Re: arp cache incomplete entries

[staticsafe <me@staticsafe.ca>]

On 11/10/2012 4:24 PM, Panayiotis Karabassis wrote:
> Hi,
>
> I've noticed that, often, after establishing a connection to the local
> network, important entries in the ARP cache, such as that of my
> nameserver, appear as 'incomplete' and have not an associated hardware
> address. Connection to these hosts often fails.
>
> What are the possible reasons why this could happen? And is there any
> way to repopulate the ARP cache without reconnecting? How is the ARP
> cache populated in the first place?
>
> Unfortunately, I often have to reset my router, and hence LAN
> connections, because of problems with my ISP, so this problem appears
> frequently.
>
> Thanks,
> Panayiotis

Your router usually is the one doing ARP requests (correct me please if 
I'm wrong) in the format:

"Who has x.x.x.x? Tell x.x.x.x"
with a response of
"x.x.x.x is $macaddress"

You can check this behaviour with a tool like Wireshark or tcpdump.

Perhaps this issue is caused by your frequent router resets?

--
staticsafe
http://staticsafe.ca