ifIndex 0 - problem

Hello,

I have inherited a management system that is barfing on some cisco

72xx and 76xx routers when it finds an ifIndex = 0, rather than ifIndex =1 or 10. I gather that ifIndex =0 is not allowed, but I am not sure by who or what - so I dont know if it is reasonable for the NMS to ignore ifIndex = 0 or not. Nor do I know how the indexes got set to 0 in the ist place, nor hwta the fix might be (to make all indexes 1 or more. Can someone hep me out?

TIA

Tony

Reply to
kbloomfield
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As I understand it IF indices are set at boot time automatically and in principle can be re-calculated at any time thereafter. e.g. if a card is inserted.

More recent IOS is much better behaved regarding IF indices and does a better job of maintaining consistent mapping between indices and interfaces.

It would be surprising if cisco had done anything that deviated from the standard. Very surprising.

I don't think that it is possible to manually choose IF indices.

You can check the IF indices for a device yourself by using getif.exe and browsing to =2Eiso.org.dod.internet.mgmt.mib-2.interfaces.ifTable.ifEntry.ifIndex

formatting link
Its old code and has limitations but the basics work well. Its the only free mib browser that I know of.

Reply to
Bod43

Thanks for your reply. After some digging with a mib-browser along the lines you suggest I confirm you are right about the ifIndex being correct. The problem it seems is ipAdEntIfIndex. On each of .routers that generates a problem message, when interogated by the management system, there is a ipAdEntIfIndex =3D0. I had a look at the IP-MIB and IF-MIB and I think that there should not be an ipAdEntIfIndex =3D0. unless there is an ifIndex =3D0 (which there is not and that wouldbe wrong anyway). But I am not sure.

Can anyone clarify this,plz?

TIA

Kevin

Reply to
kbloomfield

Newer versions of IOS allow one to display the SNMP ifindex values

HUB#show snmp mib ifmib ifIndex

Ethernet0/0: Ifindex = 1 Loopback0: Ifindex = 5 Null0: Ifindex = 4 VoIP-Null0: Ifindex = 3 FastEthernet1/0: Ifindex = 2 Loopback999: Ifindex = 6

You can check the Ifindex values displayed against the Ifindex values being received by NMS system

Reply to
Merv

Thanks Merv,

Probably it was not clear in my posting but it is the ipAdEntIfIndex which are wrong ie there are ipAdEntIfIndex=0 returned by an snmpwalk. The ifIndexes are fine - they start from 1..

Kevin

Reply to
kbloomfield

allow one to display the SNMP ifindex values

Time to give the Cisco TAC a call

Reply to
Merv

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