Pattern 'Netscaler load balancer' does not update dscy_route_interface.cmdb_ci field, which it should as per the below documentation.
https://docs.servicenow.com/csh?topicname=c_LoadBalancerCitrixNetscaler.html&version=latest#c_LoadBalancerCitrixNetscaler

1. Run discovery against a netscaler load balancer
2. Navigate to 'dscy_router_interface' table which shows CI field is not populated by Netscaler load balancer pattern.

Modify step in Netscaler load balancer pattern:

53.4 Ref/Rel between Interface and Netscaler

Resolution: Direction of the reference between tables cmdb_ci_lb_netscaler to dscy_router_interface should be changed from 'parent to child' to 'child to parent' as per metadata hosting rule.