Does anyone have any tricks for rate-limiting a pair of customer facing L3 interfaces w/ HSRP across 2 chassis? I'm working on a co-lo setup and I was thinking about how I'm going to rate-limit the customer and still implement HSRP for access layer redundancy. Another engineer's question got me wondering.
I was planning on applying the same rate-limits to the customer's L3 HSRP interfaces on both routers. However the customer could easily point half their servers at the interface IP on the standby L3 interface and it will gladly accept and route their traffic. Of course all return traffic would come through the active HSRP interface but since most co-lo traffic is upstream that rate-limit wouldn't prevent the simultaneous use of both HSRP routers. Is there a HSRP option to tell the standby router to only route traffic when it's active? VRRP and GLBP would have the same problem I imagine. Or is the solution to not pull the interface IPs out of the same block as the floating standby IP, ie address the interfaces with RFC1918 addresses? This way the interface IPs wouldn't be routable from the customer's server unless the customer bound the appropriate private subnet to one of their interfaces and at that point their traffic wouldn't be routable across the 'Net. I know this has been discussed here dozens of times but I can't remember what the consensus was. My other rate-limit question was about calculating the figures for CAR. I once found a nice page that gave suggestions for what formula to use in certain circumstances to calculate burst sizes. I can't find that bookmark now and my Google-fu isn't turning up anything helpful. Does anyone know the page or a similar one? Or does anyone have a suggestion for burst size calculations? Thanks Justin _______________________________________________ cisco-nsp mailing list cisco-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/