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