Network Management
NPM Topology Link not displayed due to the Sysname and DeviceID mismatch
It possible that sometimes Topology link won't be displayed within the maps or the Web Console due to the sysname and DeviceID mismatch and for Topology connection to work, overall Sysname and DeviceID has to be the same.
First published date
9/13/2019 11:11 AM
Last published date
9/13/2019 11:55 AM
Overview
To be able to calculate connections from CDP data topology has to find two matches. First one is IP address match. Second match is Sysname (DeviceID) and sometimes there might be an issue with the second match and because of that topology link is not available.
So there is different format of names and for topology to be able to map it has to have it in same format.
An example:
For npm nodes we are poll sysname under OID 1.3.6.1.2.1.1.5.0 (http://oidref.com/1.3.6.1.2.1.1.5)
In walk is sysname in this format:
.1.3.6.1.2.1.1.5.0 = STRING: "test1"
CDP data reports DeviceID, here basically is the stored name of the device where node has connection (second node). We are polling this information under OID {color:#172b4d}1.3.6.1.4.1.9.9.23.1.2.1.1.6{color} (http://oidref.com/1.3.6.1.4.1.9.9.23.1.2.1.1.6)
In walk is DeviceID for affected nodes in this format:
.1.3.6.1.4.1.9.9.23.1.2.1.1.6.83886080.12451841 = STRING: "test1.test.com(test)"
So there is mismatch and Sysname polled by SNMP returned the Sysname of the device without DNS suffix, and CDP data returned FQDN with serial number.
So there is different format of names and for topology to be able to map it has to have it in same format.
An example:
For npm nodes we are poll sysname under OID 1.3.6.1.2.1.1.5.0 (http://oidref.com/1.3.6.1.2.1.1.5)
In walk is sysname in this format:
.1.3.6.1.2.1.1.5.0 = STRING: "test1"
CDP data reports DeviceID, here basically is the stored name of the device where node has connection (second node). We are polling this information under OID {color:#172b4d}1.3.6.1.4.1.9.9.23.1.2.1.1.6{color} (http://oidref.com/1.3.6.1.4.1.9.9.23.1.2.1.1.6)
In walk is DeviceID for affected nodes in this format:
.1.3.6.1.4.1.9.9.23.1.2.1.1.6.83886080.12451841 = STRING: "test1.test.com(test)"
So there is mismatch and Sysname polled by SNMP returned the Sysname of the device without DNS suffix, and CDP data returned FQDN with serial number.
Product section
Network Performance Monitor
Cause
Sysname and DeviceId has to be same for the topology to be able to create connection and because they are not, the connection is not available.
Resolution
For resolution, please check the following:
- It should be possible to setup format of DeviceID in CDP data (here is the page where this setup is mentioned (©2019, manualslibcom, available at https://www.manualslib.com/manual/995564/Cisco-300-Series.html?page=209, obtained on September, 2019).
- For example, if you has set format of DeviceID on SerialNumber it won't work as topology can work only with hostname format. Also domain part of name should be same on both places to be able to create connection. So resolution would be to check those and make sure they are matching.