Rate-limitimg on a BT Megastream Ethernet Aggregation

peter.scott · ‎04-10-2006

Hi,

I'm using a 3750 and have one of the switchports configured as a trunk, but I need to rate-limit the various vlans that are being trunk across it.

At the moment i've configured the following on the vlan interfaces (rate-limit output 50000000 25000 25000 conform-action transmit exceed-action drop), but i'm not sure if this is the best way to configure the switch to control the amount of traffic on the individual vlans.

Here is an example of the configuration:-

Interface Vlan401

Description CustomerA

rate-limit output 50000000 25000 25000 conform-action transmit exceed-action drop

ip address 10.10.10.1 255.255.255.252

!

Interface Vlan402

Description CustomerB

rate-limit output 50000000 25000 25000 conform-action transmit exceed-action drop

ip address 10.10.11.1 255.255.255.252

!

Interface Vlan403

Description CustomerC

rate-limit output 50000000 25000 25000 conform-action transmit exceed-action drop

ip address 10.10.12.1 255.255.255.252

!

Interface GigabitEthernet1/0/25

Description Trunk

switchport

switchport trunk encapsulation dot1q

switchport trunk allowed vlan 1,2,3,4

switchport mode trunk

!

Has anybody tried configuring rate-limiting on vlans on a 3750, and what were you're results?

p.krane · ‎04-12-2006

I think the rate-linit command mentioned in your configuration are not supported on 3750. With that said, we use different QoS implementation to achieve the same result. On cat3750 (and many other catalyst switches), you can configure policer to do input rate-limiting.

http://www.cisco.com/univercd/cc/td/doc/product/lan/cat3750/12220se/3750scg/swqos.htm#wp024977

For output rate-limiting, you can limit the egress port bandwidth with the "srr-queue bandwidth limit" command.

http://www.cisco.com/univercd/cc/td/doc/product/lan/cat3750/12220se/3750scg/swqos.htm#wp1253412

peter.scott · ‎04-13-2006

Thanks for the response.

I did know about the bandwidth command, but i need to rate limit each vlan that is being trunk out of interface GigabitEthernet 1/0/25, which is a new service being offered by BT (Megastream Ethernet Aggregation).