07-16-2008 01:54 AM - edited 03-03-2019 10:44 PM
Hi,
I am having a Router connected to Internet with Public IPs. Since last week I am receiving Alerts from my HPOV Server regarding High CPU Utilization in Cisco 1760 Router. Pls help what could be the reason. IOS is 12.3. While troubleshooting, Show Process CPU is showing that 'IP Input' is taking max. CPU
Solved! Go to Solution.
07-16-2008 03:19 AM
The CPU load looks normal.
You are not opening any Security Hole by enabling IP CEF Cache.
07-16-2008 02:09 AM
Hello,
you need to verify if there a lot of packets that are process switched instead of being switched by CEF of fast switching.
Process switched packets require more CPU resources.
Try with the sh ip cef and look for the counters of packets not processed by CEF
May be your router is under attack and is receiving packets that have ip options in header that are process switched because you have public ip addresses on it
Hope to help
Giuseppe
07-16-2008 02:22 AM
Pls find below the output of "Show IP Cef" from which i am not able to understand anything.
Prefix Next Hop Interface
0.0.0.0/0 attached Serial1/0
0.0.0.0/32 receive
69.165.235.104/30 attached Serial1/0
69.165.235.104/32 receive
69.165.235.106/32 receive
69.165.235.107/32 receive
69.165.235.144/28 attached FastEthernet0/0
69.165.235.144/32 receive
69.165.235.145/32 receive
69.165.235.146/32 69.165.235.146 FastEthernet0/0
69.165.235.147/32 69.165.235.147 FastEthernet0/0
69.165.235.148/32 69.165.235.148 FastEthernet0/0
69.165.235.150/32 69.165.235.146 FastEthernet0/0
69.165.235.156/32 69.165.235.146 FastEthernet0/0
69.165.235.169/32 receive
172.17.0.0/16 69.165.235.146 FastEthernet0/0
172.18.0.0/16 69.165.235.146 FastEthernet0/0
224.0.0.0/4 drop
224.0.0.0/24 receive
255.255.255.255/32 receive
Pls help.
07-16-2008 02:24 AM
show the configuration
07-16-2008 02:32 AM
07-16-2008 02:40 AM
try to enable CEF
interface FastEthernet0/0
ip route-cache cef
ip route-cache
!
interface Serial1/0
ip route-cache cef
ip route-cache
and show the output
sh int f0/0
sh int s1/0
07-16-2008 02:54 AM
07-16-2008 03:02 AM
could you show the output
"sh proc cpu sort 5min" or
"sh proc cpu | e 0\.00"
07-16-2008 03:11 AM
Pls find below the output
**********************************
sh proc cpu | exclude 0.0
CPU utilization for five seconds: 12%/8%; one minute: 12%; five minutes: 8%
PID Runtime(ms) Invoked uSecs 5Sec 1Min 5Min TTY Process
42 653733451 757247646 863 2.12% 1.53% 1.11% 0 IP Input
108 1839 3142 585 1.14% 0.50% 0.32% 6 Virtual Exec
**********************************
Hope by enabling IP CEF Cache, we are not opening any Security Hole.
07-16-2008 03:19 AM
The CPU load looks normal.
You are not opening any Security Hole by enabling IP CEF Cache.
07-16-2008 11:04 PM
May i know in which case we should run the CEF
07-17-2008 01:12 AM
In any case, and it's the default.
07-17-2008 01:09 AM
Thanx Dear. Till now I have not received alert. Hope the problem is resolved now.
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