AT&T network issue

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Posted by Kailash12, 08-08-2013, 12:31 PM
Hi,

I am in a web hosting company and we have many clients complaining that they are unable to access the websites from AT&T networks. Our server is in Denver. So far, the clients were unable to access from AT&T networks only.

Does anyone else facing this problem?

Thanks,
Kailash
Posted by alanwoo, 08-08-2013, 12:59 PM
It can be some routing issue, get your client to provide some traceroute so that you can get your upstream provider to fix this issue.
Posted by Kailash12, 08-08-2013, 01:17 PM
This is what I got from one client:

4 26 ms 24 ms * 75.25.192.78
5 * * * Request timed out.
6 * * * Request timed out.
7 29 ms 21 ms 21 ms 12.83.69.29

75.25.192.78 and 12.83.69.29 both belongs to AT&T so my data center provider can't help me to fix it.
Posted by (Stephen), 08-08-2013, 01:25 PM
AT*T is really bad about blocking RBL sites on their network, yes sites..even entire networks.
Posted by JohnCrowley, 08-08-2013, 01:25 PM
It's possible AT&T blackholed your IP or IP range. We had this happen to one of our servers last week, where a compromised Joomla site was being used in a DDOS.

Contact AT&T or try their traceroute telnet server to see if they are blocking your IP right away.
Posted by hostingassets4sale, 08-08-2013, 01:51 PM
You can check out mxtoolbox.com to see what, if any other black lists your IPs are on.
Posted by Ionity, 08-08-2013, 01:59 PM

Quote:

Originally Posted by Kailash12

Hi,

I am in a web hosting company and we have many clients complaining that they are unable to access the websites from AT&T networks. Our server is in Denver. So far, the clients were unable to access from AT&T networks only.

Does anyone else facing this problem?

Thanks,
Kailash

What is the IP of your server?
Posted by JPerkster, 08-08-2013, 02:14 PM
It looks like a couple of servers on our farm are having issues with AT&T as well
Posted by Techno, 08-08-2013, 02:21 PM
We had email issues with AT&T on a site that did't have SPF records. Updating the SPF records didn't help as the IPs were already on their block list. It only resolved itself when we changed IPs and hosts and had good SPF records from the start. The site didn't show on any block lists - it was an internal AT&T thing.
Posted by JonnyQuags, 08-08-2013, 02:47 PM
AT&T may be blocking the IP.

You can test by telneting to route-server.ip.att.net

Try to ping / trace to the IP that people are trying to access, then try another IP on the server. If one pings / the other does not its probably a block.

Send the details to: noc@att.net

Hopefully you get a quick response.
Posted by (Stephen), 08-08-2013, 03:34 PM
Yes it is typically always ATT only and they are very secretive about it all. They won't sent examples of anything be it spam, DDOs etc.
Posted by Kailash12, 08-09-2013, 12:57 AM
All,

Thanks for your suggestions and guideline. I will check them and let's hope it will fix the problem. The one concern I have is why tracert is timing out within their network.

Thanks,
Kailash
Posted by (Stephen), 08-09-2013, 02:15 AM

Quote:

Originally Posted by Kailash12

All,

Thanks for your suggestions and guideline. I will check them and let's hope it will fix the problem. The one concern I have is why tracert is timing out within their network.

Thanks,
Kailash

Because they have their core routers block it.
Posted by Kailash12, 08-09-2013, 02:40 AM

Quote:

Originally Posted by (Stephen)

Because they have their core routers block it.

Thanks for the details.
Posted by SurplusHP, 08-14-2013, 05:04 PM
Yes ATT has blocked the IP my site is hosted on.

My domain is being managed by downtownhost.com and apparently ATT cut off the IP my domain is on.

downtownhost.com said they have asked their upstream providers to contact ATT and get the IP unblocked. ATT blocked the IP and email from the NOC states, because there was a DDOS attack from that IP.

Who knows how long that will take. I've been blocked by ATT for more than a week now.
Posted by Jedito, 08-14-2013, 06:22 PM
ATT is hard to deal like many other big companies are (AOL, Yahoo, etc), the first time that we contacted them, they denied any blockade, sent them about 4 emails for a week without getting any other answer, finally, we got one and they asked to the DC to contact them directly, since apparentely one of the IPs of our servers was part of a DDOS to theirs, that's very odd, since I was checking all the traffic logs of that server I don't see any peak of traffic in over a month.

Anyway, we contacted to our DC asking them to contact to ATT.
Posted by (Stephen), 08-14-2013, 06:51 PM
Jedito

The reason for block on one of our IPs had to be minor as one of the server that was blocked had a peak of only 4.5mb/s the entire month!