Velocity Reviews - Computer Hardware Reviews

Velocity Reviews > Newsgroups > Computing > Cisco > How to see frag/defrag utilization of the router.

Reply
Thread Tools

How to see frag/defrag utilization of the router.

 
 
AM
Guest
Posts: n/a
 
      11-25-2005
I would know how to see whether the router is busy on
defragmentin/fragmenting of packets about wrong settings of MTU.
I have IPsec traffic going through the router and when it is present the CPU
blasts up to 100%. Every other traffic can reach peaks of 400-500 kbytes per
second while the IPsec traffic only 30/40 kBytes per second.
Using "cpu show proc" the sum of all processes is close to 1% while the
percentage on the top of list reaches 95/100%.

Many thanks,

Alex.


 
Reply With Quote
 
 
 
 
Igor Mamuzic
Guest
Posts: n/a
 
      11-26-2005
Hi,

You can use 'show ip traffic' command to check for frags/defrags among the
other things... 'debug ip traffic' is also valuable, but limit it with ACL
or use it at low utilization day periods...

When 'sh proc cpu' indicates high cpu percentage, but sum of all processes
does not reach that cpu percentage (in your case 95/100%) then this means
that your cpu is busy because of high number of interrupts.
Make sure that your router has CEF switching enabled: 'show ip int' and then
look for the "IP CEF switching is enabled" or similar.
Next, if you suspect IPSec traffic for this issue, check if your router is
equipped with AIM-VPN card or it's on board variant and if so, type 'sh
crypto engine accelerator statistic' to check if AIM-VPN card is making it's
purpose.
If all from the above is ok, then consult the following URL:
http://www.cisco.com/en/US/products/...otes_list.html
and look for "Troubleshooting high CPU utilization" links...

B.R.
Igor






"AM" <(E-Mail Removed)> wrote in message
newsRGhf.6202$(E-Mail Removed)...
>I would know how to see whether the router is busy on
> defragmentin/fragmenting of packets about wrong settings of MTU.
> I have IPsec traffic going through the router and when it is present the
> CPU
> blasts up to 100%. Every other traffic can reach peaks of 400-500 kbytes
> per
> second while the IPsec traffic only 30/40 kBytes per second.
> Using "cpu show proc" the sum of all processes is close to 1% while the
> percentage on the top of list reaches 95/100%.
>
> Many thanks,
>
> Alex.
>
>



 
Reply With Quote
 
 
 
 
Hansang Bae
Guest
Posts: n/a
 
      11-26-2005
AM wrote:

> I would know how to see whether the router is busy on
> defragmentin/fragmenting of packets about wrong settings of MTU.
> I have IPsec traffic going through the router and when it is present
> the CPU blasts up to 100%. Every other traffic can reach peaks of
> 400-500 kbytes per second while the IPsec traffic only 30/40 kBytes
> per second. Using "cpu show proc" the sum of all processes is close
> to 1% while the percentage on the top of list reaches 95/100%.



Is your IPSec traffic going through serial interfaces? If so, just
crank the physical mtu to 1600 on both side. "sho ip traffic" will
tell you how many packets you are fragmenting.

--

hsb


"Somehow I imagined this experience would be more rewarding" Calvin
**************************ROT13 MY ADDRESS*************************
Due to the volume of email that I receive, I may not not be able to
reply to emails sent to my account. Please post a followup instead.
************************************************** ******************
 
Reply With Quote
 
 
 
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Memory utilization for Windows services Jay Kavimandan ASP .Net 1 11-02-2004 11:41 AM
Low memory utilization sort? pt Perl 1 06-04-2004 11:09 AM
Stats on bandwidth utilization by port needed 1 Cisco 2 12-13-2003 06:46 AM
2600XM, Frame Relay, and High CPU Utilization Donald Zelenak Jr. Cisco 5 12-06-2003 01:18 AM
High utilization on network with Cisco 4500M LAN Interface Sarah Cisco 3 12-01-2003 10:09 PM



Advertisments