unknown UDP caused by dhclient

[Kimmo Paasiala]

On Thu, Jun 4, 2015 at 10:31 AM, Matthias Apitz <guru at unixarea.de> wrote:
>
> Hello,
>
> I'm seeing in my firewall log unknow UDP traffic which is caused by the
> running dhclient:
>
> Jun  3 21:57:02 c720-r276659 dhclient[2601]: send_packet: Network is unreachable
> Jun  3 21:57:02 c720-r276659 ipmon[2368]: 21:57:02.751350 ue0 @0:82 b 10.42.0.83,68 -> 10.42.0.1,67 PR udp len 20 328 OUT
> Jun  3 21:58:38 c720-r276659 dhclient[2601]: send_packet: Network is unreachable
> Jun  3 21:58:38 c720-r276659 ipmon[2368]: 21:58:38.753118 ue0 @0:82 b 10.42.0.83,68 -> 10.42.0.1,67 PR udp len 20 328 OUT
>
> What is my dhclient asking from the router 10.42.0.1? Should I open the
> ipfilter for this?
>
> The system is r276659.
>
> Thanks
>
>         matthias
> --
> Matthias Apitz, guru at unixarea.de, http://www.unixarea.de/ +49-170-4527211    +49-176-38902045
> "Wenn der Mensch von den Umständen gebildet wird, so muß man die Umstände menschlich bilden."
> "Si el hombre es formado por las circunstancias entonces es necesario formar humanamente
> las circunstancias", Karl Marx in Die heilige Familie / La sagrada familia (MEW 2, 138)


That is how a DHCP client ask for lease renewal from the DHCP server,
you should allow the traffic if the interface in question is
configured to use DHCP.

-Kimmo