"(or we can use proxy ARP on the router if it becomes a problem)." You're a braver man than I. Personally, the prospect of troubleshooting proxy-arp at 3 am doesn't sound like much fun. -James -----Original Message----- From: ripe-atlas-bounces@ripe.net [mailto:ripe-atlas-bounces@ripe.net] On Behalf Of Baptiste Jonglez Sent: Friday, August 15, 2014 12:07 AM To: ripe-atlas@ripe.net Subject: Re: [atlas] Probe on a /31 or /32 IPv4 network On Fri, Aug 15, 2014 at 06:23:09AM +0200, Mikael Abrahamsson wrote:
On Thu, 14 Aug 2014, Baptiste Jonglez wrote:
Using a gateway that is not on the same subnet doesn't sound very nice, but again, the goal is to avoid wasting precious IPv4 space.
What router platform are you using upstream from the probe? Doing a /32 per vlan(ie sharing a larger subnet between different vlans) is perfectly possible on several routing platforms.
We're using Linux. Actually, we are already routing a /32 per VLAN on the router, but up to now, we were also setting up /32 "subnets" on the downstream routers or hosts.
Interesting read. It basically amounts to use /32 routes on the router, and a larger subnet (e.g. /24) on hosts, as Philip suggests. This is a bit of a hack when hosts want to talk to each other, but this is mostly ok for the probe (or we can use proxy ARP on the router if it becomes a problem). Thanks for the help, Baptiste