03-23-2010 07:59 AM - edited 03-06-2019 10:16 AM
Ladies/Gents,
Forgive me since this seems to be a grossly incompetent question. I have been scouring cisco support and cannot find out what the deault
is for IP CEF on cat switch hardware (i.e. 35xx, 29xx, 37xx, 45xx and 65xx).
Is CEF only applicable on a MLS with "ip routing" enabled?
If someone could school me on this and also point to the body of literature it would be greatly appreciated.
James A. Abercromby II
732.614.9684
03-23-2010 08:54 AM
Hey James,
Not an incompetent question at all.
Well, what you wrote above was absolutely true (I am still trying to rake up documentation for the same), however CEF is enabled on layer 3 switches with IP Routing enabled only. And if I recollect correctly, you cannot turn it off (like on router platforms).
I distinctly remember having encountered this, if you try and enable CEF with IP routing disabled, the switch throws up an error message which explicitly asks you to enable IP routing first.
Would post you the doc as soon as I find one.
Thanks
Pronoy
02-15-2012 12:02 PM
It seems to depend on the switch model:
For a Cisco 3560v2 switch running:
Cisco IOS Software, C3560 Software (C3560-IPBASEK9-M), Version 12.2(58)SE1
Model number : WS-C3560V2-48TS-S
A-05-38-S-01#sh cef state
CEF Status:
RP instance
common CEF disabled
IPv4 CEF Status:
CEF disabled/not running
dCEF disabled/not running
CEF switching disabled/not running
universal per-destination load sharing algorithm, id 8464B72F
IPv6 CEF Status:
CEF disabled/not running
dCEF disabled/not running
universal per-destination load sharing algorithm, id 8464B72F
When you run the command:
Test-Switch(config)#ip cef distributed
%Must enable ip routing first
For a Cisco 3750v2 switch running:
Cisco IOS Software, C3750 Software (C3750-IPBASEK9-M), Version 12.2(58)SE2, RELEASE SOFTWARE (fc1)
Model number : WS-C3750V2-48TS-S
A-08-25-S-01#sh cef stat
CEF Status:
RP instance
common CEF enabled
IPv4 CEF Status:
CEF enabled/running
dCEF enabled/running
CEF switching enabled/running
universal per-destination load sharing algorithm, id 400EC381
IPv6 CEF Status:
CEF disabled/not running
dCEF disabled/not running
universal per-destination load sharing algorithm, id 400EC381
On Cisco 3750v2 switches, cef is enabled by default …
02-15-2012 02:19 PM
Yes routing has to be turned on in order to use CEF on the 3560.
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