Interesting DNS Error

[kipcrist]

We use openDNS as our DNS server for FirstSpot as configured on the Visitor NIC. The primary/secondary servers in the DHCP tab are left as 0.0.0.0.


I've had a number of customers complain they cannot connect to the facebook app frontierville. After a cold reboot, I was able to connect to the application but after 24 hours, I could not any longer (probably because another customer had tried to connect or something). I found this surprising so I began some packet level inspecting. I noticed that there were DNS errors occurring on the lookup for "fb-0.frontier.zynga.com" I performed the lookup from the FirstSpot server and it successfully obtained DNS results. I performed it from a computer using the FirstSpot DNS information and it provided the following error:
C:\>nslookup fb-0.frontier.zynga.com
Server: belmontwifi.com
Address: 10.20.7.1

*** belmontwifi.com can't find fb-0.frontier.zynga.com: Unspecified error

After changing the DNS settings in the client computer to the openDNS servers directly, it successfully obtained the information and the application loaded.

This definitely sounds like an issue with how FirstSpot is obtaining and handling DNS lookups...especially since the FirstSpot server successfully obtains the information, it just doesn't hand it out correctly.

[kipcrist]

Any followup on this?

[alan]

Can issue the below commands in the client PC:

nslookup
set d2
fb-0.frontier.zynga.com

and post the output here?
_________________
~ Patronsoft Limited ~

[kipcrist]

Microsoft Windows XP [Version 5.1.2600]
(C) Copyright 1985-2001 Microsoft Corp.

C:\Documents and Settings\Administrator>ipconfig /all

Windows IP Configuration

Host Name . . . . . . . . . . . . : TestService
Primary Dns Suffix . . . . . . . :
Node Type . . . . . . . . . . . . : Unknown
IP Routing Enabled. . . . . . . . : Yes
WINS Proxy Enabled. . . . . . . . : Yes

Ethernet adapter Local Area Connection:

Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Intel(R) PRO/100 VM Network Connecti
on
Physical Address. . . . . . . . . : 00-08-02-3B-08-29
Dhcp Enabled. . . . . . . . . . . : No
IP Address. . . . . . . . . . . . : 10.20.7.14
Subnet Mask . . . . . . . . . . . : 255.255.240.0
Default Gateway . . . . . . . . . : 10.20.7.1
DNS Servers . . . . . . . . . . . : 10.20.7.1
NetBIOS over Tcpip. . . . . . . . : Disabled

C:\Documents and Settings\Administrator>nslookup
Default Server: belmontwifi.com
Address: 10.20.7.1

> set d2
> fb-0.frontier.zynga.com
Server: belmontwifi.com
Address: 10.20.7.1

------------
SendRequest(), len 41
HEADER:
opcode = QUERY, id = 2, rcode = NOERROR
header flags: query, want recursion
questions = 1, answers = 0, authority records = 0, additional = 0

QUESTIONS:
fb-0.frontier.zynga.com, type = A, class = IN

------------
truncated answer
connect failed: No error
SendRequest failed
------------
SendRequest(), len 41
HEADER:
opcode = QUERY, id = 3, rcode = NOERROR
header flags: query, want recursion
questions = 1, answers = 0, authority records = 0, additional = 0

QUESTIONS:
fb-0.frontier.zynga.com, type = A, class = IN

------------
truncated answer
connect failed: No error
SendRequest failed
*** belmontwifi.com can't find fb-0.frontier.zynga.com: Unspecified error
>

[kipcrist]

Does this give you any clues?