High Availability synchronization failure on NetScaler appliance.

The secondary node sends a SYN packet and reset is observed in this environment.

The following error will appear: 

Oct 27 12:00:01 <local0.info> NS5-Chicago nsconf: nsnet_connectremoteas: failed to connect to host 10.28.153.60
Oct 27 12:00:04 <local0.alert> 10.28.153.61 10/27/2014:17:00:04 GMT NS5-Chicago 0-PPE-0 : EVENT STATECHANGE 14724 0 : Device "self node 10.28.153.61" - State "SYNC Failure - Save remote config failed"

Telnet port 3010 from secondary to primary node will fail and reset on window 8121 is observed within the network trace.

The following is a snippet from the configuration where this issue was troubleshot.

Masked virtual server:
add lb vserver vip_httpredirect_subnet HTTP -Pattern 10.28.153.0 -IPMask 255.255.255.0 80 -persistenceType NONE -cltTimeout 180

NSIPs of the High Availability pair:
set ns config -IPAddress 10.28.153.61 -netmask 255.255.255.0
set ns config -IPAddress 10.28.153.61 -netmask 255.255.255.0

It is recommended to remove the masked virtual server and validate the high availability synchronization. As soon as masked virtual server is removed from the configuration, "SYNC complete" message can be observed in the log files.

Problem Cause

The masked virtual server and the NSIP are configured in the same subnet causing the SYNC FAILURE.

Citrix Documentation - Masking a Virtual Server IP Address
Citrix Documentation - Configuring Synchronization