Reg.CPU utilization problem

[anilsiri]

Hai,

I have a setup where 5 VLANs are being terminated on FastEthernet interface of my router by configuring sub-interfaces on it. Do I need to enable "ip route-cache" on the interfaces b'coz my router's CPU Util is reaching 99% and the interface has input queue drops. Can anyone suggest me what to do? This is interface is terminated on switch with full-duplex on both ends.

Thanks,
Anil

 

[gconnect]

that enables fast switching which can indeed help, but for cpu reaching 99%, i don't know if that will solve the root of all your issues

are you sure that someone didn't telnet/ssh in in the past and turn on a debugging process that may still be running in the background?

do a 'show process' and a 'show process cpu' to see what process is zapping the most from your router

what model router? also how much memory? during these times of high cpu utilization, what is the rx and tx load on the interfaces?

and also:

http://www.cisco.com/en/US/products/sw/iosswrel/ps1828/products_tech_note09186a00800a70f2.shtml

 

[anilsiri]

Router Model is
cisco 3640 (R4700) processor (revision 0x00) with 60416K/5120K bytes of memory.

When "show processes cpu" is issued I observed "IP Input" process to be taking much of the CPU's time. We tried with enabling "ip route-cache same-interface" on FE3/0 which is the main interface under which sub-interfaces were created.
Fe3/0.1 (VLAN 1 native for users)
Fe3/0.2 (VLAN 6 for users)
Fe3/0.3 (VLAN 32 for servers)
Fe3/0.4 (VLAN 35 for NTservers)
Fe3/0.5 (VLAN 40 for Test servers)

When that option is enabled, the users in VLAN 6 were able to talk to servers in all the other VLANs(32,35,40) but no communication with users in VLAN 1. ANd VLAN1 is completely blocked.

Where am I doing mistake? Any extra settings are to be done on VLAN 1.

Please guide me.

Thanks,
Anil

 

[gconnect]

did the cpu utilization go down when issueing the 'ip route-cache same-interface command?

what model switch? are you using STP on the switches?
check the status of the interface and vlan 1

switch-1#show int fastEthernet 0/1 switchport
Name: Fa0/1
Switchport: Enabled
Administrative mode: trunk
Operational Mode: trunk
Administrative Trunking Encapsulation: isl
Operational Trunking Encapsulation: isl
Negotiation of Trunking: Disabled
Access Mode VLAN: 0 ((Inactive))
Trunking Native Mode VLAN: 1 (default)
Trunking VLANs Enabled: ALL *******************does yours say this
Trunking VLANs Active: 1,2,3 ********************does yours have vlan1 here
Pruning VLANs Enabled: 2-1001

also do a
'show vlan' on the switch
does vlan 1 appear in the 'active' state

can any users from vlan1 ping the immediately connected router interface?



i do not have your router and switch configurations so i will provide a working example in a link that you may compare against yours

http://www.cisco.com/en/US/tech/tk3...figuration_example09186a00800949fd.shtml#2600

 

[anilsiri]

Yes it went down after issuing "ip route-cache" command

cisco WS-C3548-XL-EN switch

Yes STP is enabled.

sh int f0/16 switchport
Name: Fa0/16
Switchport: Enabled
Administrative mode: trunk
Operational Mode: trunk
Administrative Trunking Encapsulation: dot1q
Operational Trunking Encapsulation: dot1q
Negotiation of Trunking: Disabled
Access Mode VLAN: 0 ((Inactive))
Trunking Native Mode VLAN: 1 (default)
Trunking VLANs Enabled: ALL
Trunking VLANs Active: 1,6,32,35,40,99,100
Pruning VLANs Enabled: 2-1001

Priority for untagged frames: 0
Override vlan tag priority: FALSE
Voice VLAN: none
Appliance trust: none


Yes VLAN 1 is active in the list.

Yes the users from VLAN 1 were able to ping to immediately connected router interface.

 

[gconnect]

you should post the configs

 

[wybnormal]

VLAN1 is the management VLAN by default. So try this:

!
interface VLAN1
ip address 172.20.128.179 255.255.255.0
no ip route-cache
!
interface FastEthernet0/1
switchport mode trunk

Notice the "no ip route-cache" is not on the interface, it's on the VLAN

See this:

http://www.cisco.com/en/US/products...figuration_guide_chapter09186a008007da42.html

Also, this is an unsupported command on the 3550s.

http://www.cisco.com/en/US/products...figuration_guide_chapter09186a008007e773.html

MikeS

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