[c-nsp] asr9k dhcp relay + ipv4 verify unicast

[Saku Ytti]

On 23 May 2016 at 17:56, Phil Mayers <p.mayers at imperial.ac.uk> wrote:
> I know nothing about -XR but surely if uRPF was eating packets with source
> of 0.0.0.0, the DISCOVER wouldn't make it to the server?

You're right, I most confess I didn't read email fully before
responding, apologies to OP for it.

> Seeing a DISCOVER at the server but no request sounds like the OFFER getting
> dropped, which can happen if the route back to the giaddr from the server
> hits an RPF failure (beyond tedious in ECMP-enabled HSRP setups as we
> recently discovered...)

Right, so speculation is, we offered something else than 10.4.5/24

Anyhow if it's low volume box, we can capture the NPU counter which
does uRPF drop, to see the exact packet being dropped.

Small script to find NPU captures in a session log and turn them into
PCAP - https://gist.github.com/ytti/436fe3b602a963acf21e

-- 
  ++ytti