Troubleshoot IP Name-Server Command Not Pushed to IOS® XE Catalyst SD-WAN Device

Introduction

This document describes the issue reported as Cisco bug ID CSCwj12763 , where the IP name-server command was not successfully pushed to Cisco IOS® XE Catalyst SD-WAN devices. 

Affected Products

• Cisco IOS® XE Catalyst SD-WAN devices  Release 17.12.1 or older
• Cisco Catalyst SD-WAN Manager Release 20.12.1 and newer

Problem Description

Users reported that the IP name-server command is not being applied to devices when pushed from the SD-WAN Manager.

This can lead to potential DNS resolution issues impacting network functionality. The issue is particularly relevant when using Cisco Catalyst SD-WAN Manager Release 20.12.1 with devices running Cisco IOS® XE Catalyst SD-WAN Release 17.11.1a or earlier. This is a documentation bug, not a software defect.

This manifests in two primary ways:

1. When configuring the command with a VRF, the device returns an error: Device: "Data provider returned CONFD_ERRCODE_INCONSISTENT_VALUE (38): inconsistent value: Device refused one or more commands: ip name-server vrf 1 ^ % Invalid input detected at '^' marker."
2. When configuring the command without a VRF (example., ip name-server 10.1.1.1 10.0.0.1), no errors are reported, but the configuration is not applied on the device.

Conditions

This issue occurs when running SD-WAN Manager version 20.12 with any Cisco IOS® XE device version 17.12 (example, 17.9.3) or older.

Root Cause Analysis

The root cause is related to a discrepancy in the documented command syntax within the Cisco IOS® XE documentation. The SD-WAN Manager is utilizing the correct command syntax, but older IOS® XE versions do not support it as described.

Resolution

There is no software patch required. The resolution involves utilizing the correct command syntax as outlined in the Cisco documentation.

Workaround:

Apply via CLI add-on feature or CLI decice templates:

• For VRF configurations (Issue 1): Edit the CLI template to include the “server-ip-list” keyword: ip name-server vrf <name> server-ip-list <list of servers IPs>
• For Global configurations (Issue 2): Edit the CLI template to include the “no-vrf” keyword: ip name-server no-vrf <list of servers>

Alternatively, use feature-based configuration templates or configuraiton groups.

Usage Guidelines:

For detailed usage guidelines regarding the ip name-server command, refer to the Cisco IOS® XE documentation: https://www.cisco.com/c/en/us/td/docs/routers/sdwan/command/iosxe/qualified-cli-command-reference-guide/m-ip-commands.html#GUID-6A2D4E93-B995-4FA1-BA10-E7CA3C7EE977

Verification Steps:

After applying the workaround, verify the DNS configuration by:

1. Logging into the SD-WAN device via CLI.
2. Executing the command: show running-config | include name-server
3. Executing the command: show sdwan running-config | include name-server
4. Confirming that the configured IP name-server addresses are displayed correctly.

Additional Information:

For further assistance or to report any ongoing issues, please refer to the Cisco Support website: https://www.cisco.com/c/en/us/td/docs/routers/sdwan/command/iosxe/qualified-cli-command-reference-guide/m-ip-commands.html#GUID-6A2D4E93-B995-4FA1-BA10-E7CA3C7EE977

Disclaimer:

This article provides information regarding a known issue and its resolution. Cisco is not responsible for any issues arising from improper implementation of the recommended solutions. Always consult with qualified network engineers before making changes to your network configuration.