DNS Troubleshoot. Campus domain does not resolve when using campus network

dnsopenwrt

I am having a very odd DNS issue. I live on-campus and the university provides Internet access with my rent, but I can not get access to the university websites. I am hoping to get direction on how to diagnosis my specific DNS issue as described below. Thanks a ton!

I have an OpenWRT base router/firewall – 10.3.1-rc4 that works just grand. I have no issues what so ever, except when I use the campus network, I can no resolve the university's domain.

I have verified that OpenWRT is using the campus name servers:

root@tdwrt:~# cat /tmp/resolv.conf.auto 
    nameserver 10.35.60.8
    nameserver 10.25.60.2
    search resnet.uwyo.edu
    root@tdwrt:~# wget http://google.com
    Connecting to google.com (209.85.225.105:80)
    Connecting to www.google.com (209.85.225.147:80)
    index.html           100% |**************************************************************|  8746  --:--:-- ETA
    root@tdwrt:~# wget http://uwyo.edu  
    wget: bad address 'uwyo.edu'
    root@tdwrt:~# ping -c5 uwyo.edu
    ping: bad address 'uwyo.edu'
    root@tdwrt:~#

I signed up for 3rd party ISP for two months and when using the cable co as my ISP, I can resolve the university site just fine. But why pay $40 per mo, when it is suppose to be included in my rent?!

I have also re-flashed the device to get rid of any potential malformed configs.

I run "tcpdump -n -i br-lan | grep .53 | grep domain.com" and then try to access the domain, but I do not get any output. When I run the same (with different interface) on my workstation, it shows the router being queried for address.

05:01:12.516403 IP 192.168.1.5.59064 > 192.168.1.1.53: 64580+ AAAA? uwyo.edu. (26)
05:01:12.521326 IP 192.168.1.5.57653 > 192.168.1.1.53: 31772+ AAAA? uwyo.edu. (26)
05:01:12.528271 IP 192.168.1.5.41321 > 192.168.1.1.53: 17466+ A? uwyo.edu. (26)
05:01:12.537111 IP 192.168.1.5.47016 > 192.168.1.1.53: 50397+ A? uwyo.edu. (26)

I started a trouble ticket back in May 2009 and updated it through out the summer. I can not get the university support to touch it. Its easy to think its a problem with my router, but I say it is not so easy since EVERY other domain is just fine and even uwyo.edu works just fine when using 3rd party ISP. The problem seems to be a combo of how UW does there stuff and OpenWRT..

Best Answer

It seems that the campus has a special configuration for its own domain.
The UDP name resolution queries are probably not handled the same way when coming from the local private network (10...*) or from the public networks (Internet).

Did you try 

  dig uwyo.edu

or 

  host -a uwyo.edu

Anyway, if you use the Google DNS servers, you are likely to get your problem fixed, since the NS is outside the campus on the public side.

Change /tmp/resolv.conf.auto with

nameserver 8.8.8.8
nameserver 8.8.4.4
search resnet.uwyo.edu
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