Saturday, August 14, 2010

Deadwood snapshot update: Working around aplus.net’s broken DNS server

Aplus.net’s DNS server is broken.

Let’s contact their DNS server for the A record for bookride.com:

$ dig @64.29.144.70 www.bookride.com

; <<>> DiG 9.3.6-P1-RedHat-9.3.6-4.P1.el5_4.2 <<>> @64.29.144.70 www.bookride.com
; (1 server found)
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 10397
;; flags: qr aa rd; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 0

;; QUESTION SECTION:
;www.bookride.com. IN A

;; ANSWER SECTION:
www.bookride.com. 3600 IN CNAME ghs.google.com.

;; AUTHORITY SECTION:
google.com. 86400 IN SOA ns1.aplus.net. hostmaster.aplus.net. 1007 86403 3600 3600000 86400

;; Query time: 304 msec
;; SERVER: 64.29.144.70#53(64.29.144.70)
;; WHEN: Sat Aug 14 01:18:15 2010
;; MSG SIZE rcvd: 119

This is an invalid packet: It is marked as a NXDOMAIN (complete with a SOA record in the NS/Authority section), but it is actually a CNAME.

I have updated Deadwood to treat these broken packets like ordinary CNAME packets. The snapshot can be downloaded here:

http://maradns.org/deadwood/snap/

I am also in the process of trying to file a bug report with aplus.net.