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MPLS: CEF brings down Protocol on Serial port

I am running IOS 12.2(3) on a Cisco 7206VXR and am trying to begin the steps to an MPLS core.

When I enable cef globally, however, the router periodically (no recognizable pattern) drops the protocol on all my frame serial ports on the router.

The outage period ranges from 1 minute to 13 minutes before the ports "magically" come back.

When I disable cef, all is well.

Has anyone seen this before? Can you shed light on the solution?

New Member

Re: MPLS: CEF brings down Protocol on Serial port

here are some IOS commands that you might find usefull. If there is a (config) command in the list, than the next listed command will be enabled by it.

to check wether cef is operational:

show ip cef summary

check if cef is operational on linecards:

show cef line

clear cef commands:

clear cef line ?

check ipc for cef:

show ipc ?

check interfaces:

show cef int

check fib:

show ip cef (+detail for adjanencies)

check layer 2 rewrites:

show ip arp (ip address)

show adjancency internal | begin (ip address)

check cef load balancing:

sh ip cef internal

cef loadbalancing packet accounting:

(config)ip cef accounting load-balance-hash

cef traffic statistics:

sho cef line

sho cef int stat

sho cef int (interface) Y

sh int (interface) stat

(config)ip cef traffic-statistics ?

cef accounting:

(config) ip cef accounting ?

sh cef not-cef-switched

sh cef drop

troubleshoot cef table:

(config)ip cef table ?

sho ip cef events

sho ip cef events trace

sho ip cef events summ

(config)ip cef table ?

show ip cef inconsistency records detail

CEF bug???

show ip cef

exec all show ip cef

show ip cef inc rec detail

exec slot show ip cef inc rec detail

show tech cef

last option:

debug ip cef ?

clear cef linecard

clear ip route

clear ip cef inconsistency

contact TAC

last resort: upgrade code?

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