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Matthew
Premium Member
join:2001-08-03
Emmett, ID

1 edit

Matthew

Premium Member

Some DNS changes

The AT&T DSLReports team has received notification that the company is switching DNS to an any cast DNS plan using only two DNS IP's across the network. The volume of DNS clusters is not going down, but their addresses are. The group working the change is slated to complete turning down the legacy DNS IP's by year's end, and regionally one by one.

I have been asked to get the word out on this site that this change is going on, as someone who is working the change noticed discussion on this site around hard coding some of the legacy DNS addresses that will be turned down.

If you are either a static customer or have other wise hard coded your DNS entries to the legacy DNS IP's, please start using:

68.94.156.1 and 68.94.157.1


instead of the old IP's at your earliest convenience. Keep in mind that we probably will not get a list of when any particular legacy DNS IP will be turned down, so the sooner you make the change the better.

Any questions, please feel free to reply to this post and I will be sending this thread to the person who let me know about the up and coming changes.

{Added emphasis on new IPs. ~F}

d_l
Barsoom
MVM
join:2002-12-08
Reno, NV

d_l

MVM

Have all the new DNS servers that are intended to be installed been completed? Meaning will the locations (and latencies) shown by a tracert to those IPs stay the same for the foreseeable future?
Enlightener
join:2006-01-28
Cedar Park, TX

Enlightener to Matthew

Member

to Matthew
If everyone is on PPPoE or DHCP ( including the fake static IP's ) then this really should be a non-issue. Let the infrastructure manage itself.

Derwood2
Wherever you go, there you are
Premium Member
join:2003-01-21
Dayton, OH

Derwood2 to Matthew

Premium Member

to Matthew
How will this affect those of us that have PTR records with SBC for doing our own reverse DNS?

justjact
Skynet
Premium Member
join:2002-07-05
Leavenworth, KS

justjact to Matthew

Premium Member

to Matthew
Thanks For the info.
macrat8
join:2005-02-28
Dundee, IL

macrat8 to Matthew

Member

to Matthew
i REALLY need your help - i'm trying to figure out if these DNS changes would explain why we've been having trouble reestablishing a connection every morning for about a week?



we've got SBC DSL (Speedstream 5360 Ethernet ADSL Modem) and connect our iMac (OS 10.4.5) via PPPoE. (network port config: built-in ethernet, connect using PPPoE)


every morning we've lost our connection. trying to re-connect results in PPPoE connection failed, no route to host


so, i turn off the modem, disconnect the cable from the box (and sometimes i disconnect it from the computer) wait about a minute, then reinsert the cable and turn on the box.


turning off the box results in couldn't find PPPoE, which seems to start the network assistant application.


i'm taken through steps to establish a connection (since this started happening, we're up to about 9 configuration settings). after i've finished, it attempts to connect. sometimes it does, but lots of times it doesn't work the first time: it can't find the PPPoE server or something.


i usually have to repeat the procedure a few times (turning off the box, network assistant, etc) before finally re-establishing a new connection.


i hope i've described things clearly enough for you to maybe be able to determine if this daily need to re-establish a connection thing is due to the DNS changes? i read someone's reply:
If everyone is on PPPoE or DHCP ( including the fake static IP's ) then this really should be a non-issue. Let the infrastructure manage itself.

- but i think it might be the issue with us even though we do connect via PPPoE.

please advise! thanks very much,
carrie

owlhooter
Premium Member
join:2002-01-19
Wylie, TX

owlhooter

Premium Member

DNS is going to have absolutely nothing to do with your authentication failures. The error you are having would more than likely be something either specific to your equipment (modem, computer) or the line itself. Might want to create a regular post outside of this topic and see if anyone can help you out with that.
owlhooter

owlhooter to Derwood2

Premium Member

to Derwood2
This will not affect PTR records at all as these servers are just the resolvers for customers connections. All this change does is to help provide more redundancy in the DNS system and allow setting to be the same across all of the AT&T/SBC regions
owlhooter

owlhooter to d_l

Premium Member

to d_l
Yes, all are in place right now that are intended to be installed at this time.

d_l
Barsoom
MVM
join:2002-12-08
Reno, NV

d_l

MVM

Thanks for that info. So there will be a reduction in the DNS server levels in some areas, ie., there are network centers that currently have servers which will not have servers in the future.

I've also noticed that the secondary DNS server of the new system is supplied by a server in the same physical location as the first, unlike the arrangement for the old servers. Will the anycast system, automatically re-route to the next nearest available DNS servers should the connection to the nearest DNS server pair be disrupted for some reason? In other words, will this any cast system provide a network-wide redundancy to the server network? Thanks.

koma3504
Advocate
Premium Member
join:2004-06-22
Granbury, TX

koma3504

Premium Member

so could this also be a DNS # 68.94.156.30
wierdo
join:2001-02-16
Miami, FL

wierdo to d_l

Member

to d_l
d_l, the anycast system works much (well, exactly if it's implemented correctly) like the .org TLD servers. 68.94.156.1 and 68.94.157.1 are advertised by many different routers. When you send a request to 68.94.156.1 or 68.94.157.1, it goes to the closest DNS server SBC has. If that goes down, presumably it is no longer advertised in the routing protocol, causing further packets to those addresses to go to the next closest and so on until they all die.

All this really does is make it so any redundancy is transparent, and everyone will automagically have their DNS requests routed to somewhere close by.

Look up anycast, it's pretty neat, and it's being used for lots of things these days, including some of the root DNS servers as well. (f, at least, IIRC)

In the end, it's just a bunch of routers advertising the same IPs, just like a multihomed network does in the global BGP table. The automatic re-routing is the entire point of using anycast.

d_l
Barsoom
MVM
join:2002-12-08
Reno, NV

d_l

MVM

That's the sort of explanation I was asking about, but more to be presented on an "official" basis. That sort of official info makes for good FAQ material.

Derwood2
Wherever you go, there you are
Premium Member
join:2003-01-21
Dayton, OH

Derwood2 to owlhooter

Premium Member

to owlhooter
Thanks, Owlhooter.. I was pretty sure you guys kept those DNS servers separated away from normal recursive DNS queries. I just wanted to make sure..

biff420
Premium Member
join:2002-01-26
Vallejo, CA
·Comcast XFINITY

biff420 to Matthew

Premium Member

to Matthew
said by Matthew:

The AT&T DSLReports team has received notification that the company is switching DNS to an any cast DNS plan using only two DNS IP's across the network.
Is it just me, or do these new DNS servers seem SLOW!
My router configured itself to one of the DNS servers
and something I never had with DSL appeared. Lag

When I used to click DSLR it was there instantly.
Now it takes 4-6 seconds before the browser acknowledges
and loads. Not just DSLR, but every site now has this
cable-like lag.

back to 4.2.2.2

d_l
Barsoom
MVM
join:2002-12-08
Reno, NV

d_l

MVM

Where are your servers actually located? SF? After a lot of dig testing, I'd say the new ones in Sacramento are no slower than the old one in Reno if you account for the extra packet latencies due to the distance.

When the new servers were first started operating back in Dec., dig testing sometimes showed 100-200 ms delays, but that settled out soon enough.

biff420
Premium Member
join:2002-01-26
Vallejo, CA
·Comcast XFINITY

biff420

Premium Member

said by d_l:

Where are your servers actually located? SF? ...
Sacramento is the primary, and San Francisco is the Secondary.
I entered the new DNS servers in the router manually. The lag
began today. I reset the router to get DNS automatically, and it put me on the current servers. (Sac. & SF)

My speeds are fine after getting on a new router.
This lag deal is new, and hopefully temporary.

aaparkr
Premium Member
join:2000-08-13
Edmond, OK

aaparkr

Premium Member

said by biff420:

said by d_l:

My speeds are fine after getting on a new router.
This lag deal is new, and hopefully temporary.
It was transparent to me. I just checked and my router has the new DNS. No noticible difference in the speed to any of the sites I usually frequent (www.auburnmeadows.org, aaparker.net for example)...

Tony
gregoliver0
join:2006-04-08
Richardson, TX

gregoliver0

Member

I have had trouble recently with long name resolution...

IE - aaaaaaaa.bbbbbbbb.cccccccc.ddddddddd.domain.com

I assumed it was my linksys, so I deleted it from my resolv.conf, but the 2 remaining could not 68.94.15[6,7].1 either. I had to open a hole in our firewall @ work to allow myself to use our corp dns servers.

Today it is working fine. It is always the same server/IP I'm trying to lookup. It's funny - the host I am visiting is our NOCC traffic screen, so the page refreshes every 5 minutes. It will work for hours and then die.. You would think firefox would cache it..

Anyone seen issues like this since the cutover - it has only been happening for ~2 weeks.

Thanks,

Greg
DNSguy
join:2006-04-09
Saint Charles, MO

DNSguy to Matthew

Member

to Matthew
The anycast IPs are simply additional addresses mapped to existing DNS clusters across the network. So say your DSL service is terminated on a BRAS in Richardson, TX and you were using 151.164.1.8 for DNS. If you switch to the anycast IPs your DNS requests will still go to the same servers, only the access method / front end VIP has changed. Another thing to keep in mind is that we switched PPPoE logins to the anycast IPs in January. If you accept DNS settings from the network you have been using anycast since then.

Jan Janowski
Premium Member
join:2000-06-18
Waynesville, NC

2 edits

Jan Janowski to Matthew

Premium Member

to Matthew
Thanks!!! Made the changes!
Noting after changes that I have fewer retry's...

tonyfer2
join:2002-08-14
Elizabeth, NJ

tonyfer2 to DNSguy

Member

to DNSguy
just this at&t and the NSA
Markeaux
join:2003-07-12
Austin, TX

Markeaux to Matthew

Member

to Matthew
I have true static ip's. My ping times to the new dns servers are about 12ms, but the ping times to the original dns servers I was told to use are about 7ms.

I know ping may not be the best measure for access times; but I just wanted to make sure I should be using the new dns servers. Plus, if one did not read this forum would ATT be emailing out the new dns server info or otherwise somehow informing us of the change?
man00
join:2003-07-25
united state

man00

Member

I changed mine back to where they were, IMO browsing seems faster.
Markeaux
join:2003-07-12
Austin, TX

Markeaux to Matthew

Member

to Matthew
I changed mine back, too ... seems faster ... maybe it is too soon for our areas.
eatabagel
join:2006-05-20
Santa Cruz, CA

eatabagel to Matthew

Member

to Matthew
I wonder if this is a related problem because I've been having trouble with my DNS for the past two months.

I'm in Santa Cruz, CA and I have a dynamic IP. However regardless of whether I use the two DNS servers or use the DHCP assigned settings, I have trouble reaching some of my favorite sites. For instance, gothamist.com, among other sites, gets a "failed to open page" in Safari. Did a traceroute and I couldn't get a route to host. So something weird's going on.

The only way for me to reach it is to use a web proxy provided by my university. I really don't understand why I'm having this problem because nothing substantial has changed with my setup (Mac and a Netgear router). I can reach like 4/5 of the internet , but not some sites.

Any pointers to possible solutions would be appreciated. Thanks.
man00
join:2003-07-25
united state

man00 to Markeaux

Member

to Markeaux
Mine had like a couple of seconds delay while clicking on link. No delay after changing back.
DCSholtis
join:2006-05-28
Independence, OH

DCSholtis to macrat8

Member

to macrat8
I'm having the same problem at macrat. (Speedstream 4100 DSL Modem) connected to an Airport Extreme (Set to PPPoE) and 2 iMacs and a Powerbook connected using DHCP. Problems began 2 weeks ago. I have had techs over a few times and have made endless calls with no solution in site. Anyone have any ideas? Thanks.
DCSholtis

DCSholtis to macrat8

Member

to macrat8
Im having the same problem at macrat. (Speedstream 4100 DSL Modem) connected to an Airport Extreme (Set to PPPoE) and 2 iMacs and a Powerbook connected using DHCP. Problems began 2 weeks ago. I have had techs over a few times and have made endless calls with no solution in site. Anyone have any ideas? Thanks.
krobar
Is this thing on?
join:2002-09-15
Columbus, OH

krobar to Matthew

Member

to Matthew
sorry for the thread bump, just wondering if there's been any problems lately, I'm getting a lot of timeouts lately and slow loading at random times, but speed tests keep reporting everything ok, and torrents and what not don't slow down.