IS IS Troubleshooting Overview
Table of Contents
Introduction
This page is related to common ISIS issue and potential causes.
Adjacency Problems
No Adj
- Potential issues:
- Physical Link issues
- ISIS interface configuration
- Level Mismatch
- Incorrect Subnet (I was not able to reproduce subnet issue, maybe other versions).
- Duplicate system ID
- Details of Level Mismatch
- Details of Duplicate System ID
INIT State
- Potential issues:
- MTU mismatch
- Authentication
- Transmitted Hellos are not getting to the neighbor.
Neighbor Adj but using ES-IS Protocol type
- Potential issues:
- MTU mismatch
- Authentication
- Receiving Hellos are not getting to the neighbor, either corrupted of filtered.