Maintained by: NLnet Labs

Unbound does not response a forwarded query

Adrian Zhang
Tue Feb 28 06:16:02 CET 2017


When I check Unbound cache, it shows 


unbound-control dump_cache|grep mine.intra
file.mine.intra.	86387	IN	A	10.3.3.50
msg file.mine.intra. IN A 33152 1 47 1 1 0 0
file.mine.intra. IN A 0



3 records about file.mine.intra are generated by one client query.


Adrian


------------------ Original ------------------
From:  "Adrian Zhang via Unbound-users"<unbound-users at unbound.net>;
Date:  Tue, Feb 28, 2017 10:59 AM
To:  "unbound-users"<unbound-users at unbound.net>; 

Subject:  Unbound does not response a forwarded query

 
Hi there,


I am using unbound to forward mine.intra which is a private domain of Microsoft Windows Active Directory due to DNS server on Windows server has the record.


first of all, there is a record file.mine.intra created on DNS server on Windows, and works for clients via running "dig file.mine.intra @IP-OF-WINDOWS".
Second, create forward configuration in unbound.conf and restart Unbound, details are listed below. But Unbound is not able to response to client which run "dig file.mine.intra at IP-OF-UNBOUND"
forward-zone:
        name: "mine.intra."
        forward-addr: 10.3.3.21
        forward-addr: 10.3.3.22
        forward-first: no

(10.3.3.21 is dc1 of mine.intra, 10.3.3.22 is dc2 of mine.intra.)
Finally, I use tcpdump -w to catch packages and save to a file to see that happens. Then using Wireshark to open capture file I get below result.
Time          source.            Dest.               Protocol.            Length.        Info. 
7.841795   client_ip.          Unbound_ip.     DNS                  76               Standard query 0xb80a A file.mine.intra
7.842781   Unbound_ip      Windows_ip.     DNS                  87               Standard query 0xdece A file.mine.intra OPT
7.843769.  ReltekU_e9:..   Broadcast         ARP                   60              Who has IP_OF_Unbound? Tell IP_OF_Windows
7.843788.  ReltekU_64..    ReltekU_e9:..    ARP                   42              IP_OF_Unbound is at 52:54:00:64:37:c7
7.844291.  Windows_ip.     Unbound_ip.     DNS                  103            Standard query response 0xdece A file.mine.intra  A  10.3.3.50 OPT
7.844761.  Unbound_ip.     192.8.128.30.   DNS                  70             Standard query 0x8762 NS <ROOT> OPT


Clearly Windows response the query but Unbound do not receive it and forward response to client, however it continually query ROOT DNS. BTW, these is also standard private domain forwarding settings (same format like above) in the same unbound.conf and works well, such as my-private-domain.com forwarded to a BIND server.


Why this happens and how to make Unbound response client if query a host in xxx.intra?


Thanks in advance.


Adrian
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://unbound.nlnetlabs.nl/pipermail/unbound-users/attachments/20170228/b1a1d7ba/attachment.html>