DHCPd using wrong interface

[glenn.satchell at uniq.com.au]

Hi Dan,

Typically something like this, replace eth0 with the interface you want 
to trace packets on. If you have wireshark you can use that instead. 
There's all sorts of filtering you can apply, but if traffic is light 
this will be sufficient.

tcpdump -i eth0

regards,
Glenn

On 2020-12-23 02:43, Dan Egli wrote:
> On Tue, Dec 22, 2020 at 07:07:49PM +1100, glenn.satchell at uniq.com.au 
> wrote:
>> Hi Dan
>> 
>> Which bind server is it trying to update? Those updates are sent as
>> unicast packets and are subject to normal routing rules. Perhaps it's
>> trying to update the ISP's DNS server?
>> 
>> Can you use tcpdump to see what the destination IP address is?
> 
> That may be workable. I'm actually away from the machines until much
> later tonight. The only question I have is how to use tcpdump as I've
> never used it before. I take it from reading the man page that I just
> run tcpdump while a machine is obtaining a lease on an IP?
> 
> Sorry, I'm still learning a lot.
> 
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