Bug 652

Summary: NSD replies from unexpected source
Product: NSD Reporter: jybisiaux <jyb>
Component: NSD CodeAssignee: NSD team <nsd-team>
Status: ASSIGNED ---    
Severity: normal CC: wouter
Priority: P5    
Version: 3.2.x   
Hardware: x86_64   
OS: FreeBSD   

Description jybisiaux 2015-03-17 11:10:45 CET
Hello When no ip-address is configured in the nsd conf file, NSD replies on unexpected IP address source - the server is multi-homed or have multiple interfaces.

Workaround: define IP address interfaces.
Comment 1 Wouter Wijngaards 2015-03-17 11:53:56 CET
Hi jybisiaux,

Yes this  is caused by the OS not routing the packets properly in the 'multihomed' interface setup.

The option ip-transparent: yes in nsd.conf can be used to bind to non-local addresses, so you can give the ip addresses you want in nsd.conf and start nsd even before you bring up the interface.  (for those load-balancer type situations).

Configure the ip-addresses is not a workaround, but the resolution of the problem.

Best regards,
   Wouter
Comment 2 jybisiaux 2015-03-17 12:35:47 CET
Hello Wouter,

Thank you for your prompt answer.

I think you should store the target IP address of the query in order to send the answer  from the same interface it came. 

PS: BIND do it. ;-)