07-03-2004 03:55 AM - edited 03-02-2019 04:48 PM
I recently configured several 3725 routers with the IP CEF command. When installed, trafffic slowed dramatically, with packets dropping everywhere between these routers.
Immediately the command was removed, traffic returned to normal.
Does anyone have any knowledge of the workings and effects of utilising IP CEF?
Many thanks in advance
07-03-2004 04:49 AM
Hello,
which IOS version are you running ? Can you post your configuration(s) ?
Regards,
Georg
07-03-2004 05:36 AM
Hello Georg
Config as follows: -
version 12.3
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname xxxxxxxxxxx
!
boot-start-marker
boot-end-marker
!
enable secret xxxxxxxxxxxxxxxxxxxxxxxx
!
clock summer-time BST recurring last Sun Mar 2:00 last Sun Oct 2:00
no aaa new-model
ip subnet-zero
!
!
!
ip domain name xxxxxxxx
ip name-server xxxxxxxx
ip name-server xxxxxxxx
no ftp-server write-enable
!
!
!
!
interface FastEthernet0/0
description **PSN switch Clarence Crt**
ip address xxxxxxxx 255.255.255.252
duplex auto
speed auto
!
interface Serial0/0
description **Link to Eliz House**
bandwidth 2048
ip address xxxxxxxx 255.255.255.252
no ip mroute-cache
no fair-queue
!
interface FastEthernet0/1
description **100Mb LES circuit to Queens Crt**
ip address xxxxxxxx 255.255.255.252
speed 100
full-duplex
!
interface Serial0/1
description **Link to lincoln Bldgs**
bandwidth 2048
ip address xxxxxxxx 255.255.255.252
!
interface FastEthernet1/0
description ***100Mb LES circuit Causeway***
ip address xxxxxxxx 255.255.255.252
speed 100
full-duplex
!
interface FastEthernet1/1
description ***10Mb LES circuit VicHall***
ip address xxxxxxxx 255.255.255.252
speed 10
half-duplex
!
router ospf 100
log-adjacency-changes
network xxxxxxxx 0.0.0.0 area 0.0.0.0
network xxxxxxxx 0.0.0.0 area 0.0.0.0
network xxxxxxxx 0.0.0.0 area 0.0.0.0
network xxxxxxxx 0.0.0.0 area 0.0.0.0
network xxxxxxxx 0.0.0.0 area 0.0.0.0
network xxxxxxxx 0.0.0.0 area 0.0.0.0
!
ip classless
xxxxxxxx
xxxxxxxx
xxxxxxxx
xxxxxxxx
xxxxxxxx
no ip http server
!
snmp-server community xxxxxxxx
snmp-server enable traps tty
!
line con 0
password xxxxxxxx
login
line aux 0
password xxxxxxxx
login
line vty 0 4
password xxxxxxxx
login
!
ntp clock-period 17180696
ntp source FastEthernet0/0
ntp server xxxxxxxx
!
end
thanks
07-03-2004 05:55 AM
Hello,
your config looks ok, I also could not find any CEF-related bugs. Is there a specific reasons why you only advertise host addresses in your OSPF, while your interfaces have /30 subnets ? Can you try and advertise the networks:
network xxxxxxxx 0.0.0.3 area 0.0.0.0
network xxxxxxxx 0.0.0.3 area 0.0.0.0
network xxxxxxxx 0.0.0.3 area 0.0.0.0
network xxxxxxxx 0.0.0.3 area 0.0.0.0
network xxxxxxxx 0.0.0.3 area 0.0.0.0
network xxxxxxxx 0.0.0.3 area 0.0.0.0
and then turn on CEF ?
Regards,
Georg
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