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fxsapp

join:2005-10-03
Fargo, ND

[DNS] Comcast DNS connectivity issues

My ISP: Comcast Cable Internet

Location: Fort Collins, CO- Colorado Springs, CO

Speedtest: »stage.results.speedtest.comcast.···1732.png

OS: Win7

Modem: Cisco DPC3008 (wired, no wireless)

No Active Anti-Virus Program running

My issue is not a current one, but I am looking for advice for when it may happen again- during the first week I had service, my connection dropped and my modem reset, when it reset all of the lights were normal, however the error I was getting was "windows cannot communicate with primary dns server" My friend who lives in Colorado Springs also had this issue with their first day of service. We are both using the default DNS servers that comcast provides-
»dns.comcast.net/dns-ip-addresses.php

Last night, this happened to my friend and their service was down for about 2 hours, with the same error that I had. Is this something that is beyond our control or is there something we can do?

Here is what we both have done to try to restore service when it went down.

Proper power cycling equipment
ipconfig /flushdns /registerdns /release /renew
reset TCP/IP
change DNS servers to OpenDNS or Google's DNS
Repair connection through Windows
Disable/Re-enable adapter

any input on this is appreciated thank you



tshirt
Premium,MVM
join:2004-07-11
Snohomish, WA
kudos:4
Reviews:
·Comcast

said by fxsapp:

change DNS servers to OpenDNS or Google's DNS

Did that work? (I'm guessing not, or you wouldn't need to post here.
I think that shows the message was a symptom rather than the cause of the outage, and not really a problem.
A 2 hour outage implies major damage, major problems, or major upgrades and are very rare in most areas.
The best bet if a power cycle doesn't fix it and the lights and signal levels look normal is to call in to determine if any of those are happening.

fxsapp

join:2005-10-03
Fargo, ND

1 edit

thank you that is what I thought- if anyone else has any ideas just throw them my way if you don't mind- seems to be a fairly common situation I may face

anyone else have an opinion for this?


Dawson46

join:2012-07-27
Greensburg, PA
reply to fxsapp

We have Extreme 105 and Comcasts DNS has been a major issue with us so we did the Google DNS.



EG
The wings of love
Premium
join:2006-11-18
Union, NJ
kudos:9

said by Dawson46:

We have Extreme 105 and Comcasts DNS has been a major issue with us so we did the Google DNS.

What would one have to do with the other ?


NetFixer
Freedom is NOT Free
Premium
join:2004-06-24
The Boro
Reviews:
·Cingular Wireless
·Comcast Business..
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reply to fxsapp

From the information you posted, I am going to assume that you have a single Windows 7 PC directly attached to your cable modem.

I suspect that the problem you saw had nothing directly to do with DNS, and that the real problem was just that your Internet connectivity was not yet fully operational immediately after the power outage ended.

If it happens again, do an "ipconfig /all" to get the PC's IP address, and the gateway and DNS server IP addresses. Then (assuming that you do have an Internet IP address and not a private 192.168.x.x or 169.254.X.X IP address) try to ping the gateway IP address and the DNS server IP addresses. That should tell you if you actually do have Internet connectivity. If you can't reach the gateway or the DNS servers, nothing else is going to help until Internet connectivity is restored.
--
We can never have enough of nature.
We need to witness our own limits transgressed, and some life pasturing freely where we never wander.


grimmwit

join:2010-01-19
New Boston, NH
reply to Dawson46

said by Dawson46:

We have Extreme 105 and Comcasts DNS has been a major issue with us so we did the Google DNS.

With those speeds provisioned, you may want to reconsider using GoogleDNS (or any other DNS provider for that matter). I tripped over the fact that using alternate DNS providers results in you being connected to the wrong CDN (Content Distribution Networks). This can result in your downloads being much slower that expected.

When I was using Google or OpenDNS, my best download speeds were about 1MB / sec. Switched back to Comcast, was getting as high as 6MB / sec. See this article for a full explanation -
»apcmag.com/why-using-google-dns-···idea.htm
(There are many other articles out there - but this one seems to explain it well)


JJJohnson

join:2001-08-25
Fort Collins, CO
reply to fxsapp

Just how bad _are_ Comcast's DNS servers? I switched to them briefly today. The two servers assigned through DHCP were 75.75.75.76 and 75.75.75.75. While using them I was getting at least 20% failed DNS lookups just doing typical web browsing. Jeezus, even www.google.com failed.

I switched back to using my own local caching DNS server (with OpenDNS servers as backups) and the problems disappeared. I find it almost hard to believe Comcast's servers are that godawful bad, even though I stopped using them 12 years ago for exactly the same reason.



EG
The wings of love
Premium
join:2006-11-18
Union, NJ
kudos:9
reply to fxsapp

Hmmm.. Never a problem with them here.. YMMV.



Mike Wolf

join:2009-05-24
Beachwood, NJ
kudos:3
reply to JJJohnson

Hmm you're having trouble with the DNS servers? I've been using them exclusively since before they first switched over to the Anycast DNS system, and I've really never had any problems. I hope this isn't a sign of bad times coming.



JJJohnson

join:2001-08-25
Fort Collins, CO

Is everyone assigned the same DNS servers, or are they regional? I may try it again to see whether something else was going on.



Mike Wolf

join:2009-05-24
Beachwood, NJ
kudos:3

According to Comcast's DNS page the DNS addresses 75.75.75.75 and 75.75.76.76 (as well as the two IPv6 addresses) are distributed across many servers via Anycast for redundancy and reliability, so thats a hard question to define within the parameters of local, regional, and national. Every Comcast customer within the nation receives the same DNS addresses by default and the nodes are geographically dispersed.


andyross
Premium,MVM
join:2003-05-04
Schaumburg, IL
reply to fxsapp

To check exactly where your DNS is going, you have to run a TRACERT or TRACEROUTE to one of the DNS addresses and see if there are any obvious city/state names.

I'm near Chicago, and mine goes to cdns01.comcast.net for 75.75.75.75, and cdns02 for 75.75.76.76. 75.75 goes into area4 Chicago. 76.76 goes to westalndrdc.mi.michigan.



NetFixer
Freedom is NOT Free
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join:2004-06-24
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Reviews:
·Cingular Wireless
·Comcast Business..
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said by andyross:

To check exactly where your DNS is going, you have to run a TRACERT or TRACEROUTE to one of the DNS addresses and see if there are any obvious city/state names.

I'm near Chicago, and mine goes to cdns01.comcast.net for 75.75.75.75, and cdns02 for 75.75.76.76. 75.75 goes into area4 Chicago. 76.76 goes to westalndrdc.mi.michigan.

And that is only a partial picture of how your connection interacts with Comcast's Anycast network. For example, here is my traceroute results to 75.75.75.75 and 75.75.76.76:


C:\>tracert 75.75.75.75
 
Tracing route to cdns01.comcast.net [75.75.75.75]
over a maximum of 30 hops:
 
  1    <1 ms    <1 ms    <1 ms  host6.dcs-net.net [75.146.8.46]
  2    25 ms    29 ms    19 ms  96.191.160.1
  3     9 ms    10 ms     9 ms  xe-4-0-0-0-sur01.murfreesboro.tn.nash.comcast.net [68.85.50.125]
  4    11 ms    15 ms    10 ms  xe-3-1-2-0-ar03.nashville.tn.nash.comcast.net [68.85.174.17]
  5    21 ms    72 ms    20 ms  so-3-0-0-0-ar01.b0atlanta.ga.atlanta.comcast.net [68.85.109.245]
  6    27 ms    22 ms    23 ms  te-8-3-ur01.s3ndigital.ga.atlanta.comcast.net [68.86.107.18]
  7     *        *       22 ms  cdns01.comcast.net [75.75.75.75]
 
Trace complete.
 
C:\>tracert 75.75.76.76
 
Tracing route to cdns02.comcast.net [75.75.76.76]
over a maximum of 30 hops:
 
  1    <1 ms    <1 ms    <1 ms  host6.dcs-net.net [75.146.8.46]
  2    32 ms    10 ms    69 ms  96.191.160.1
  3    10 ms     9 ms     9 ms  xe-4-0-0-0-sur01.murfreesboro.tn.nash.comcast.net [68.85.50.125]
  4    26 ms     9 ms    10 ms  xe-11-2-0-0-sur02.murfreesboro.tn.nash.comcast.net [68.86.176.110]
  5    12 ms    11 ms    11 ms  xe-2-1-1-0-ar01.goodslettvll.tn.nash.comcast.net [68.86.176.53]
  6    23 ms    19 ms    28 ms  pos-2-2-0-0-cr01.atlanta.ga.ibone.comcast.net [68.86.90.189]
  7    41 ms    42 ms    43 ms  so-6-1-0-0-ar01.greenspoint.tx.houston.comcast.net [68.86.94.134]
  8    43 ms    43 ms    41 ms  po-12-ur01.greenspoint.tx.houston.comcast.net [68.85.244.150]
  9     *        *       42 ms  cdns02.comcast.net [75.75.76.76]
 
Trace complete.
 
 


That traceroute test only shows the gateway that is used by that particular ICMP traceroute. The actual connections to DNS servers for real DNS queries is more complex and will usually point to more than just two DNS servers. A more comprehensive test can be easily done from the GRC DNS Nameserver Spoofability Test. That test does many, many real DNS queries to the DNS servers configured for your PC, and reports back a lot of information about those servers (including their real hostnames and IP addresses). In the test I just ran I got back replies form 28 different Comcast DNS servers located in Atlanta, Houston, and Naples.

I am attaching a zipped PDF file of the report from that test for those who might be interested in what kind of information is returned, but are afraid to click on the link I provided (of course, those folks will probably also be afraid to open the PDF file too).

downloadGRC_DNSNames···Test.zip 1167880 bytes


--
We can never have enough of nature.
We need to witness our own limits transgressed, and some life pasturing freely where we never wander.


NetFixer
Freedom is NOT Free
Premium
join:2004-06-24
The Boro
Reviews:
·Cingular Wireless
·Comcast Business..
·Vonage

4 edits
reply to JJJohnson

said by JJJohnson:

Just how bad _are_ Comcast's DNS servers? I switched to them briefly today. The two servers assigned through DHCP were 75.75.75.76 and 75.75.75.75. While using them I was getting at least 20% failed DNS lookups just doing typical web browsing. Jeezus, even www.google.com failed.

I switched back to using my own local caching DNS server (with OpenDNS servers as backups) and the problems disappeared. I find it almost hard to believe Comcast's servers are that godawful bad, even though I stopped using them 12 years ago for exactly the same reason.

Your experience has been very much different than my experience with Comcast's Anycast DNSSEC servers. I started using them in March, 2011 (when I started using a Comcast Business Class connection), and I have had absolutely no problems with them. Perhaps your problem was that you used 75.75.75.76 (not a valid Comcast DNS server) as the primary DNS server?


C:\>nslookup www.dslreports.com 75.75.75.76
DNS request timed out.
    timeout was 2 seconds.
*** Can't find server name for address 75.75.75.76: Timed out
Server:  UnKnown
Address:  75.75.75.76
 
DNS request timed out.
    timeout was 2 seconds.
DNS request timed out.
    timeout was 2 seconds.
*** Request to UnKnown timed-out
 
 


You should have used 75.75.75.75 as the primary, and 75.75.76.76 as the secondary.


C:\>nslookup www.dslreports.com 75.75.75.75
Server:  cdns01.comcast.net
Address:  75.75.75.75
 
Non-authoritative answer:
Name:    www.dslreports.com
Address:  209.123.109.175
 
C:\>nslookup www.dslreports.com 75.75.76.76
Server:  cdns02.comcast.net
Address:  75.75.76.76
 
Non-authoritative answer:
Name:    www.dslreports.com
Address:  209.123.109.175
 


FWIW, I don't use them "directly" either. I use them as the forwarding servers for my local Windows Server DNS server, and within my Comcast SMCD3G gateway router. I use the Windows server as primary, and the SMCD3G as secondary (but ultimately all external DNS queries go through the Comcast Anycast DNSSEC servers).


C:\>nslookup www.dslreports.com 192.168.9.2
Server:  dcs-srv.dcs-net
Address:  192.168.9.2
 
Non-authoritative answer:
Name:    www.dslreports.com
Address:  209.123.109.175
 
C:\>nslookup www.dslreports.com 192.168.10.254
Server:  gw2.dcs-net
Address:  192.168.10.254
 
Non-authoritative answer:
Name:    www.dslreports.com
Address:  209.123.109.175
 


If you would like to investigate the matter further, I would recommend trying the GRC DNS Benchmark Test and the GRC DNS Nameserver Spoofability Test. For my connection, the benchmark test usually puts the Comcast DNS servers in a tie position for second place with the Level3 4.2.2.x legacy Anycast DNS servers. My local servers (which ultimately forward external DNS queries to the Comcast servers) are of course always in first place (and OpenDNS is usually just an "also ran").
--
We can never have enough of nature.
We need to witness our own limits transgressed, and some life pasturing freely where we never wander.

andyross
Premium,MVM
join:2003-05-04
Schaumburg, IL

It should be mentioned that some .gov sites have occasional issues. It's not Comcast's fault, though. The keys for the .gov sites are regularly updated, but they don't broadcast the proper TTL or something like that, so Comcast tries to use expired ones.



NetFixer
Freedom is NOT Free
Premium
join:2004-06-24
The Boro
Reviews:
·Cingular Wireless
·Comcast Business..
·Vonage

said by andyross:

It should be mentioned that some .gov sites have occasional issues. It's not Comcast's fault, though. The keys for the .gov sites are regularly updated, but they don't broadcast the proper TTL or something like that, so Comcast tries to use expired ones.

Yep, sometimes being on the leading edge (in this case strict adherence to DNSSEC) sometimes means being on the bleeding edge. I know that I had to make changes in some of my DNS records in order for DNSSEC servers (and Comcast's servers in particular) to properly resolve them.
--
We can never have enough of nature.
We need to witness our own limits transgressed, and some life pasturing freely where we never wander.


jlivingood
Premium,VIP
join:2007-10-28
Philadelphia, PA
kudos:2

1 recommendation

reply to JJJohnson

said by JJJohnson:

Just how bad _are_ Comcast's DNS servers? I switched to them briefly today. The two servers assigned through DHCP were 75.75.75.76 and 75.75.75.75. While using them I was getting at least 20% failed DNS lookups just doing typical web browsing. Jeezus, even www.google.com failed.

You must have some other issue. You might imagine that if 20% of all our customer DNS queries failed you would have a thousand people posting here and articles in the press.

Next time you have this issue, run dig at the command line and post the results here, as well as a traceroute to the IP of the server.

So, dig @75.75.75.75 www.google.com
and then dig @2001:558:FEED::1 www.google.com
and then traceroute 75.75.75.75
and then traceroute6 2001:558:FEED::1

- Jason
--
JL
Comcast


jlivingood
Premium,VIP
join:2007-10-28
Philadelphia, PA
kudos:2
reply to andyross

said by andyross:

It should be mentioned that some .gov sites have occasional issues. It's not Comcast's fault, though. The keys for the .gov sites are regularly updated, but they don't broadcast the proper TTL or something like that, so Comcast tries to use expired ones.

Right on. See also section 5 of this doc -- »tools.ietf.org/html/draft-living···ection-5
--
JL
Comcast


NetFixer
Freedom is NOT Free
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join:2004-06-24
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reply to jlivingood

said by jlivingood:

said by JJJohnson:

Just how bad _are_ Comcast's DNS servers? I switched to them briefly today. The two servers assigned through DHCP were 75.75.75.76 and 75.75.75.75. While using them I was getting at least 20% failed DNS lookups just doing typical web browsing. Jeezus, even www.google.com failed.

You must have some other issue. You might imagine that if 20% of all our customer DNS queries failed you would have a thousand people posting here and articles in the press...

Of course, if he did actually use 75.75.75.76 as one of the DNS servers, that would readily explain the query failures.
--
We can never have enough of nature.
We need to witness our own limits transgressed, and some life pasturing freely where we never wander.


JJJohnson

join:2001-08-25
Fort Collins, CO

said by NetFixer:

Of course, if he did actually use 75.75.75.76 as one of the DNS servers, that would readily explain the query failures.

Naw, just copied the wrong IP. It was using DHCP, so whatever the IP addresses were handed out.


NetFixer
Freedom is NOT Free
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3 edits
reply to fxsapp

Well, I am going to have to update my previous statement that I have never had a problem with Comcast's Anycast DNSSEC servers.


C:\>nslookup test-ipv6.com 4.2.2.1
Server:  a.resolvers.level3.net
Address:  4.2.2.1
 
Non-authoritative answer:
Name:    test-ipv6.com
Address:  216.218.228.114
 
C:\>nslookup test-ipv6.com 68.94.156.1
Server:  dnsr1.sbcglobal.net
Address:  68.94.156.1
 
Non-authoritative answer:
Name:    test-ipv6.com
Address:  216.218.228.114
 
C:\>nslookup test-ipv6.com 75.75.75.75
Server:  cdns01.comcast.net
Address:  75.75.75.75
 
DNS request timed out.
    timeout was 2 seconds.
DNS request timed out.
    timeout was 2 seconds.
*** Request to cdns01.comcast.net timed-out
 
C:\>nslookup test-ipv6.com 68.87.68.162
Server:  nrcns.s3woodstock.ga.atlanta.comcast.net
Address:  68.87.68.162
 
DNS request timed out.
    timeout was 2 seconds.
DNS request timed out.
    timeout was 2 seconds.
*** Request to nrcns.s3woodstock.ga.atlanta.comcast.net timed-out
 
 


And the strange thing is that test-ipv6.com is one of the sites that Comcast directs you to use on their IPv6 Information Center site. That was how I discovered the problem. I had just made some network changes and I wanted to test IPv6 functionality.

EDIT: Well (at least for today), I have reverted to using the Level3 legacy 4.2.2.x servers for external DNS forwarding (they are marginally faster than Comcast's servers anyway).




Thank you, Level3 for allowing public access to your DNS servers.




Yeah, I know (7/10), but I'm stuck with using a tunnel until Comcast updates the firmware in their SMCD3G-CCR gateways and decides how they are going to handle native dual stack for their static IP business class customers.

EDIT: FWIW, the "mini-outage" didn't last very long . I only say the problem for ~ 2 hours...I kept a script file running doing nslookups until I noticed that they had started working again).


C:\>nslookup test-ipv6.com 75.75.75.75
Server:  cdns01.comcast.net
Address:  75.75.75.75
 
Non-authoritative answer:
Name:    test-ipv6.com
Address:  216.218.228.114
 
C:\>nslookup test-ipv6.com 75.75.76.76
Server:  cdns02.comcast.net
Address:  75.75.76.76
 
Non-authoritative answer:
Name:    test-ipv6.com
Address:  216.218.228.114
 
C:\>nslookup test-ipv6.com 68.87.68.162
Server:  nrcns.s3woodstock.ga.atlanta.comcast.net
Address:  68.87.68.162
 
Non-authoritative answer:
Name:    test-ipv6.com
Address:  216.218.228.114
 
 

--
We can never have enough of nature.
We need to witness our own limits transgressed, and some life pasturing freely where we never wander.


jlivingood
Premium,VIP
join:2007-10-28
Philadelphia, PA
kudos:2

I wonder if it was really DNS...

From NANOG:


Re: Bell Canada outage?
From: Darius Jahandarie
Date: Wed, 8 Aug 2012 14:35:41 -0400
On Wed, Aug 8, 2012 at 2:31 PM, Zachary McGibbon
wrote:
Anyone at Bell Canada / Sympatico can tell us what's going on? Our routing table is going nuts with Bell advertising a lot of routes they shouldn't be

Bell leaked a full table. To add to the fun, it seems that TATA took the full table and releaked it.

--
JL
Comcast


NetFixer
Freedom is NOT Free
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join:2004-06-24
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Reviews:
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1 edit

said by jlivingood:

I wonder if it was really DNS... ;-)

From NANOG:


Re: Bell Canada outage?
From: Darius Jahandarie
Date: Wed, 8 Aug 2012 14:35:41 -0400
On Wed, Aug 8, 2012 at 2:31 PM, Zachary McGibbon
wrote:
Anyone at Bell Canada / Sympatico can tell us what's going on? Our routing table is going nuts with Bell advertising a lot of routes they shouldn't be

Bell leaked a full table. To add to the fun, it seems that TATA took the full table and releaked it.

If it wasn't it a Comcast DNS problem ir was doing a really good job of imitating a Comcast DNS problem since both AT&T and Level3 DNS worked.

Here is a repost of the DNS query results from my previous post:

C:\>nslookup test-ipv6.com 4.2.2.1
Server:  a.resolvers.level3.net
Address:  4.2.2.1
 
Non-authoritative answer:
Name:    test-ipv6.com
Address:  216.218.228.114
 
C:\>nslookup test-ipv6.com 68.94.156.1
Server:  dnsr1.sbcglobal.net
Address:  68.94.156.1
 
Non-authoritative answer:
Name:    test-ipv6.com
Address:  216.218.228.114
 
C:\>nslookup test-ipv6.com 75.75.75.75
Server:  cdns01.comcast.net
Address:  75.75.75.75
 
DNS request timed out.
    timeout was 2 seconds.
DNS request timed out.
    timeout was 2 seconds.
*** Request to cdns01.comcast.net timed-out
 
C:\>nslookup test-ipv6.com 68.87.68.162
Server:  nrcns.s3woodstock.ga.atlanta.comcast.net
Address:  68.87.68.162
 
DNS request timed out.
    timeout was 2 seconds.
DNS request timed out.
    timeout was 2 seconds.
*** Request to nrcns.s3woodstock.ga.atlanta.comcast.net timed-out
 
 


I also had access to http://test-ipv6.com when using their DNS servers (as was also shown in my previous post), and I had no problems doing a ping or traceroute to 216.218.228.114 which doesn't even use DNS (perhaps I should have saved and posted those results as well); all of which indicated to me that the routing to the site from my Comcast connection was fine.

I will concede that it is certainly possible that something external to Comcast's DNS servers might have been responsible. However, the end result for someone using Comcast DNS servers was still a Comcast DNS problem (which did not effect AT&T or Level3 DNSSEC servers). Whatever the low level cause, it was fortunately quickly resolved and I reverted to using Comcast DNS servers for my external DNS query forwarding shortly after it started working again.

FWIW, the reason for my previous post was just for the sake of accuracy because I had earlier posted in this thread that I had never had a problem with the Comcast DNSSEC servers. I have certainly also seen similar brief site specific problems using DNS servers from AT&T, Level3, et al in the past (and if they had also been unable to resolve test-ipv6.com I would have not bothered to make my previous post).

--
We can never have enough of nature.
We need to witness our own limits transgressed, and some life pasturing freely where we never wander.

fxsapp

join:2005-10-03
Fargo, ND
reply to fxsapp

not to necro this thread but I wanted to update about the
situation. The outages have become more frequent, now they last 6 hours or more at a time. The gateway shows the connection as online (Linksys X2000) When we ping the gateway its fine, pinging any DNS server or website it is timed out. So what does that tell you? There has been techs to come out twice so far to look at the problem, 3rd tech scheduled to come tomorrow morning.



NetFixer
Freedom is NOT Free
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join:2004-06-24
The Boro
Reviews:
·Cingular Wireless
·Comcast Business..
·Vonage

1 edit

said by fxsapp:

not to necro this thread but I wanted to update about the
situation. The outages have become more frequent, now they last 6 hours or more at a time. The gateway shows the connection as online (Linksys X2000) When we ping the gateway its fine, pinging any DNS server or website it is timed out. So what does that tell you? There has been techs to come out twice so far to look at the problem, 3rd tech scheduled to come tomorrow morning.

It would really help to get your problem diagnosed if you provided some details. The vague symptoms you have described so far could be almost anything.

When your ping tests fail, are you pinging by IP address, or by hostname. Does the ping resolve the IP address of the host you are pinging? If you don't understand what I am asking, then how about showing us the actual ping tests you are doing. Since you seem to think that you are having a DNS problem, how about showing us the results of some DNS queries by using the nslookup command from a command window.

The following commands would tell us a lot about whether or not you have a DNS problem:

nslookup www.dslreports.com

nslookup www.dslreports.com 75.75.75.75

nslookup www.dslreports.com 4.2.2.1

nslookup www.dslreports.com8.8.8.8

The first nslookup will use your default DNS server (probably your gateway, but we don't know that at this since you did not supply the ipconfig information that was previously requested).

The second nslookup will use the Comcast Anycast DNS server.

The third nslookup will use a Level3 legacy DNS server.

The last nslookup will use a Google DNS server.

Here are my results for those commands to use as a reference:


C:\>nslookup www.dslreports.com
*** Can't find server name for address 192.168.9.1: Non-existent domain
*** Default servers are not available
Server:  UnKnown
Address:  192.168.9.1
 
Non-authoritative answer:
Name:    www.dslreports.com
Address:  209.123.109.175
 
C:\>nslookup www.dslreports.com 75.75.75.75
Server:  cdns01.comcast.net
Address:  75.75.75.75
 
Non-authoritative answer:
Name:    www.dslreports.com
Address:  209.123.109.175
 
C:\>nslookup www.dslreports.com 4.2.2.1
Server:  a.resolvers.level3.net
Address:  4.2.2.1
 
Non-authoritative answer:
Name:    www.dslreports.com
Address:  209.123.109.175
 
C:\>nslookup www.dslreports.com 8.8.8.8
Server:  google-public-dns-a.google.com
Address:  8.8.8.8
 
Non-authoritative answer:
Name:    www.dslreports.com
Address:  209.123.109.175
 
 


If none of the nslookups for www.dslreports.com work properly, try doing a ping 209.123.109.175. If that fails, then your problem is purely a connectivity problem, and has nothing to do with DNS.

Unless you provide us with some actual information that can be used for a diagnosis, nobody here is going to be able to do anything but reply with totally wild guesses. At this point, my guess is that you probably just have a problem with your gateway not being able to get IP connectivity (and hopefully that symptom will be present when the Comcast tech looks at your problems).

--
We can never have enough of nature.
We need to witness our own limits transgressed, and some life pasturing freely where we never wander.

fxsapp

join:2005-10-03
Fargo, ND

I'll try to provide more information for this issue, I apologize for not following the rules, I am providing this information for a friend, and it is difficult to relay the information from tracert and ping etc, through text messaging- but next time I will wait to post until I have all the proper info



NetFixer
Freedom is NOT Free
Premium
join:2004-06-24
The Boro
Reviews:
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1 edit

said by fxsapp:

I'll try to provide more information for this issue, I apologize for not following the rules, I am providing this information for a friend, and it is difficult to relay the information from tracert and ping etc, through text messaging- but next time I will wait to post until I have all the proper info

You didn't bread any rules; it is just that nobody is going to be able to properly diagnose your (and/or your friend's) problem without some real data to look at. Vague generic symptoms generate vague generic answers.

In case the problem is just a simple cable network connectivity problem, the modem's (or gateway's) connection stats and logs would be helpful as well as the results of the TCPIP connectivity tests I previously suggested.

Does your friend have a data plan for his/her cell phone? If so, this site's http://text.dslreports.com/ gateway might make access via a cell phone a bit easier so that your friend can personally take part in this thread (assuming that your friend's cable connection is so bad that using it is impossible).
--
We can never have enough of nature.
We need to witness our own limits transgressed, and some life pasturing freely where we never wander.

fxsapp

join:2005-10-03
Fargo, ND

turns out it it not a DNS issue, even though that is the error that we get when the connection goes down, for all of the tests 1 through 5 , nslookup and ping tests, all timed out- meaning that it is a connectivity issue, a tech has been out 3 separate times to look at the problem, changed modem, checked cabling no resolution. I'll try to get some logs from the modem and see what the errors are... I'm assuming the tech looked at that, but it seems like they cannot figure out what the problem is.