Re: Problem with zone transfers from UltraDNS

[Brian W. <bwe...@xb...>]

On Jan 4, 2012, at 8:41 AM, Deven Phillips wrote:

> Hello,
> 
>      I am attempting to use dnsjava to perform a zone transfer from 
> UltraDNS. I have verified that the zone transfers are allowed and 
> working from Ultra by using:
> 
> dig @<Ultra IP> mydomain.com. AXFR
> 
> I get good results from the dig command, but when I try to use the 
> dnsjava library, I get the following:
> 
> java.io.EOFException
>         at org.xbill.DNS.TCPClient._recv(Unknown Source)
>         at org.xbill.DNS.TCPClient.recv(Unknown Source)
>         at org.xbill.DNS.ZoneTransferIn.doxfr(Unknown Source)
>         at org.xbill.DNS.ZoneTransferIn.doxfr(Unknown Source)
>         at org.xbill.DNS.ZoneTransferIn.run(Unknown Source)
>         at com.zanclus.dns.InboundWorker.run(InboundWorker.java:432)
>         at 
> java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
>         at 
> java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
>         at java.lang.Thread.run(Thread.java:636)
> 
> As best I can tell, the zone transfer connection is getting closed from 
> Ultra's side before the byte count has been fulfilled. The data is 
> complete, but I cannot access it because the Exception does not allow it 
> to be stored and returned in the ZoneTransferIn object. Any suggestions 
> on how to work around Ultra's broken protocol?

If the problem was that not all the bytes were delivered, then the dig command would also fail, since dig also attempts to read full DNS messages before parsing them.  So would any other authoritative server attempting to act as a secondary, so I'm dubious that that's the problem you're seeing.

You could try using the callback-based interface to AXFR in dnsjava 2.1.3 and see if you receive the entire contents before an Exception is raised; if that still doesn't work, I'm not sure what to tell you.  If UltraDNS's servers aren't obeying the protocol, I don't see how any AXFR client would work, as dnsjava isn't doing anything all that different.

Brian