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AT&T Routing Issues

BlindedByScience said:
I don't have a dog in the fight, but everyone with even a small bit of computer savy should be running OpenDNS. For home users, there's nothing to download, and it's free.

I've been running it for a couple years, and it really works fantastically. Very easy to recommend.
Click to expand...

Thanks Tom! I've been wanting something like this for a long time, but never got around to looking into it. I work from home and my ISP's DNS servers always seem to be unreachable at the most inconvenient times. This is great.
 
Definately thanks for the OpenDNS suggestion. Uverse/techconnect's support was driving me batsh*t crazy last night. 2 hours of explaining the issue was widespread, they STILL kept trying to troubleshoot MY router.
 
Do you know what IPs are being returned by AT&T's DNS? AT&T has a looking glass router at route-server.ip.att.net. You can telnet into there and see what the BGP routes are for the returned IP addresses. Maybe compare that to other public looking glass routes.
 
Hi John,

Here are the results. It's not even making it out of AT&T's network.



route-server>traceroute cigarpass.com
Translating "cigarpass.com"...domain server (12.0.1.23)

Translating "cigarpass.com"...domain server (12.0.1.23) [OK]

Type escape sequence to abort.
Tracing the route to cigarpass.com (74.204.174.87)

1 gateway.cbbtier3.att.net (12.0.1.202) [AS 7018] 4 msec 4 msec 0 msec
2 * * *
3 * * *
4 * * *
5 * * *
6 * * *
7 * * *
8 * * *
9 * * *
 
Rod, interesting read as I have zero connections through AT&T. My issue is through Mediacom, my ISP.

Odd thing, I could get on yesterday in the morning, but by the late afternoon... Nada! I'm stuck accessing CP via my Verizon phone.
 
Traceroute can stop for any number of reasons. The AT&T router won't let me choose a source address for the traceroute, either, so who knows what it's using.

All I can do is confirm this seems to be an AT&T issue. Using Comcast's looking glass, they connect through the same networks to get to your IP: Limelight (AS22822) and then VirtaCore (AS14383), and a ping works from Comcast, but not from AT&T. Comcast is the only other network I could find connecting through Limelight. A ping/trace from Limelight works, also.

I can't find a VirtaCore looking glass to see how they get back to AT&T addresses. Asynchronous routing _shouldn't_ cause an issue, in theory, but it always does in my experience. If you trace back to route-server.ip.att.net from the CP server, do you see it going through Limelight AS22822?

ETA: Mediacom doesn't have a looking glass, either, but they peer with AT&T AS7018, so if the CP route is going to AT&T, it would have the same issue, I imagine.
 
Rod,
I was able to get on at home on my iPhone via WiFi just before I left for work this morning. I think I mentioned that I couldn't get openDNS to work. I guess it was only a temporary fix for some others too. I know moving the site was a major pain but hopefully AT&T will get their DNS server problems fixed and you'll never have to do it again.

Thank You for all that you do...
Larry
 
it seems I cant get in on my Verizon phone
I'm getting" your DNS has not received the update please try back later.
what update?
 
So last night when I got in on my phone it was via 4G, but now on LTE it's back to it's old tricks.

Going to talk to a tier 2 support person tonight as last night didn't fix anything.
 
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