AT&T Uverse/DSL Network Engineer DNS question

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1

Hi,

Can a AT&T Uverse/DSL Network Engineer answer a question about the DNS
server IPs that are handed out to customers please? I am currently testing from
a Florida IP. Can you please let me know if all Uverse and DSL customers
across the United States only use these 2 IPs as their primary and secondary
DNS servers?

68.94.156.1

68.94.157.1

We
provide services based on IP GEO-location. Since the 2 recursive resolvers
below are registered in Texas every DNS query for any of our records return
results that are intended for IPs in that region. In other words, users on the
east coast would actually resolve to a central part of the US or west coast IP.

Thanks
in advance,Tim

2

These appear to be an anycasted service, as I reach different destinations
based on my source address.

Hopefully each deployment has unique origin IPs for their recursive queries.

I would recommend against looking at RIR registration data to determine IP
location. There's often little to no correlation, there.

--j

3

These appear to be an anycasted service, as I reach different destinations
based on my source address.

Hopefully each deployment has unique origin IPs for their recursive
queries.

Just confirmed this. As these resolvers traverse and query your servers,
they'll have different source IPs, depending on the regional resolver.

Return differentiated DNS responses, based on that.

--j

4

Here in Orange County, CA I've got a /28 with Uverse Residential with the
same DNS servers as mentioned below.

FYI

5

Thanks for checking guys. I checked RIR registration and they have those 2 IPs registered in
Texas. I have read that AT&T uses anycast for name resolution for
Uverse/DSL customers. I can only check from my account in Florida and
the DNS query responses so far resolve as if I were in the Central
United States because the recursive resolvers are registered in Texas, I
as far as I can tell.

I just need to know if these are the only DNS server IPs they hand out to their Uverse/DSL customers.

Thanks,
Tim Haak