dhcp problems (i think)

[cape canaveral]

On Sat, 6 Nov 2004 11:46:14 -0800, Charlie Root <root at thought.org> wrote:
> On Sat, Nov 06, 2004 at 10:51:50AM -0800, cape canaveral wrote:
> 
> 
> > On Sat, 6 Nov 2004 10:28:36 -0800, Gary Kline <kline at magnesium.net> wrote:
> > > On Sat, Nov 06, 2004 at 12:46:21PM -0500, Lowell Gilbert wrote:
> > >
> > >
> > > > Gary Kline <kline at magnesium.net> writes:
> > > >
> > > > >     I messed up something on myh primary server, where I run
> > > > >     dhcp.  Since I did whatever-it-was, ssh takes at least two
> > > > >     minutes to get from NS1 (aka 'sage'), and anywhere else.
> > > > >
> > > > >     Only on sage can I type 'ping foo.org' and get an immediate
> > > > >     responce.  On any other server, typing 'ping' hangs forever.
> > > > >     There is no "No route to server" error.  Of course nothing
> > > > >     else works across my private network.  Nothing is
> > > > >     resolvable.  This suddenly since around 18:00 local time.
> > > > >
> > > > >     In /var/db, myleases look valid.  (I just installed the newest
> > > > >     dhcp-server.  Zip.  Anbody know where I'm screwing up?
> > > >
> > > > Sounds more like DNS problems...
> > > >
> > >
> > >         I did have one DNS error having to do with an incorrectly
> > >         listed secondary.  Fixed it; made sure.  Still same symptoms.
> > >
> > >         (I *was* mucking around with adding phpbb and other ports
> > >         a few hours before dhcpd went south... Can't imagine how
> > >         this would have affected anything.)
> > >
> > >
> > >
> >
> > Verify you can hit the other machine by IP, which will let you know
> > (hopefully) whether it's DNS or routing.  Verify the contents of
> > /etc/resolv.conf and the output of ifconfig -a maybe they will tell
> > you something.
> >
> > 
>         From here (sage == ns1) I have no network problems;
>         I can ping tao, sartre, zen, and ethic, no prob.
>         Of course, these are in my /etc/hosts file.
> 
>         Here is the output from ifconfig -a.
> 
> root at sage:/etc# ifconfig -a
> dc0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
>         inet6 fe80::220:78ff:fe02:71ba%dc0 prefixlen 64 scopeid 0x1
>         inet 216.231.43.140 netmask 0xffffff00 broadcast 216.231.43.255
>         ether 00:20:78:02:71:ba
>         media: Ethernet autoselect (10baseT/UTP)
>         status: active
> dc1: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
>         inet6 fe80::20c:41ff:fe20:2bb6%dc1 prefixlen 64 scopeid 0x2
>         inet 10.0.0.1 netmask 0xff000000 broadcast 10.255.255.255
>         ether 00:0c:41:20:2b:b6
>         media: Ethernet autoselect (100baseTX <full-duplex>)
>         status: active
> pcn0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
>         inet6 fe80::260:b0ff:fef1:59b9%pcn0 prefixlen 64 scopeid 0x3
>         inet 0.0.0.0 netmask 0xff000000 broadcast 255.255.255.255
>         ether 00:60:b0:f1:59:b9
>         media: Ethernet autoselect (none)
>         status: no carrier
> plip0: flags=8810<POINTOPOINT,SIMPLEX,MULTICAST> mtu 1500
> lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> mtu 16384
>         inet6 ::1 prefixlen 128
>         inet6 fe80::1%lo0 prefixlen 64 scopeid 0x5
>         inet 127.0.0.1 netmask 0xff000000
> root at sage:/etc#
> 
>         dc0 goes to my IDSL router; dc1 goes to the hub/switch.
>         These look okay.  Am I missing something?
> 
>         gary
> 
>         PS: FWIW, I was also messing with things-firewall
>             Thursday evening.  Everything-firewall is now set="NO".
> 
> 
For the machine that can't connect to anything, can it
ping/ssh/whatever to services on your LAN by IP address?  If so, can
it ping/ssh/whatever to services on the Internet?  Need to narrow it
down to either DNS or network config.

The problem still sounds like DNS to me.  Either bad resolver IP(s)
provided by the DHCP server or bad tcp/ip configuraiton preventing the
machine from getting to a working DNS server.  Check /etc/resolv.conf
on the broken machine and verify that it contains working recursive
DNS servers (ie, with dig).

Sorry I cannot offer more specifics, I have never used FreeBSD as a
network gateway, so am not personally familiar with its configuration
in that regard.