04-26-2010 01:03 AM - edited 03-06-2019 10:47 AM
Hi,
QoS classify BGP traffic on Catalist3750 not work.
mls qos
!
interface FastEthernet1/0/24 <- Output Interface
switchport mode access
srr-queue bandwidth share 10 60 40 5
mls qos trust dscp
!
interface Vlan1
ip address 192.168.1.1 255.255.255.0
Other QoS setting is default, and Catalist3750 run BGP.
Switch#sh mls qos int fa 1/0/24 stat
(snip)
output queues enqueued:
queue: threshold1 threshold2 threshold3
-----------------------------------------
queue 0: 2 0 0
queue 1: 1140 2421 777
queue 2: 0 0 0
queue 3: 0 0 0
BGP Traffic through Catalist3750 enqueued queue3, but BGP Traffic from Catalist3750 itself
enqueued queue1 (default queue).
Am I missing something?
Thanks.
04-26-2010 07:38 AM
Routing Protocols and Layer2 features such as Spanning-Tree are placed on a special queue when they are generated by the router.
This information can't be seen with the regular show mls qos commands.
In order to see the packet has the correct marking, inspect the header information while it is being received at the remote end.
I did a quick test to verify if the BGP packets were coming as dscp 0 or dscp cs6.
Rack1SW1#sh run | i access-list 101
access-list 101 permit tcp any any eq bgp dscp default
access-list 101 permit tcp any any eq bgp dscp cs6
access-list 101 permit tcp any eq bgp any dscp cs6
access-list 101 permit tcp any eq bgp any dscp default
Rack1SW1#debug ip packet 101 det
Rack1SW1#sh ip access-lists 101
Extended IP access list 101
10 permit tcp any any eq bgp dscp default
20 permit tcp any any eq bgp dscp cs6
30 permit tcp any eq bgp any dscp cs6
40 permit tcp any eq bgp any dscp default
Few seconds later
Rack1SW1#sh ip access-lists 101
Extended IP access list 101
10 permit tcp any any eq bgp dscp default
20 permit tcp any any eq bgp dscp cs6 (2 matches)
30 permit tcp any eq bgp any dscp cs6 (20 matches)
40 permit tcp any eq bgp any dscp default
Regards
Edison
05-09-2010 07:16 PM
Hi,
thanks for your reply.
I captured packets from Catalyst3750, and those packets had correct marking, dscp cs6.
I did a test to check if BGP packet priority over other packet, I used Smartbit to inject a flow into link, marked with dscp cs0.
The WAN link congested, but BGP neighbor , between Catalyst3750 and remote end router, never down.
Thanks.
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