How to Rate-Limit a Layer 2 Switch Port?

Unanswered Question

One of our Telco service providers is asking if we can rate-limit traffic leaving our facility into their network. Their link is used to extend one of our Vlans to a DR site across the state. Our switch port facing their equipment is Gig/E, and they want us to rate-limit it back to 150Mb. Our equipment is a 6513 with Sup720 and WS-X6748-GE-TX Blades.

I have this problem too.
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Joseph W. Doherty Thu, 05/28/2009 - 17:08

Because of the way policers work, if you find you're bumping up against the rate-limits often, you might want to take special note of the information in Jon's reference concerning the Tc and burst parameters.

As an alternative, you might want to pursue a "shaping" solution, but that's not supported, I believe, on your LAN Ethernet card, the 6748. Believe you would need to run Ethernet off either a FlexWAN or SIP-200/400 card. Or, drop another device in-line that offers some kind of shaping and, optionally, multiple queues (e.g., perhaps one of the least expensive would be a 2960G-8TC-L).

The examples provided in your link seem to require a Layer 3 environment. Our situation has the port that faces Telco defined as an access switchport. The link across the Telco network is essentially an extension of the Vlan assigned to that port. The Microflow Policing option looked promising, but apparently doesn't apply to egress traffic.

Can anyone clarify the info from the link, or recommend another approach?


- Jay


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