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Old 11-01-2006, 08:53 AM   #1
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Registered: Sep 2002
Location: Lewisville, Texas
Distribution: Debian / [K]Ubuntu
Posts: 13

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UDP Response with a Multihomed NIC

Hello All,
For various reasons, I have a server with one NIC multihomed with 2 IP addresses assigned:
PHP Code:
I am running a DNS server which listens on both IPs. When I run a DNS query on the ip address linked to eth0 I get a correct response:

PHP Code:
Default Server:  []
:  []

-authoritative answer:

When I query the multihomed IP I get an error:

PHP Code:
Default Server:  []
:  []

DNS request timed out
timeout was 2 seconds.
DNS request timed out.
timeout was 2 seconds.
Request to [ 

From what I can tell, the linux server receives the DNS query on eth0:1 ( but replies with the correct answer from eth0 ( My windows machine making the request isn't expecting a response from the *.97 address so it drops it.

Can anyone tell me how I can force the response out through the IP address in which it was received? I believe this is a routing problem but I have not been able to figure it out.

Here is what my routing table looks like:
PHP Code:
root@0[powerdns]# route -n
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    
Use Iface   U     0      0        0 eth0         UG    0      0        0 eth0         UG    0      0        0 eth0 


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