Odd Firewall Problem

[Steven L. Brendtro]

Actually, the gateway of the subnet I am using (192.168.1.1) IS the DHCP
server, so there should be no problem, since it allows all local traffic,
both incoming and outgoing on the internal interface.  The external
interface is the one that has the hardened rules on it.  All the boxes are
getting the DHCP fine, but most of them all of a sudden didn't accept the
DNS and gateway definitions the DHCP server gave the clients.  They get
their IP's and netmask just fine.  That is the odd problem...

Steve.

-----Original Message-----
From: Monty Harder [mailto:kclug at ware.cx]
Sent: Monday, May 14, 2001 8:37 AM
To: Steven L. Brendtro;
Subject: RE: Odd Firewall Problem

5/14/01 12:42:02 AM, "Steven L. Brendtro" <sbrendtro at home.com> wrote:

>Thanks everyone for the pointers... I finally tracked the problem down to
>the Windows clients.  For some reason everything but the DHCP DNS options
>are getting passed from the  network's DHCP server.  My quick fix was to go
>specify the DNS servers on each individual client (ACK).  I am going to
>check Microsoft Technet for notes regarding this issue.  Once again, it
>looks like Microsoft is to blame...  suprise, suprise :)

  Actually, this is =not= Microsoft's problem at all.  DHCP requests are
broadcast, so the default
configuration of a router is to NOT propagate them to the next subnet.  This
is why there's supposed to be
either a DHCP server or relay agent on each subnet.  It is possible to
configure a Linux router to =be= the
relay agent, of course.