[c-nsp] Clearing CEF entry (routing loop)

[Ihsan Junaidi Ibrahim]

On Thu, 27 Oct 2005 14:24:12 +0800, Oliver Boehmer (oboehmer)  
<oboehmer at cisco.com> wrote:

> Ihsan Junaidi Ibrahim <> wrote on Thursday, October 27, 2005 6:40 AM:
>
>> A routing loop has occurred in my network. I have 2 routers, R1 and
>> R2 in which R2 is connected directly to R1 and R1 to our core
>> network. Checking my routing table in both routers, the prefix is
>> being forwarded to transit provider T1 however the CEF entry is
>> pointing to another router, R3 connected to another transit provider
>> T2. My CEF entry at R1 is pointing to R2 as the next hop however at
>> R2, the next hop entry is pointing to R1 because R3 is accessible
>> only via R1. So the packets are stuck in a perpetual loop.
>>
>> I did try variations of clear ip cef commands such as
>> "clear ip cef xxx.xxx.xxx.xxx/18 prefix-statistics"
>> "clear ip cef xxx.xxx.xxx.xxx 255.255.192.0 prefix-statistics"
>>
>> but still no avail. The CEF entry for that particular route still
>> points to R3.
>
> "clear ip route xxx.xxx.xxx.xxx 255.255.192.0" should fix this as it
> causes a new CEF entry to be created.
> Another chance could be "clear ip cef epoch" (depends on Release you are
> using) which rebuilds the CEF tables.
>
> 	oli
I've tried clearing the route table but still, to no avail. The version  
information still has not changed. Before I try, what are the chances  
doing a "clear ip cef epoch" on an internet-facing router (full routes)?


-- 
Thank you for your time,
Ihsan Junaidi Ibrahim