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Juha_107583's avatar
Juha_107583
Icon for Nimbostratus rankNimbostratus
Jul 24, 2013

What causes IF-MIB::ifIndex to change?

Hi,

 

We're doing interface monitoring (F5 LTM 1600 Version 10.2.4) based on the IF-MIB::ifIndex, but the problem is that we've noticed that the index is changing. I would need to know what causes the ifIndex to change so it can be taken into consideration on the monitoring host.

 

I have tested that rebooting the LTM does not change the ifIndex. I also tested restoring configs from ucs file (b config install ) and that did not change the ifIndex either.

 

Currently on one of the LTM the interface numbers are going from 1-5 and 12-16 and originally it was continuous from 1-10 and that caused the monitoring to fail(The monitoring host is unable to map interface name / index using snmpwalk so the OID needs to be "hadrcoded").

 

IF-MIB::ifIndex.1 = INTEGER: 1

 

IF-MIB::ifIndex.2 = INTEGER: 2

 

IF-MIB::ifIndex.3 = INTEGER: 3

 

IF-MIB::ifIndex.4 = INTEGER: 4

 

IF-MIB::ifIndex.5 = INTEGER: 5

 

IF-MIB::ifIndex.12 = INTEGER: 12

 

IF-MIB::ifIndex.13 = INTEGER: 13

 

IF-MIB::ifIndex.14 = INTEGER: 14

 

IF-MIB::ifIndex.15 = INTEGER: 15

 

IF-MIB::ifIndex.16 = INTEGER: 16

 

I would need to get documentation/reference for when the ifIndex will change so we can then manually update the OID in the monitoring host.

 

Thanks!

 

management
monitoring

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  • nitass's avatar
    nitass
    Icon for Employee rankEmployee
    Jul 25, 2013
    When certain BIG-IP processes, such as mcpd or tmm restart, the mapping between the interface names and interface index values on the host changessol9432: The radvd process generates error messages when the interface index (ifIndex) values change

     

    https://support.f5.com/kb/en-us/solutions/public/9000/400/sol9432.html

     

     

    there is request for enhancement which has not yet been implemented.

     

     

    ID249120 - [RFE] stable Linux ifindexes for VLANs across configuration reloads and restarts