snmp traps

Unanswered Question
Oct 26th, 2007

I am trying to figure out the best way to configure alerts for 7609 router such that when interface pos9/0/0.1 is down I will be notified.

the router is currently configured "snmp-server enable traps snmp authentication linkdown linkup coldstart warmstart". but when the sub interface went down, no alert was sent. in this case I think because of couple reasons.

1. the physical interface remain "up" but protocol "down".

2. the interface command "snmp trap link-status" is not configured on either the physical or sub interface. this command is not applicable to sub interface. even if it were configured on the physical interface, because the link didn't go down (only protocol down) there wouldn't be traps.

How should configure the router? Do I have to rely on other notification options such as maybe bgp neighbor loss? Please advise.

POS9/0/0 unassigned YES manual up down

POS9/0/0.1 YES manual down down

I have this problem too.
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Pushkar Sambhoos Fri, 10/26/2007 - 22:26

The easiest way to generate the SNMP trap would be to use the RMON feature. The configuration wouldbe something as shown below.

1. Find the ifIndex of the subinterface using any of the standard snmp tools.

2. Configure an RMON event to generate a traps and the description in the trap.

rmon event 1 description "POS9/0/0.1 link up" trap public

rmon event 2 description "POS9/0/0.1 link down" trap public

3. Configure an RMON alarm to associate the events with the ifOperStatus for the pos interface/subinterface.

The possible values can be obtained from the SNMP object navigator available at

1 : up

2 : down

The assumptions are

The pos0/0/0.1 interface ifIndex is 100

The interface is being monitored every 30 secs

rmon alarm 1 30 absolute rising-threshold 1 1 falling-threshold 2 2

4. Configure SNMP appropriately to generate the traps

snmp-server community public

snmp-server enable traps

snmp-server host public

This should generate the traps as you want them to be generated.

You can find more information on RMON configuration at

-- Pushkar


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