# Name Server Identifier (NSID)

Module `nsid` provides server-side support for RFC 5001 which allows DNS clients to request resolver to send back its NSID along with the reply to a DNS request. This is useful for debugging larger resolver farms (e.g. when using Multiple instances, anycast or load balancers).

NSID value can be configured in the resolver’s configuration file:

    modules.load('nsid')
    nsid.name('instance 1')

Tip

When dealing with Knot Resolver running in multiple instances managed with systemd see Instance-specific configuration.

You can also obtain configured NSID value:

    > nsid.name()
    'instance 1'

The module can be disabled at run-time:

    modules.unload('nsid')