06-12-2007 08:33 PM - edited 03-05-2019 04:40 PM
Hi everyone,
I have a question about Policy Based Routing (PBR) on MSFC.
Does MSFC1 process Policy Based Routing in software or in hardware ?
What about MSFC3 ?
The background of this question is as follows.
Our customer facing CPU utilization issue on MSFC1. The peak CPU utilization on the MSFC1 become about 30%. Hardware component of that Catalyst 6506 is as follows,
Catalyst 6506
SUP1A : CatOS 5.5(3)
MSFC1 : IOS 12.1(2)E
PFC1
The MSFC1 is configured with
8 VLAN interfaces
20 static routes (dynamic routing is not operating)
1 named ACL with 16 entries
2 numbered ACL with 50 entries each
I think above configuration does not effect CPU utilization so much. So I am doubting that PBR raises CPU utilization.
The following PBR configured on the MSFC1.
----------
route-map PBR permit 0
match ip address 111
set ip default next-hop xxx.xxx.xxx.xxx
route-map PBR permit 1
match ip address 222
set ip default next-hop yyy.yyy.yyy.yyy
----------
Now customer is thinking of upgrading the Cat6506 to Cat6504-E.
Hardware component of new Catalyst 6504-E is as follows.
Catalyst 6504-E
SUP720-3B : Cat IOS 12.2(17d)SXB11a
MSFC3
PFC3
And customer similarly uses same PBR configuration also on new Cat6504/MSFC3.
I understand I should test on both MSFC1 and MSFC3 to compare CPU utilization, however unfortunately I can not prepare those system now. So I posted it becasue I would like to know any information.
Would you please let me know MSFC1 process Policy Based Routing in software or in hardware ?, and what about MSFC3 ?
Your information would be appreciated.
Best regards,
06-12-2007 11:54 PM
Hi
I can answer at least part of your questionas i have just had to look this up myself.
PBR is supported in hardware on a 6500 by the Policy Feature Card and Distributed Forwarding Card. Certainly with a PFC3 PBR is supported in hardware with the following caveats (from Cisco doc)
=============================================
Policy-based routing (PBR) for route-map sequences that use the match ip address, set ip next-hop, and ip default next-hop PBR keywords.
=============================================
This is link to full doc for more details
AFAIK a PFC card will also support PBR in hardware with the same caveats but i could be wrong as i could find no definitive answer on the Cisco site.
Hope this has at least partially answered your question
Jon
06-13-2007 12:21 AM
Yes, I agree with Jon,
your focus shall be the PFC, and not MSFC. The Policy Feature Card (PFC) and any Distributed Feature Cards (DFCs) provide hardware support for policy-based routing (PBR) for route-map sequences that use the match ip address, set ip next-hop, and ip default next-hop PBR keywords.
Check the release notes about specific behavior of PBR (for example: on 12.2 SX PBR traffic through switching module ports where PBR is configured is routed in software if the switching module resets -> CSCee92191)
For more informations:
Another good advice is 'enable CEF' to improuve the PBR performances:
'ip cef'
Let me know
HTH
Andrea
06-13-2007 12:36 AM
Hi,
I actually agree with both Jon and Andrea, but i just have one concern, AFAIK CEF is supported in HW starting from MSFC2 and not MSFC1.
HTH,
Mohammed Mahmoud.
06-13-2007 01:13 AM
Hi Jon, Andrea and Mohammed,
Thank you very much for your reply.
I understand I should focus on PFC not MSFC. According to the following URL,
----------
Policy-Based Routing TCAM and Adjacency Utilization
In Supervisor 2 with PFC2 and Supervisor 720 with PFC3, policy-based routing (PBR) is fully supported in hardware using a combination of the security and feature ACL TCAM and the hardware adjacency table.
----------
PBR is fully supported in hardware in Supervisor 2 with PFC2 and Supervisor 720 with PFC3. So in my case that using PFC1, I think PBR might not be fully supported in hardware.
Best regards,
06-13-2007 02:06 AM
Correct, Shinichi,
I agree with Mohammed, you need at least a Sup2 MSFC2 PFC2.
HTH
Andrea
06-13-2007 05:45 PM
Hi Andrea,
Thank you very much for your reply.
I understand it and I plan to test whether PBR effect cpu utilization on SUP720-3B/PFC3/MSFC3.
Best regards,
Shinichi
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