ARP weirdness.

[Ben Scott]

On Wed, Nov 8, 2017 at 4:49 PM, Ken D'Ambrosio <ken at jots.org> wrote:
> Ubuntu box acting as a router for some subnets.
>
> [192.168.200.12] <-1302 VLAN->[switch]<-1302 VLAN->switch<-1302 VLAN->
> [router @ 192.168.200.1]

So, to clarify, the Ubuntu box is at .1?  What is .12?

Can you give a concise description of what else is on the VLAN?

> The link is getting utterly spammed with ARP requests for
> 192.168.200.12.

How are you determining this?  Packet sniffer?  If so, where?

Are these ARP requests originating from the .1 box?  You have verified
this by MAC address of the sending system?  If you unplug .1 to test,
does the flood stop?

One thought that immediately occurs to me is a broadcast loop.  Any
chance of a physical loop (e.g., cable plugged into two switch ports
on the same VLAN)?  Are you running spanning tree any/everywhere?

What are the switches?  Any particular config applied to the VLANs,
beyond the VLAN itself?  Any weird config applied to the switch in
general?

-- Ben