead of my Exchange SAN which already installed and mapped on netscaler.
    Please help it’s bit urgent.Thanks in advance.

    Like

    1. Did you Install and cofigure the certificate correctly on your CAS? Sounds more like an Exchange problem. Why are you using IMAP when running Outlook as your mail client?

      Like

      1. Yes certificate installed correctly on CAS as when had tried skipping Citrix loadbalancer and directly using CAS server while configuring the IMAP on local system correct SSL cert it is showing
        But when same query come from Citrix LB then it is showing CAS server local root CA

        Like

  20. hi Julian
    i want allow only a range of ip Adresses that can relay to the Exchange. i want not that everybody from Network can relaying to the smtp/Exchange. that is my Goal. and someone do it with acl what is Network, some do it with URL pattern and a whitelist file, what will be easier to handle. but i am not realy sure, what will best Option for that case.

    Like

    1. Give it a try with that pattern set whitelist regarding my knowledge and what I could find in the edocs this is for Web Traffic (http,https) only and will not work. The best option is always a matter of taste. For me this is a network demand and should be configured on the firewall. When there is a lot of change in the whitelist maybe its the better Option to go with NetScaler ACL because you dont need to ask the network team all the time to change the configuration.

      Like

  21. Thanks for the post, where you have a second site which holds e.g. two of the Exchange DAG members (4 members in total (2 in Primary/2 in DR site) A/A site how would LB work with Netscalers at a site Level please.

    Like

  22. Do you have the recommended IIS and Virtual Directory permissions for authentication to match this config in Netscaler?

    Like

      1. I was load balancing them and going straight to the LB vServer, and moved over to your configuration. As soon as I moved over I have some users that now get a continuous Outlook login prompt, removing the profile and nothing works.

        Like

  23. Not much. On 2 users sitting side by side, one had a slightly higher version of Outlook 2013. Same database and same server. But then another user that had issues had that same slightly higher version as the 2 users sitting side by side.

    Like

  24. Hi Julian,

    Have all your config in place and everything seems to run fine with the exception of anything involving the 401 Authentication for Autodiscover and Activesync. The clients will continuously prompt for credentials.

    If I remove the binding for AAA on either they both work fine. The only client that seems to work with 401 AAA is Outlook 2016, though majority of clients in environment is Outlook 2013. Our NS is version 12.x

    I checked the Authentication LDAP logs and it is accepting the credentials from what I can see. Any ideas?

    Like

      1. Hi Julian,

        I was able to resolve by putting in the following config and binding the policy to both my autodiscover and activesync loadbalancing VIPs:

        add tm trafficAction SSO_Profile -SSO ON -persistentCookie OFF -InitiateLogout OFF
        add tm trafficPolicy SSO true SSO_Profile

        Like

  25. Julian,

    I was wondering if you had a recommendation for the timeout value of the MAPI lb_vsrv; for RPC it is set to 30 minutes so I have started with using that, but has anyone found that to be too short or too long? What are people using for the timeout for MAPI with SOURCEIP persistence?

    add lb vserver lb_vsrv_ex2016_mapi SSL 0.0.0.0 0 -persistenceType RULE -rule ‘HTTP.REQ.HEADER(“Authorization”)’ -timeout 240

    add lb vserver lb_vsrv_ex2016_mapi SSL 0.0.0.0 0 -persistenceType SOURCEIP -timeout 30

    ### As a note, maybe you should update the blog post to replace the persistence to SOURCEIP in general to keep the config up to date with all that’s been learned.

    Also, just wanted to THANK YOU for putting this blog post together. This is by far the most comprehensive write up on configuring LB of Exchange 2016 I have found. It is extremely useful.

    Like

    1. After rethinking I have changed the MAPI timeout to 240 to match what you had recommended for the service when using RULE persistence. I assume that in itself answers the question, but if you have anything to add please let me know.

      add lb vserver lb_vsrv_ex2016_mapi SSL 0.0.0.0 0 -persistenceType SOURCEIP -timeout 240

      Like

      1. Thank you for the quick reply. As I am interpreting it, so long as the LB_VS timeout is longer than the keepalive interval than everything should be good. In that case assuming the TCP keepalive is setup to 15-20 min, than 30 min timeout would be fine. It also then should be the same that keeping it as a 240 min timeout wouldn’t hurt either. I actually left the timeouts as 240 mins to match the service timeout values you had indicated while they were setup as RULE instead of SOURCEIP and so far so good. I have left Outlook clients with both 2010 mailboxes access via 2016 Exchange NetScaler CS VIP / 2016 Exch Servers Proxy and Outlook clients accessing 2016 mailboxes via the CS VIP and haven’t had any issues with the connectivity timing out, disconnecting, or continually prompting for credentials. All 3 of those issues were seen while using the RULE persistence so from what my testing is showing I think everything is now working as it should be without issue with SOURCEIP -timeout 240 for RPC and MAPI.

        If I am misunderstanding that timeout setting and you believe I should change it down to 30 from 240 for some reason please let me know. Otherwise I appreciate the work done and sense of community you have on this topic and wish you a great day!

        Like

      2. You interpreted correctly. Doesn‘t matter if the LB vServer is configured for 30 or 240 minutes timeout. The value configured on the Exchange server will win. Thanks for your feedback. Appreciate it. Wish you a nice weekend 🙂

        Like

  26. Thank you for such a great setup guide. We have a slightly different scenario: Netscaler VIP in the DMZ with similar settings as the above, that then points the authenticated traffic in to the internal Netscaler VIP that handles the load balancing for internal clients to the exchange servers. This setup seems to work fine for Exchange 2010 as it replaced our TMG setup a couple months ago. But now that we’re trying to get it to start using our 2016 servers, it runs into multiple issues. Anything from double logins (once for AAA, and once for Exchange OWA), to not being able to get logged into a 2010 mailbox, but it works with a 2016 mailbox, to just going to a blank page. This also seems to differ based on browser used. Safari and Chrome work mostly as expected though sometimes double logins on each, Firefox always has double logins or just a blank page, and IE is all of the above. And it seems everyone’s setup guide basically has a single netscaler (or HA pair) with 2 vips (1 for AAA and the main vip) that connects directly to AD for authentication and then load balances to any of the exchange 2016 servers.

    Any ideas are greatly appreciated, we’ve been banging our heads against the wall for about a month now with 3 failed attempts at cutting over. Thanks!

    Like

    1. Without AAA everything is working? I configured a NetScaler (Exchange 2010) the day before yesterday with the same commands (excpect the monitors and AAA) –> no problems. I changed the persistence for the MAPI/RPC vServer from RULE to SOURCEIP last week. The RULE expression was somehow denying the authentication for the services. You always got a credential prompt. Do you have this already implemented?
      When using Exchange 2010 your SSO Form action needs to be configured a little bit different. https://support.citrix.com/article/CTX128197
      If you are using a NetScaler in the DMZ & LAN:
      – Create OWA/MAPI services on the DMZ NetScaler (LB VIPs from the LAN NS)
      – Create LB vServer with this services (DMZ)
      – Configure AAA for the LB vServer (DMZ)

      P.S: For testing the OWA SSO just edit your local host file. The webmail URL should resolve to the CS VIP.

      Julian

      Like

      1. The current setup is DMZ netscaler with AAA for pre-auth, that points to the LAN netscaler for load balancing. The LAN netscaler only has the 2010 CAS servers. This is working.

        The new setup (and our test VIPs) is DMZ netscaler with AAA for pre-auth that points to the LAN netscaler for load balancing. the LAN netscaler new test VIP just points to the new Exchange 2016 servers.

        So would we set up the above all on the DMZ netscalers, and have those still point to the LAN netscaler VIP, and should that LAN vip be just load balancing, or should it also have the same setup as above?

        We’re also tossing around the idea to have the DMZ netscaler just go directly to the exchange 2016 servers. Essentially have the setup you describe on both the DMZ netscaler and the LAN netscaler, but have each set of netscalers go directly to the exchange 2016 servers, instead of having the DMZ netscaler point to the LAN netscaler vip.

        Thanks again for your help and blog post!

        Like

  27. Excellent write up on the Citrix side of things! I am curious what if any action I need to take with Exchange send or receive connectors to make this work. Or the URLs for the virtual directories? You must need to do *something*
    Thanks in advance kind sir!

    Like

    1. There is no change at all on the send/receive connector or virtual directories. OWA is configured for FBA (default setting) and your internal and external urls depends on your environment. If there is something unclear feel free to ask.

      Like

      1. Thank you for the quick reply! In the process of writing a reply to clarify my question, I answered it myself. I was getting hung up on the NetScaler’s role in all of this, and over complicated it. The send and receive connectors only manage SMTP flow, which we are doing simple LB on, so I don’t have to worry about Exchange’s mail-flow there. I’m good now! Thanks again!

        Liked by 1 person

  28. Hi Julian excellent blog I have not seen any blog thats better than this one.I just had a small question to you regarding Exchange running on 2 sites with mpx netscalers 8005 enterprise edition on both sites in that setup what is the best way to get HA in case i loose the entire sites as from exchange 2016 dag perspective i have active database on one site and passive on another site and a lagged on the active site issues that i have is if one site goes down my mails stop working. I was wondering if i can have a quick chat with you through email and get some opinion from you.cheers Jack

    Like

  29. Thanks very much for compiling all this information; it was quite helpful.
    One point that might be of interest.. I’ve noticed URLs like GET /owa/prem/15.1.1466.8/resources/images/0/ewsprite1.mouse.css which would potentially match both CONTAINS(„/ews“) and CONTAINS(„/owa“), which makes the CS policy binding priority important (though I notice you have /owa first, presumably for this reason).
    I chose to use HTTP.REQ.URL.PATH.SET_TEXT_MODE(IGNORECASE).STARTSWITH to match the IIS virtual applications (/Autodiscover /EWS etc). It also might be a less costly comparison than CONTAINS.
    Also, it seems that CONTAINS(“Microsoft”) might properly be replaced with STARTSWITH(„/Microsoft-Server-ActiveSync“). I realize that one came from Citrix documentation.

    Like

  30. Hello,
    Thank you for the fantastic blog post!
    I have a little issue, I followed the instructions but after a successful authentication via hostname, the AAA server displays the following error: Target URL not found for redirect after successful login. Please contact your administrator.
    Any idea how to redirect this to OWA?
    Thank you,
    Ryan

    Like

    1. Are you accesing the CS/LB VIP or the AAA server directly? Normaly you get this message when the NSC_TASS cookie is missing on your client. This happens if you browse to the AAA server and login. It’s only working from the LB/CS (Redirection).

      Like

      1. Hello,

        Thank you for the quick reply!

        I changed the priority of the command from 90 to 105, and the cookie appeared:
        bind cs vserver cs_exchange2016_ssl -policyName cs_pol_aaa -priority 90

        Thank you again!

        Liked by 2 people

    2. Beautiful blog post, Julian!! thank you so very much. ran into the issue just as Ryan.
      I had the same issue. “Target URL not found for redirect after successful login. Please contact your administrator.”
      changed the policy binding priority to 105. and it works.
      however, it only works when i enter http://mail.xyz.com and auto Redirects to https://mail.xyz.com.
      if i enter https://xyz.com directly the issue persists. and goes back to target URL not found for redirect after successful login”
      Wondering what i should be doing to fix the Https.

      Like

  31. Hi Julian,
    I have the same issue as Ryan. Note that I did copy&paste (changed values to match my domain) of your commands up to 4.7 as 4.8 and beyond and additional functionality which I will continue later.

    url entered in the browser: https://mail.domain.com/owa

    Here is an optput of the ns.log

    Jul 2 09:58:12 192.168.20.191 07/02/2018:06:58:12 GMT ns-int-1 0-PPE-2 : default AAA Message 71637 0 : „In update_aaa_cntr: Succeeded policy for user testSSO = LDAP_SAM“
    Jul 2 09:58:12 192.168.20.191 07/02/2018:06:58:12 GMT ns-int-1 0-PPE-2 : default SSLVPN Message 71638 0 : „get_session aaa_info flags 91 flags2 0, new webview 0, sess flags2 21, flags3 0 “
    Jul 2 09:58:12 192.168.20.191 07/02/2018:06:58:12 GMT ns-int-1 0-PPE-2 : default AAATM LOGIN 71639 0 : Context testsso@10.0.0.50 – SessionId: 27- User testsso – Client_ip 10.0.0.50 – Nat_ip „Mapped Ip“ – Vserver 192.168.20.193:443 – Browser_type „Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/64.0.3282.140 Safari/537.36 Edge/17.171“ – Group(s) „N/A“
    Jul 2 09:58:12 192.168.20.191 07/02/2018:06:58:12 GMT ns-int-1 0-PPE-2 : default AAATM Message 71640 0 : „AAATM Login: created session for with cookie: “
    Jul 2 09:58:12 192.168.20.191 07/02/2018:06:58:12 GMT ns-int-1 0-PPE-2 : default AAATM Message 71641 0 : „AAATM: LOGIN: invalid redirect url ▒▒^Z“
    Jul 2 09:58:12 192.168.20.191 07/02/2018:06:58:12 GMT ns-int-1 0-PPE-2 : default SSLVPN Message 71642 0 : „AAA Client Handler: Found extended error code 262157, ReqType 16388 request /cgi/login, cookie hdr _ga=GA1.2.1957678141.1529053026; NSC_TASS=/owa“

    Like

    1. Can you check your “Action URL” in the form sso profile? Should be “/owa/auth.owa”.
      Are both traffic policies bound to the OWA LB?
      Is it working without the cs policy “cs_pol_owa_redirect”?

      Like

  32. seemes tha this name needed to be different add cs policy cs_pol_aaa -rule ‘HTTP.REQ.HOSTNAME.EQ(“”)’ -action cs_act_aaa
    I had it point to the same url as the mail server.
    mail.domain.com for both instead of mail.domain.com for owa/ecp and aaa.domain.com for the authentication server.

    Liked by 1 person

  33. We are using the (/xxx/healthcheck.htm) monitors for LB our Exchange 2016 services. I need to disable TLS 1.0 on our Exchange servers for PCI compliance but when I do the healthcheck.htm monitors fail the handshake. When will these work with TLS 1.1 or 1.2.? Or is there a different monitor you recommend that works with TLS 1.2?

    Like

  34. If you follow this guide and use the AAA feature does that mean that ALL of the traffic and requests go to the AAA server first?
    It seems like with the AAA enables the free-busy and calendars do not work….

    Like

  35. I am not a master of Net Scalers but i know Exchange and was asked if we could block everything except activesync and of course mailflow externally. No EWS,, No ECP, no OWA. Internally yes but no external access on those.

    There are 5 exchange servers load balanced with Netscaler.

    I know you can block do this with an F5 and there is a messy way to do this with Kemp but since I am not fully aware of the Netscalar capabilities I thought I would ask in here.

    Like

  36. Hi Julian,
    Thank you so much for this guide it was really helpful and worked like a charm.
    I have Exchange 2013 and the AAA feature active without group filtering.
    The only problem that i have is that the external outlook doesn’t work. I see in the exchange security logs audit failures which say unknown username and password.
    We have ntlm active on outlookAnywhere for internal and external clients. Am I correct that this setup only works when i have basic active as externalauthentification method?
    Login to owa works fine with the same credentials / user / endclient.

    Thank you so much for your help and guide 🙂
    Best,
    Kim

    Like

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