NetScaler 12.1 'Address already in use' When Configuring a Load Balancing Virtual Server
Article ID: CTX237834
Updated On:
Description
User tried to configure a Load Balance virtual server, but the appliance is showing an "Address already in use" error message. The IP wasn't in use on the appliance.
Resolution
The error message will go away if the Citrix Session Profile is unbound from the Citrix Gateway and editing the profile to remove the FQDN for the StoreFront LBVIP.
or
Remove the URL from the session policy action, reboot the appliance, create the load balance virtual server and add the URL to the session policy action.
or
If there's any A record created in the appliance to bind the FQDN to an IP, remove it, and reboot the appliance. Add it again once the virtual server is created.
or
If the FQDN is resolved by an external DNS, remove the DNS server in the NetScaler configuration and reboot the appliance. Add it again once the virtual server is created.
Problem Cause
Checking the NetScaler services we could see that there was an internal service created for that IP:
for i in /var/nslog/newnslog*; do echo $i; nsconmsg -K $i -d finalstats | egrep '1\.2\.3\.4' | head -1; done
2877 0 1.2.3.4 si_peer_ip server_svc_internal_NSSVC_SSL_www.test.lab:443(vpndbssvc_-1905061678)
newnslog.77
2147 0 1.2.3.4 si_peer_ip server_svc_internal_NSSVC_SSL_www.test.lab:443(vpndbssvc_-1905061678)
newnslog.78
2145 0 1.2.3.4 si_peer_ip server_svc_internal_NSSVC_SSL_www.test.lab:443(vpndbssvc_-1905061678)
newnslog.79
2149 0 1.2.3.4 si_peer_ip server_svc_internal_NSSVC_SSL_www.test.lab:443(vpndbssvc_-1905061678)
newnslog.80
2145 0 1.2.3.4 si_peer_ip server_svc_internal_NSSVC_SSL_www.test.lab:443(vpndbssvc_-1905061678)
newnslog.81
3053 0 1.2.3.4 si_peer_ip server_svc_NSSVC_SSL_0.0.0.0:443(vpndbssvc_-1905061678)
When a URL is added in Session Policy Action, the NetScaler creates an internal service to check the connectivity with the back-end server. In NetScaler 12.1 the IP of that internal resource is being checked in order to avoid to be used in a virtual server and cause a duplicated IP in the network.
