CSS multihome routing question

[admin_2]

Hello.

I don't have a lot of experience with CSS, so, let me know, if my question is dumb. :)

Is it possible to configure CSS to send packets back to clients throuh the same interface that client's request came from? I.e. If client establishes connection to ip1 (see diagram below), all replies need to be sent through provider1. Same with ip2 and provider2. Any sample configs on this?

Thank you.

The diagram (sorry if reformated):

provider1------[ip1-CSS-ip2] ----provider2

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[web server farm]

[Gilles Dufour]

this is the default behavior of the CSS.

This is called 'ECMP' routing.

Again, this is the default behavior.

You can change it with the command 'ip ecmp no-prefer-ingress'

Gilles.

[#3]

Just to confirm...

If there are two default routes with the same metric, CSS will select one depending on where the request came from, regardless of the order how that routes appear in CSS configuration, right?

Thanks,

Max.

[Gilles Dufour]

correct.

However, it was brought to my attention that if you have a lot of clients that come from both ISP (so the CSS needs to update the ingress side info all the time) you could create some high cpu issues.

Gilles.