[Unbound-users] Resolving of some special host very slow

[lst_hoe02 at kwsoft.de]

Hello,

today we discovered a hostname which is very slow to resolv with  
Unbound 1.4.21 as validating resolver. It works fine with all knid of  
other resolvers and oddly enough even with another Unbound instance.
The host in question is esta.cbp.dhs.gov and resolve time after it is  
not in the cache range from around 2 to 5 seconds. I have take a  
tcpdump and can only see that the first answer come much faster but  
Unbound keeps asking for the same A record on different nameservers  
again and again.

Any idea what is going wrong?

Thanks

Andreas