Unable to resolve DNS host names - Netscaler

Issue: the name servers have been configured as explained in this article

http://support.citrix.com/article/CTX109556
using the following commands:

From Command Line Interface

1. Run the following command to add the DNS name server entries to the NetScaler appliance:
   add dns nameServer <Name_Serve_IP_Address>
2. Run the following command to add the DNS suffix, such as example.com, to be used for all host queries:
   add dns suffix <DNS_Suffix>

I have opened port 53(UDP) between Netscalers and name server but still effective state was showing as down and also unable to resolve hostnames.

Solution:

Netscaler was looking for ICMP echo/reply from Name server and hence it was showing the effective state as down.

I enabled the ICMP between Netscalers and Names servers and after that the effective state has changed to UP. Now I am able to resolve DNS host names.


Have a nice Day!