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ifconfig and alias problems?



I've been having a heck of a time trying to troubleshoot this if
anyone has any ideas I'd greatly appreciate it.

Situation:
I have a server running OpenBSD 2.8 on a DMZ segment (10.2.x.x/16)
that's hosting DNS via djbdns. TinyDNS is bound to the primary IP,
10.2.4.1/16 and DNSCache is aliased to 10.2.4.2/16. All computer on
the internal segment can access DNS with no problems. All computers on
the same subnet can not. Computers on the DMZ segment can use all
services as long as it's by IP rather than name which make me believe
it's not a cable or switch issue. Computers on the DMZ segment are a
mixed bunch of NT and OpenBSD machines.

If I run tcpdump udp on the DNS server I can see the DNS request
coming in but I never see the response. Logfiles for DNScache show the
lookup but I never see the response. Doing an arp -a shows the arp
entries for the computers I'm testing DNS from. One thing I noticed is
when I reboot it sets the aliased IP address's gateway to 127.0.0.1,
is this normal?

Relevant info is included below. If I left out anything that will help
troubleshoot this, please let me know and I'll post it.

Thanks,
Jason Stout

komodo# ifconfig -A
lo0: flags=8009<UP,LOOPBACK,MULTICAST> mtu 32972
inet 127.0.0.1 netmask 0xff000000
lo1: flags=8008<LOOPBACK,MULTICAST> mtu 32972
xl0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
media: Ethernet autoselect (100baseTX full-duplex)
status: active
inet 10.2.4.1 netmask 0xffff0000 broadcast 10.2.255.255
inet 10.2.4.2 netmask 0xffffffff broadcast 10.2.4.2
tun0: flags=10<POINTOPOINT> mtu 3000
tun1: flags=10<POINTOPOINT> mtu 3000
enc0: flags=0<> mtu 1536
enc1: flags=0<> mtu 1536
enc2: flags=0<> mtu 1536
enc3: flags=0<> mtu 1536

komodo# arp -a
? (10.2.0.254) at 0:c0:95:e4:8e:70 #Gateway for this subnet
? (10.2.1.9) at 0:d0:b7:90:bb:f3 #Machine I was testing DNS from.

komodo# cat /etc/hostname.xl0
inet 10.2.4.1 255.255.0.0 NONE media autoselect
inet alias 10.2.4.2 255.255.255.255 NONE

komodo# tcpdump udp
tcpdump: listening on xl0
<snip>
10:51:06.693000 10.2.1.9.38701 > 10.2.4.2.domain:  64329+ A?
www.OpenBSD.org. (33)
10:51:08.524678 199.107.171.254.2566 > 10.2.4.2.domain:  11775+ PTR?
200.17.240.63.in-addr.arpa. (44)
10:51:08.525261 10.2.4.2.domain > 199.107.171.254.2566:  11775 NXDomain*
0/0/0 (44)
10:51:11.702940 10.2.1.9.3828 > 10.2.4.2.domain:  64329+ A?
www.OpenBSD.org. (33)
10:51:14.008279 199.107.171.254.2567 > 10.2.4.2.domain:  11440+ PTR?
200.17.240.63.in-addr.arpa. (44)
10:51:14.008772 10.2.4.2.domain > 199.107.171.254.2567:  11440 NXDomain*
0/0/0 (44)
<snip>
321 packets received by filter
0 packets dropped by kernel


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