I have four Linux servers at different sites, all connected to different uk ISPs via (until recently) different routers. Each server is using SpamAssassin, and searching for updates to the SpamAssassin rules requires doing a DNS lookup for TXT records. All has been working fine, until I replaced the routers at two sites with one Vigor 2830 and one Vigor 2830n. Now, on those servers with the Vigor routers, I can't get my TXT lookups to work. From the two non-vigor servers, I can run dig @8.8.8.8 -t A 2.3.3.updates.spamassassin.org to get the A record for 2.3.3.updates.spamassassin.org from google's DNS server, or dig @8.8.8.8 -t TXT 2.3.3.updates.spamassassin.org to get the TXT record, and it all works fine. From either of the two sites that use the Vigor routers, the same command for the A record works as expected, but the command for the TXT record just times out. Where I should get this:
; <<>> DiG 9.9.2-P1 <<>> @8.8.8.8 -t TXT 2.3.3.updates.spamassassin.org
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 13966
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 512
;; QUESTION SECTION:
;2.3.3.updates.spamassassin.org. IN TXT
;; ANSWER SECTION:
2.3.3.updates.spamassassin.org. 2479 IN TXT "1528373"
;; Query time: 40 msec
;; SERVER: 8.8.8.8#53(8.8.8.8)
;; WHEN: Thu Oct 3 10:19:57 2013
;; MSG SIZE rcvd: 79
instead I just get this:
; <<>> DiG 9.9.2-P1 <<>> @8.8.8.8 -t TXT 2.3.3.updates.spamassassin.org
; (1 server found)
;; global options: +cmd
;; connection timed out; no servers could be reached
Since things were working at both sites before I changed the routers I'm suspicious that the Vigors are doing something unexpected (although I haven't yet been able to switch back to confirm this). On both routers the call filter and data filters are disabled. An IPSec VPN has been set up between the two Vigor routers, but the behaviour is the same if I deactivate the VPN.
Can anyone suggest how I might investigate this further?
