871 interface config question

[willemvwyk]

Hello

I currently have a Cisco 871 router. When I configure the WAN interface with no ip route-cache the router adds no ip route-cache cef in automatically??

Does anyone know why? Below is the output:

With ip route-cache & ip route-cache cef

========================================

router1#sh run int f4

Building configuration...

Current configuration : 113 bytes

!

interface FastEthernet4

ip address 95.95.95.3 255.255.255.0

no ip mroute-cache

duplex auto

speed auto

end

router1#

Then disable ip route-cache

===========================

router1#conf t

Enter configuration commands, one per line. End with CNTL/Z.

router1(config)#int f4

router1(config-if)#no ip rou

router1(config-if)#no ip route-cache

router1(config-if)#^Z

router1#sh run int f4

Building configuration...

Current configuration : 155 bytes

!

interface FastEthernet4

ip address 95.95.95.3 255.255.255.0

no ip route-cache cef

no ip route-cache

no ip mroute-cache

duplex auto

speed auto

end

As can be seen above the cef is included. Yet when checking my router config it shows I have cef enabled on the router.

router1#sh run | i cef

ip cef

Can someone please explain what I am missing?

Thanks

willemvw

[tomocisco]

Hi Willemvw,

From the output of your sho run above I can see you used 'no ip route-cache cef'.

If your interest is to disable ip cef, use 'no ip cef'.

How ever when you disable ip cef, 'ip verify unicast reverse-path' is also removed (if configured).

I think this feature or behavior has to do with the ios version.

Cheers.

Tom

[willemvwyk]

Hi Tom

Can you please point out where I used 'no ip route-cache cef'?

To my knowledge I need to type in 'no ip route-cache cef' in order to disable it, yet I have not typed that in.

Thanks for your help :)

regards

willemvw

[paolo bevilacqua]

Why do do want to disable ip route-cache (that is not the default anymore since years) anyway ?

[willemvwyk]

Hi Paolo

Thanks for the reply. When did this stop becoming the default?

I am disabling ip route-cache purely from a configuration point of view. I am setting up 2 routers to use ezvpn and the config I am using requires no ip route-cache.

I will be posting some ezvpn questions later on the forum

Regards

willemvw

[paolo bevilacqua]

I think CEF became default about 8 years ago.

Please post a reference about what makes you believe you need to disable route-cache for EzVPN.