Knob for Ping and Traceroute with VRF to Choose Global DNS Server

This feature provides a knob for ping and trace route with VRF to choose global DNS server when no DNS servers are defined in a VRF. This module explains how to configure Knob for Ping and Traceroute with VRF to choose Global DNS Server.

Prerequisites for Knob for Ping and Traceroute with VRF to Choose Global DNS Server

  • VRF must be configured.

Information About Knob for Ping and Traceroute with VRF to Choose Global DNS Server

Overview of Knob for Ping and Traceroute with VRF to Choose Global DNS Server

Prior to the Knob for Ping and Traceroute with VRF to choose Global DNS Server feature, ping or traceroute in VRF would look up only in the specified name server to resolve the domain name. If DNS server is specified in the VRF, the DNS is used to resolve the domain name. If DNS server is not specified in the VRF, the DNS fails to resolve the domain name.

With the implementation of the Knob for Ping and Traceroute with VRF to choose Global DNS Server feature, ping and traceroute uses VRF DNS server (if the server is already configured in a VRF), otherwise global DNS server is used to resolve the domain name. The ip global-nameserver command acts as a knob that facilitates the ping and traceroute to use the VRF DNS server or the global DNS server when the server is not configured in a VRF.

../topics/How to Configure Knob for Ping and Traceroute with VRF to Choose Global DNS Server

Configuring a Knob for Ping and Traceroute with VRF to Choose Global DNS Server

SUMMARY STEPS

  1. enable
  2. configure terminal
  3. ip global-nameserver
  4. exit

DETAILED STEPS

  Command or Action Purpose

Step 1

enable

Example:


Device> enable

Enables privileged EXEC mode.

  • Enter your password if prompted.

Step 2

configure terminal

Example:


Device# configure terminal

Enters global configuration mode.

Step 3

ip global-nameserver

Example:


Device(config)# ip global-nameserver

Configures a knob for ping and traceroute to use VRF DNS server for resolving the domain name.

Step 4

exit

Example:


Device(config)# exit

Exits global configuration mode.

../topics/Configuration Examples for Knob for Ping and Traceroute with VRF to Choose Global DNS Server

Example: Knob for Ping and Traceroute with VRF to Choose Global DNS Server 


Device> enable
Device# configure terminal
Device(config)# ip global-nameserver
Device(config)# exit

Additional References for Knob for Ping and Traceroute with VRF to Choose Global DNS Server

Related Documents

Related Topic

Document Title

Multitopology Routing (MTR) commands

Cisco IOS Multitopology Routing Command Reference

MTR in VRF

Multitopology Routing Configuration Guide

Technical Assistance

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Feature Information for Knob for Ping and Traceroute with VRF to Choose Global DNS Server

The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.

Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.
Table 1. Feature Information for Knob for Ping and Traceroute with VRF to Choose Global DNS Server

Feature Name

Releases

Feature Information

Knob for Ping and Traceroute with VRF to Choose Global DNS Server

Cisco IOS XE Release 3.12S

This feature provides a knob for ping and trace route with VRF to choose global DNS server when no DNS servers are defined in a VRF.

The following commands were introduced or modified: ip global-nameserver .