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Web Hosting and Cloud Computing Control Panels
Howdy,
Yeah, that connection timed out error is a bit unusual... do you receive that for any other lookups as well? Or just the one you showed there?
When that occurs, are you seeing any errors in any of your logs?
-Eric
Hi Eric,
Yeah it occurs on a few domains, code.jquery.com, and cdn.sublimevideo.net to name another one. i just cant see why my local dns lookup would be blocked on certain domains.
Paul
I'd start out by checking the exact delegation path of the problematic domain, using
dig domainthatdoesntwork.com +trace. You might want to post the result here for further inspection. :)Does the problem occur with all third-level domains?
Ok, a bit more digging and i've come up with this. These cant be resolved:
code.jquery.com (jquery.com is resolved) - edgecast cdn.sublimevideo.net (sublimevideo.net resolved) - edgecast
However I can access:
code.google.com en.wikipedia.org help.yahoo.com
However, I cant access http://www.edgecast.com/ which is the cdn for sublime and jquery. So it is sounding highly likely (as said in discussions from serverfault) that my ip address is being blocked by edgecast when doing dns lookups?
Can you please, as I requested, post the result of a "dig +trace" for a domain that doesn't work?
sure:
dig edgecastcdn.net +trace
; <<>> DiG 9.8.2rc1-RedHat-9.8.2-0.10.rc1.el6_3.5 <<>> edgecastcdn.net +trace
;; global options: +cmd
. 336970 IN NS c.root-servers.net.
. 336970 IN NS j.root-servers.net.
. 336970 IN NS m.root-servers.net.
. 336970 IN NS l.root-servers.net.
. 336970 IN NS i.root-servers.net.
. 336970 IN NS d.root-servers.net.
. 336970 IN NS b.root-servers.net.
. 336970 IN NS k.root-servers.net.
. 336970 IN NS f.root-servers.net.
. 336970 IN NS e.root-servers.net.
. 336970 IN NS h.root-servers.net.
. 336970 IN NS a.root-servers.net.
. 336970 IN NS g.root-servers.net.
;; Received 508 bytes from 127.0.0.1#53(127.0.0.1) in 4 ms
net. 172800 IN NS a.gtld-servers.net.
net. 172800 IN NS b.gtld-servers.net.
net. 172800 IN NS c.gtld-servers.net.
net. 172800 IN NS d.gtld-servers.net.
net. 172800 IN NS e.gtld-servers.net.
net. 172800 IN NS f.gtld-servers.net.
net. 172800 IN NS g.gtld-servers.net.
net. 172800 IN NS h.gtld-servers.net.
net. 172800 IN NS i.gtld-servers.net.
net. 172800 IN NS j.gtld-servers.net.
net. 172800 IN NS k.gtld-servers.net.
net. 172800 IN NS l.gtld-servers.net.
net. 172800 IN NS m.gtld-servers.net.
;; Received 490 bytes from 193.0.14.129#53(193.0.14.129) in 923 ms
edgecastcdn.net. 172800 IN NS ns1.edgecastcdn.net.
edgecastcdn.net. 172800 IN NS ns2.edgecastcdn.net.
;; Received 101 bytes from 192.43.172.30#53(192.43.172.30) in 11066 ms
;; connection timed out; no servers could be reached
Okay, it indeed seems that for some reason DNS requests from your test system to "ns*.edgecastcdn.net" are blocked.
The IPs are as follows:
You might want to try "mtr" to trace the route to those nameservers and see where it fails. It should look like this if it works okay:
Host Loss% Snt Last Avg Best Wrst StDev 1. rigel.tianet.de 0.0% 23 0.2 0.2 0.2 0.3 0.0 2. static.1.106.9.176.clients.your-server.de 0.0% 23 2.3 1.9 0.8 4.4 1.3 3. hos-tr1-juniper1.rz15.hetzner.de 0.0% 23 0.4 0.5 0.4 1.8 0.3 4. hos-bb1.juniper1.ffm.hetzner.de 0.0% 23 5.0 5.1 5.0 5.7 0.1 5. r1fra1.core.init7.net 0.0% 23 14.5 8.2 5.1 15.2 4.0 6. xe-0.de-cix.frnkge03.de.bb.gin.ntt.net 0.0% 23 7.1 14.0 6.6 104.8 22.3 7. ae-1.r02.frnkge03.de.bb.gin.ntt.net 13.6% 22 6.4 9.0 6.2 23.7 4.5 po-1.r01.frnkge03.de.bb.gin.ntt.net 8. edgecast-0.r01.frnkge03.de.bb.gin.ntt.net 0.0% 22 6.0 6.3 5.8 6.9 0.3 edgecast-0.r02.frnkge03.de.bb.gin.ntt.net 9. ns1.edgecastcdn.net 0.0% 22 6.0 6.1 5.8 7.3 0.4