SomeFool
join:2008-03-24
Metro Chgo
moderated:
April 27th, @08:09AM
|  Ongoing AT&T DNS server problems?
I get my DSL service from AT&T through Chicago redback-12. Occasionally I can't connect to the net because my system fails to find a DNS server. It happened again last evening and the problem re-occurs just often enough to be annoying. Without further adoo I turned the box on this morning and everything works again. It appears my getting a good night's sleep somehow fixes the servers. 
I've discussed this with AT&T L2 support and... well. Last time I was directed to hard code the DNS server ip's into my 2-Wire 1701. I thought that wouldn't fix things and it didn't. The tech's always want me to dig into my router, but as Rocky used to say "Aw gee Bullwinkle, that old trick never works". 
My questions are this. Who's in charge of the DNS servers? From a systems standpoint, is this AT&T stuff or Yahoo stuff? Help me understand how the parts of this system are supposed to work together.
Edit: My system couldn't find the eMail servers either.
Mod: Topic modified to replace Proxy with DNS |
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nwrickert
sand groper
Premium,MVM
join:2004-09-04
Geneva, IL
 ·AT&T Midwest
| Re: Ongoing AT&T Proxy server problems?
I occasionally have that problem with my laptop, but never with my desktop.
The difference:
On my desktop I run my own DNS servers when running linux. I have the AT&T DNS servers hard coded into my windows system (applicable when running Windows).
On my laptop, I use DHCP to get IP address and DNS servers.
Here is what I think is the problem, though I am not certain:
The modem/router acts as a DNS forwarder, and forwards the DNS requests to the AT&T DNS server. This normally works fine. However, the modem/router only forwards UDP requests for DNS. The trouble with the yahoo/ATT home page and mail servers, is that the DNS response is rather long. A long answer to a DNS udp query is sometimes truncated, and the client follows up with a tcp query. Since the modem/router does not handle tcp queries, this fall back to tcp never works.
Incidently, this DNS forwarding is a common practice in routers, not the 2Wire that you are using.
--
AT&T dsl; Westell 327w modem/router; SuSE 10.1; firefox 2.0.0.13 |
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NormanS
Premium,MVM
join:2001-02-14
San Jose, CA
·Pacific Bell - SBC
| reply to SomeFool
said by SomeFool  :My questions are this. Who's in charge of the DNS servers? From a systems standpoint, is this AT&T stuff or Yahoo stuff? Help me understand how the parts of this system are supposed to work together. Yahoo! is just a content provider. Provisioning, and transport are handled by AT&T Internet Services (ATTIS). Including DNS.
What DNS server IP addresses do you get when you obtain your IP address automatically? Just curious; I've seen some still pulling specific servers instead of the "Anycast" DNS servers. I thought the whole ATTIS system was moving to the "Anycast" servers.
For reasons I can't fathom, AT&T Midwest seems to have more troubles with DNS than the rest of the system.
--
Norman
~Oh Lord, why have you come
~To Konnyu, with the Lion and the Drum |
|
SomeFool
join:2008-03-24
Metro Chgo | Ok thanks, then I'm not alone having these occasional DNS problems. It would be refreshing if the AT&T tech's would simply say -- Nevermind, the problem is ours, it's not on your end.
At present my DNS's are at 68.94.156.1 and 68.94.157.1 |
|
NormanS
Premium,MVM
join:2001-02-14
San Jose, CA
·Pacific Bell - SBC
| said by SomeFool :At present my DNS's are at 68.94.156.1 and 68.94.157.1 Those are the "Anycast" IP addresses; same as mine. Trace route varies by location because of the nature of the way that "Anycast" works. It is supposed to be an improvement. "Anycast" works very well for Level 3 (4.x.x.x) and OpenDNS. I've not seen a lot of problems reported with the ATTIS "Anycast" DNS servers in AT&T Northeast, AT&T Southwest, or AT&T West. I have had no trouble in the S.F. Bay Area (AT&T West). The most problems I have seen reported with ATTIS DNS service have been in AT&T Midwest.
--
Norman
~Oh Lord, why have you come
~To Konnyu, with the Lion and the Drum |
|
schja01
I need to get a life.
Premium,MVM
join:2000-04-27
Morton Grove, IL
clubs:   | reply to SomeFool
Re: Ongoing AT&T DNS server problems?
A looooong time ago I scrapped AT&T's (and in my cast Comcast's too) DNS servers and hard code two Level3 servers. They are fast and reliable. I haven't looked back since changing them.
Personally I use these:
4.2.2.2
4.2.2.1 |
|
SomeFool
join:2008-03-24
Metro Chgo
| said by schja01 :Personally I use these: 4.2.2.2 4.2.2.1 After more slow DNS response this morning I switched. The response has been very good all day. |
|
NormanS
Premium,MVM
join:2001-02-14
San Jose, CA
·Pacific Bell - SBC
| Just out of curiosity, you might want to check this thread:
»[Software] Beta testers wanted: ns_ bench :)
Grab the utility and compare the ATTIS DNS servers with the Level 3, and the OpenDNS servers. As I have stated, all three use "Anycast" technology. I don't know if OpenDNS has finally got there Midwest server farm up, or if you will be testing their East coast servers.
Not saying you should change back, just check the comparative performance.
--
Norman
~Oh Lord, why have you come
~To Konnyu, with the Lion and the Drum |
|
koma3504
Advocate
Premium
join:2004-06-22
North Richland Hills, TX
| Nameserver Response Time (ms)
min/avg/max/stdev/retries
151.164.1.8 failed
68.94.156.1 failed
151.164.30.105 failed
151.164.8.201 failed
208.67.222.222 failed
adns_init: Resource temporarily unavailable
yahoo.com failed
C:\ns_bench\win32>ns_bench.exe 208.67.222.222
Nameserver Response Time (ms)
min/avg/max/stdev/retries
208.67.222.222 failed
C:\ns_bench\win32>
all i get with this tool is this DSL has been really funny.
--
† Koma †
If YOu Don't Think It's Possable!! It's Acually A Reality!!The best way to predict the future is to invent it. Alan Kay!!
Ya Don't Know The signal Till Ya Ride It!!
Voice Break's There's Trouble!!!! |
|
d_l
Barsoom
Premium,MVM
join:2002-12-08
Reno, NV
| Nameserver Response Time (ms)
min/avg/max/stdev/retries
4.2.2.1 17.01/20.22/24.45/2.95/0
4.2.2.2 16.34/17.98/22.49/2.28/0
66.218.44.5 17.01/20.33/24.50/3.33/0
66.218.44.90 18.04/20.90/25.09/3.21/0
66.51.206.100 25.78/27.18/31.74/2.29/0
66.51.205.100 64.88/82.86/144.06/30.70/0
208.67.222.222 16.49/18.70/21.68/2.18/0
208.67.220.220 16.65/17.80/21.43/1.83/0
»SBC DSL FAQ »How do I test DNS lookup latency with ns_bench?
Do you have a software firewall that is blocking adns operation? |
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koma3504
Advocate
Premium
join:2004-06-22
North Richland Hills, TX | Well zone alarm ask permission and i give it. |
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David
Last man standing
Premium,VIP
join:2002-05-30
Granite City, IL
clubs: | You guys still having problems with DNS? Post a tracert to the DNS and let's take a look.
Also the NS_bench is a good test too. |
|
deblin
Dark Side of the Moon
Premium,MVM
join:2001-09-01
Middletown, DE
 ·Verizon FIOS
 ·Comcast Workplace
·DSL EXTREME
| reply to koma3504
said by koma3504 :Well zone alarm ask permission and i give it. I'm not familiar with zone alarm, but have you tried (temporarily) disabling it entirely? How do you "allow" ns_bench.exe to work? Do you specifically allow the binary, which allows all access, or do you specify a specific port/ports? If so, make sure you are allowing udp port 53, NOT tcp. Although the DNS protocol will fall back on tcp for large queries, the queries ns_bench is performing are going to use udp, not tcp.
--
Hello...is there anybody in there? |
|
quaker23
join:2001-12-27
Cleveland, OH | reply to SomeFool
i use opendns servers there fast and updates get put in place very quickly.
sbc dns servers have like a 30 sec delay on them and i cant have that or sometimes they cant resolve any hosts at all |
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NormanS
Premium,MVM
join:2001-02-14
San Jose, CA
·Pacific Bell - SBC
| said by quaker23 :i use opendns servers there fast and updates get put in place very quickly. sbc dns servers have like a 30 sec delay on them and i cant have that or sometimes they cant resolve any hosts at all OpenDNS is not quite as good as the ATTIS DNS servers, as tested from San José, California; but slightly better than the Level 3 DNS servers.
So far, the only person to post any successful 'ns_bench' results has been a fellow AT&T Westerner. I am curious about the results from an AT&T Midwesterner.
--
Norman
~Oh Lord, why have you come
~To Konnyu, with the Lion and the Drum |
|
parkut
Crunch Addict
Premium
join:2001-12-15
Harrison Township, MI
clubs:
·WOW Internet and C..
·AT&T Midwest
| reply to SomeFool
from dsl.sfldmi.sbcglobal.net
Nameserver Response Time (ms)
min/avg/max/stdev/retries
68.94.156.1 15.67/17.11/21.63/2.27/0
68.94.157.1 15.18/16.06/16.65/0.58/0
4.2.2.1 22.45/22.96/23.41/0.32/0
4.2.2.2 22.39/24.44/29.25/2.46/0
208.67.220.220 40.49/40.82/41.06/0.19/0
208.67.222.222 40.03/41.74/45.48/1.94/0
--
Hello, my name is Bill and I'm a crunchaholic...
Proud to be the current host of Crunchenstein #1, #3, #5, and Foldy #3 |
|
ddeisz
join:2002-05-14
Batavia, IL
·AT&T Yahoo
| reply to NormanS
Here is one of the representative ns_bench results from my home. 192.168.33.15 is my own DNS server.
Nameserver Response Time (ms)
min/avg/max/stdev/retries
4.2.2.1 14.15/14.47/14.70/0.23/0
4.2.2.2 13.85/14.24/14.72/0.32/0
68.94.156.1 15.65/inf/570.86/nan/5
68.94.157.1 failed
208.67.220.220 40.17/40.35/40.48/0.11/0
208.67.222.222 39.64/40.00/40.77/0.41/0
192.168.33.15 2.07/2.30/2.65/0.22/0 |
|
NormanS
Premium,MVM
join:2001-02-14
San Jose, CA
·Pacific Bell - SBC
| Thank you. I notice that OpenDNS it at 40 ms, or so. Looks like they haven't brought their Midwest servers online, yet.
The secondary ATTIS DNS server failed; first time I've seen that in an 'ns_bench' result (ATTIS DNS failure). Certainly looks like trouble. I wonder why only in AT&T Midwest?
--
Norman
~Oh Lord, why have you come
~To Konnyu, with the Lion and the Drum |
|
SomeFool
join:2008-03-24
Metro Chgo
| reply to SomeFool
For most of this morning my system found no DNS... again.
I was using pri 4.2.2.1 and sec 4.2.2.2. A ping to 4.2.2.1 timed out, while 4.2.2.2 had normal 13 to 17 msec. response times. I set the router back to automatically acquire a DNS, and it works... but for how long?
This is easy enough to fix when it happens, but still a pita. Like AT&T gave the Slowski's tool belts and turned them loose at DNS central? |
|
NormanS
Premium,MVM
join:2001-02-14
San Jose, CA
·Pacific Bell - SBC
edit:
May 3rd, @07:31PM
| said by SomeFool :For most of this morning my system found no DNS... again. I was using pri 4.2.2.1 and sec 4.2.2.2. A ping to 4.2.2.1 timed out, while 4.2.2.2 had normal 13 to 17 msec. response times. I set the router back to automatically acquire a DNS, and it works... but for how long? This is easy enough to fix when it happens, but still a pita. Like AT&T gave the Slowski's tool belts and turned them loose at DNS central? I am not aware of anything that AT&T is doing that would cause problems when using the Level 3 DNS servers. Or did I misunderstand what you are saying?
If you had set the DNS servers to the Level 3 IP addresses, and then had a DNS failure, something else is going on than an AT&T DNS problem.
--
Norman
~Oh Lord, why have you come
~To Konnyu, with the Lion and the Drum |
|
