[nsd-users] nsd4b5: reply from unexpected source

[Andreas Schulze]

Hi,

I normally run nsd with fixed ip-addresses in nsd.conf.

Today I tried to remove all these addresses and nsd listen on INADDR_ANY.
but then I get errors while using secondary addresses:

# ip -4 addr show dev lo
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN
       inet 127.0.0.1/8 brd 127.255.255.255 scope host lo
       inet 127.0.0.53/8 brd 127.255.255.255 scope host secondary lo:53

# netstat -lnp | grep nsd
tcp        0      0 0.0.0.0:53              0.0.0.0:*                
LISTEN      18170/nsd
tcp        0      0 :::53                   :::*                     
LISTEN      18170/nsd
udp        0      0 0.0.0.0:53              0.0.0.0:*                   
          18170/nsd
udp        0      0 :::53                   :::*                        
          18170/nsd

# dig @127.0.0.1 hostname.bind -c CH -t txt +short
"example"

BUT:
# dig @127.0.0.53 hostname.bind -c CH -t txt +short
;; reply from unexpected source: 127.0.0.1#53, expected 127.0.0.53#53

I think, there was a similar discussion on nsd-users or unbound-users  
but found nothing here...

Reason behind this question is a redundancy problem. I have 2 server  
providing name-service.
The service-address is maintained by a keepalived. So sometimes when  
nsd try to start, the service-address
is located on the other host. listen to a specific address fail, nsd  
don't start :-(

For that reason I also tried the "ip-transparent" option.
But I get still: error: can't bind udp socket: Cannot assign requested address

Any hints?

Andreas