Hey, > So I'm looking at the policies, recommended configurations, etc. of other > IXes. We try to model a lot of ourselves on what the Europeans do (even if we > come up short in some areas). I was reading through the AMS-IX guide. > > https://ams-ix.net/technical/specifications-descriptions/config-guide#3.1 > > They recommend a four hour ARP timeout. Thoughts? Seems a bit excessive, but > I don't have over 700 networks on my IX. That said, I don't have over 700 > members on my IX generating a ton of ARP traffic, so I'm probably fine > recommending a smaller value. > > I understand it's a balance between stale records and ARP volume. Just trying > to gauge what the community thinks.
I don't think it matters much and at any rate you can't enforce it. Someone more relevant is that MAC timeout is greater than ARP timeout. And on IXP even this is not very important, provided no one is static routing. On environments I do control, I tend to configure ARP timeout under 300s, as usually MAC timeouts are 300s. By default Cisco is 4h, JunOS is 20min, Linux is 60s. -- ++ytti
