Re: Are the issues with my domain DNS related?

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On Thu, 2007-08-09 at 04:30 -0500, Linus Ulrick wrote:
> I have fully qualified domain: afolkey2.net.  It can USUALLY be found
> thusly:
> http://www.afolkey2.net
> 
> Tonight when I came home from work, I started seeing problems with
> pages loading.  Try the following to see what I mean:
> http://www.afolkey2.net/awstats/awstats.pl?config=www.afolkey2.net
> http://www.afolkey2.net/gallery2/main.php

The website didn't load, first go, here.  But the stats page did.  Very
odd.  Both did eventually load, but both slowly.  Though, since the
pages I had to look at were all "generated" things (stats and photo
galleries), that's not uncommon.  Such things are often painfully slow,
in my experience.

It should be noted that making stats public can subject you to referrer
spam:  Spammers linking to your pages, hoping to turn up in your stats,
and hoping that you publish your stats, or publish what refers to you in
some other way, so that you give them free advertising.  You can get
deluged by them, and some quite unsavoury things, too.

> I use the free dynamic dns service from dnsexit.com.  The nameservers
> that they have me point my domain to are as follows:
> ns1.dnsexit.com
> ns2.dnsexit.com
> 
> When I noticed the severe issues described above, I ran "ping" on each
> of those two servers.  The edited results of "ping ns1.dnsexit.com"
> look something like this:
> PING ns1.dnsexit.com (63.223.76.173) 56(84) bytes of data.
> 64 bytes from ns1.dnsexit.com (63.223.76.173): icmp_seq=1 ttl=48 time=417 ms
> 64 bytes from ns1.dnsexit.com (63.223.76.173): icmp_seq=2 ttl=48 time=436 ms
> 64 bytes from ns1.dnsexit.com (63.223.76.173): icmp_seq=3 ttl=48 time=375 ms
> 64 bytes from ns1.dnsexit.com (63.223.76.173): icmp_seq=4 ttl=48 time=349 ms
> 64 bytes from ns1.dnsexit.com (63.223.76.173): icmp_seq=5 ttl=48 time=258 ms

[tim@bigblack ~]$ ping ns1.dnsexit.com 
PING ns1.dnsexit.com (63.223.76.173) 56(84) bytes of data.
64 bytes from ns1.dnsexit.com (63.223.76.173): icmp_seq=1 ttl=55 time=227 ms
64 bytes from ns1.dnsexit.com (63.223.76.173): icmp_seq=2 ttl=55 time=227 ms
64 bytes from ns1.dnsexit.com (63.223.76.173): icmp_seq=3 ttl=55 time=226 ms

I got fairly consistent results for either name server, and fairly
similar ones for the webserver address:

[tim@bigblack ~]$ ping afolkey2.net
PING afolkey2.net (74.134.123.247) 56(84) bytes of data.
64 bytes from 74-134-123-247.dhcp.insightbb.com (74.134.123.247): icmp_seq=1 ttl=132 time=258 ms
64 bytes from 74-134-123-247.dhcp.insightbb.com (74.134.123.247): icmp_seq=2 ttl=132 time=257 ms
64 bytes from 74-134-123-247.dhcp.insightbb.com (74.134.123.247): icmp_seq=3 ttl=132 time=260 ms

It should also be noted that pinging a machine is quite a different
thing than using some other service on it.  You can get good or bad ping
responses that are contrary to how their services respond.  All a ping
test is how they respond to pings.  :-\

I did a "dig" on your domain name, which is just looking up domain
records, the thing that you need to test, and got the following
response:

[tim@bigblack ~]$ dig www.afolkey2.net

; <<>> DiG 9.4.1-P1 <<>> www.afolkey2.net
;; global options:  printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 58276
;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 2, ADDITIONAL: 2

;; QUESTION SECTION:
;www.afolkey2.net.              IN      A

;; ANSWER SECTION:
www.afolkey2.net.       120     IN      CNAME   afolkey2.net.
afolkey2.net.           120     IN      A       74.134.123.247

;; AUTHORITY SECTION:
afolkey2.net.           120     IN      NS      ns1.dnsexit.com.
afolkey2.net.           120     IN      NS      ns2.dnsexit.com.

;; ADDITIONAL SECTION:
ns1.dnsexit.com.        172799  IN      A       63.223.76.173
ns2.dnsexit.com.        172799  IN      A       64.182.102.188

;; Query time: 890 msec
;; SERVER: 192.168.1.2#53(192.168.1.2)
;; WHEN: Thu Aug  9 19:15:18 2007
;; MSG SIZE  rcvd: 143

Which, while being about four times longer to complete (the query time)
than looking up some other domains I just tried (around 200 mS instead
of around 900 mS), is still not terribly slow.  Certainly not as slow as
their webserver was to respond.  So, I'd be more concerned about things
other than their DNS servers.

You probably also want to do some tests on the HTTP server response
time, but I don't have anything to tell you how to test that.  That's
response time, more than download speed.  People will put up with things
taking a little while to finish downloading, so long as they start
fairly promptly.

> when I ran "ping ns2.dnsexit.com" that the server that appeared to be
> the one that was queried is "nd188.dnsexit.com", not "ns2.dnsexit.com"

The same here, but forward and reverse name look ups don't have to match
(a fact often overlooked by some overzealous anti-spam people).  It's
quite likely that whatever does their second name server does more than
just be a name server, and they might have named the device for that
purpose rather than just the name serving feature.

[tim@bigblack ~]$ dig +short  ns1.dnsexit.com
63.223.76.173
[tim@bigblack ~]$ dig +short -x 63.223.76.173
ns1.dnsexit.com.

[tim@bigblack ~]$ dig +short  ns2.dnsexit.com
64.182.102.188
[tim@bigblack ~]$ dig +short -x 64.182.102.188
nd188.dnsexit.com.

However, this is revealing (below).  There's no A record (or any answer)
to trying to find out the IP for their second name server, by the other
domain name.  That could well be a problem, it's just as well that's
their second name server, not the first one.

[tim@bigblack ~]$ dig nd188.dnsexit.com

; <<>> DiG 9.4.1-P1 <<>> nd188.dnsexit.com
;; global options:  printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 50072
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 0

;; QUESTION SECTION:
;nd188.dnsexit.com.             IN      A

;; AUTHORITY SECTION:
dnsexit.com.            1195    IN      SOA     ns2.dnsexit.com. admin.netdorm.com. 2000060701 12000 2400 604800 1200

;; Query time: 15 msec
;; SERVER: 192.168.1.2#53(192.168.1.2)
;; WHEN: Thu Aug  9 19:37:16 2007
;; MSG SIZE  rcvd: 89

You might bring that to their attention, and ask them if they know why
things are running slowly at the moment.

> If nothing else, I THINK I can safely assume that they are having some
> issues on their end.  Nonetheless, do any of you have any suggestions
> about free dynamic DNS services that you have had good fortune with?

I occasionally use no-ip.com, which I see is slightly faster at
responding (667 mS).  But then that's the speed between me and them, and
will be different between them and someone else.  Likewise, with yours.

-- 
[tim@bigblack ~]$ uname -ipr
2.6.22.1-41.fc7 i686 i386

Using FC 4, 5, 6 & 7, plus CentOS 5.  Today, it's FC7.

Don't send private replies to my address, the mailbox is ignored.
I read messages from the public lists.




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