DNS Proxy Problems: ID Mismatch -> fixed in svn

[jjnoakes]

Host: Windows XP Guest: Ubuntu 10.04 LTS VirtualBox: 3.2.0

I have one NAT network and one host-only network.

I set up DNS Proxy:

$ VBoxManage modifyvm "MyVM" --natdnsproxy1 on

and then I booted up.

In the Ubuntu guest, I can't resolve domain names.

$ cat /etc/resolv.conf nameserver 10.0.2.3 domain search

$ nslookup

server

Default server: 10.0.2.3 Address: 10.0.2.3#53

google.com

;; Warning: ID mismatch: expected ID 9436, got 5376

If I change the nameserver to my ISP's, or anything else (like OpenDNS), things are fine.

My suspicion is that the DNS Proxy is taking in the DNS request from the guest (with ID 9436 in this case), making a request to the Windows resolver (which uses a different ID), getting a response (with that different ID) and forwarding that response directly back to the guest (with the wrong ID). The guest resolver won't accept it.

Or is something else going on?

Either way, this looks to be a bug in the DNS Proxy.

[vasily Levchenko]

Thanks for report. Could you please add the log?

[malattia]

Having the same problem, here is some data:

[mattia@localhost ~]$ cat /etc/resolv.conf
; generated by /sbin/dhclient-script
search <dnssuffix>
nameserver 10.0.2.3

Mismatch:

[mattia@localhost ~]$ dig google.com
;; Warning: ID mismatch: expected ID 1382, got 55557
;; Warning: ID mismatch: expected ID 1382, got 55557
;; Warning: ID mismatch: expected ID 1382, got 55557
;; Warning: ID mismatch: expected ID 1382, got 55813

; <<>> DiG 9.3.6-P1-RedHat-9.3.6-4.P1.el5_4.2 <<>> google.com
;; global options:  printcmd
;; connection timed out; no servers could be reached

on the real DNS:

[mattia@localhost ~]$ dig @<myrealdns> google.com

; <<>> DiG 9.3.6-P1-RedHat-9.3.6-4.P1.el5_4.2 <<>> @<myrealdns> google.com
; (1 server found)
;; global options:  printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 1963
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 0

;; QUESTION SECTION:
;google.com.                    IN      A

;; AUTHORITY SECTION:
com.                    3540    IN      SOA     <...>. 2010053001 28800 7200 604800 3600

;; Query time: 7 msec
;; SERVER: <myrealdns>#53(<myrealdns>)
;; WHEN: Tue Jun  1 15:08:30 2010
;; MSG SIZE  rcvd: 83

In addition, on the host machine (XP) I can see the DNS queries returning a valid reply to the host's DNS proxy when I get the ID mismatch warnings. Unsurprisingly the transaction IDs on the host match those that dig is complaining about in the guest (0xd905 and 0xda05).

[vasily Levchenko]

thanks for reporting. I've been able reproduce the issue. anyway I'd like to get log file, to provide right bits for verification.

[malattia]

Virtual Box logfile

[vasily Levchenko]

Could you please verify the build ​http://www.virtualbox.org/download/testcase/VirtualBox-2010-06-02-07-03-23-win-rel-3.2.1-r62255-MultiArch.exe ?

[malattia]

works fine now, thanks!

[Frank Mehnert]

Thanks for the feedback!