IX ARP Timeout

Thu Jan 28 07:06:12 UTC 2016

> 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. 

As far as I know 4 hours has been the Cisco IOS default for many years.
So you'll find millions of routers around the world with that value. I
agree that it may be excessive in some situations.

Steinar Haug, Nethelp consulting, sthaug at nethelp.no