alternatives to OpenDNS?

slackhack · 04-26-2008, 03:28 PM

OpenDNS used to be good, but it looks like they're crapping out. I was upgrading some packages, and my dload speed was <80-100K/s, at times going down to single digits.

traceroute seems to suggest OpenDNS or whatever is this "cogentco" is the problem:

Code:

jeff@moe:~ $ traceroute www.google.com
traceroute to www.google.com (208.69.32.230), 30 hops max, 40 byte packets
 1  lou (192.168.0.1)  0.442 ms  0.578 ms  0.662 ms
 2  10.193.32.1 (10.193.32.1)  6.180 ms  10.695 ms  11.208 ms
 3  gig1-0-2.albynysch-rtr01.nyroc.rr.com (24.29.39.129)  11.282 ms  11.875 ms  11.963 ms
 4  gig5-1-0.albynywav-rtr02.nyroc.rr.com (24.29.37.37)  12.071 ms  12.134 ms  12.198 ms
 5  * * *
 6  ae-3-0.cr0.chi10.tbone.rr.com (66.109.6.72)  40.313 ms  40.224 ms  40.189 ms
 7  ae-0-0.pr0.chi10.tbone.rr.com (66.109.6.153)  39.429 ms  31.672 ms  31.880 ms
 8  te9-2.ccr02.ord03.atlas.cogentco.com (154.54.11.145)  32.576 ms  32.992 ms  33.110 ms
 9  vl3491.ccr02.ord01.atlas.cogentco.com (154.54.6.209)  33.557 ms vl3498.ccr02.ord01.atlas.cogentco.com (154.54.5.1)  34.237 ms  33.641 ms
10  te7-2.ccr02.bos01.atlas.cogentco.com (154.54.6.181)  40.363 ms te2-1.ccr02.bos01.atlas.cogentco.com (154.54.7.170)  40.811 ms  41.313 ms
11  te2-3.ccr02.dca01.atlas.cogentco.com (154.54.6.138)  45.365 ms  46.386 ms  45.835 ms
12  te4-1.mpd01.dca02.atlas.cogentco.com (154.54.2.182)  41.877 ms te7-3.mpd01.dca02.atlas.cogentco.com (154.54.6.26)  41.689 ms te4-1.mpd01.dca02.atlas.cogentco.com (154.54.2.182)  41.685 ms
13  vl3496.mpd01.iad01.atlas.cogentco.com (154.54.5.46)  45.312 ms vl3497.mpd01.iad01.atlas.cogentco.com (154.54.5.66)  44.288 ms vl3494.mpd01.iad01.atlas.cogentco.com (154.54.5.42)  43.766 ms
14  opendns.demarc.cogentco.com (38.104.56.50)  44.658 ms  42.185 ms  41.437 ms
15  * * *
16  * * *
17  * * *
18  * * *
19  * * *
20  * * *
21  * * *
22  * * *
23  * * *
24  * * *
25  * * *
26  * * *
27  * * *
28  * * *
29  * * *
30  * * *

what can I use instead? I don't even know anymore what my ISP uses, and when I called them they wouldn't tell me b/c when they said what OS is it, XP or Vista, I said no, it's linux. Then they got weird and said, that should "come up automatically,"sorry, we don't support linux so I can't really tell you want to do.

I said, "I just want to know the IP of the DNS servers I should use," and they wouldn't tell me because it's linux! lol, unbelievable.

NetRAVEN5000 · 04-26-2008, 05:01 PM

Cogent Communications sells Internet access.

From the looks of it, your ISP doesn't know what they use because they're leasing a line from Cogent, who is using OpenDNS. I'm not 100% on that, but that's what it looks like anyhow.

According to OpenDNS' site, their IP addresses are 208.67.222.222 and 208.67.220.220 - so the "opendns.demarc.cogentco.com (38.104.56.50)" you see isn't an OpenDNS server. I'd guess that this is Cogent's own DNS but piggy-backs off of OpenDNS. You might try forcing your network to try OpenDNS' own servers and see if that works.

Do you have a home router? From the looks of it you do. . . if you do, usually in one of the setup pages it'll tell you the IP addresses of the DNS servers it's using (mine does, anyway - and my previous ones have too).

Note that I've never used any DNS other than the one assigned by my ISP - but I imagine it's no tougher than telling a static-IP computer to use the same DNS as your home router, and you just tell it what IP addresses to use for the DNS (sorry, I don't remember how to do it in Slack. . .)

Looking at OpenDNS' site, though. . . maybe I should have my router try to use their servers. . .

bulliver · 04-26-2008, 05:23 PM

Quote:

I don't even know anymore what my ISP uses, and when I called them they wouldn't tell me b/c when they said what OS is it, XP or Vista, I said no, it's linux. Then they got weird and said, that should "come up automatically,"sorry, we don't support linux so I can't really tell you want to do. I said, "I just want to know the IP of the DNS servers I should use," and they wouldn't tell me because it's linux! lol, unbelievable.

Unbelievable yes, but also true.

I have had Telus cust service hang up on me saying "We don't support linux" when I phoned to ask the name of their pop3 server. In response I ditched them (this was for mu Mom actually) and went with a different (less clueless) ISP. These guys just read from scripts, and if you answer something that is not in their script they get very afraid and start spewing "We don't support X"... nonsense.

My suggestion, phone again, ask for the IPs of thier DNS servers (should be 2). Just tell them you use XP and say "uh-huh, uh-huh" over and over while they read the "Now click on 'my computer...' until they tell you. Then add both IPs to /etc/resolv.conf.

slackhack · 04-26-2008, 08:18 PM

Quote:

Originally Posted by NetRAVEN5000

Cogent Communications sells Internet access.

From the looks of it, your ISP doesn't know what they use because they're leasing a line from Cogent, who is using OpenDNS. I'm not 100% on that, but that's what it looks like anyhow.

According to OpenDNS' site, their IP addresses are 208.67.222.222 and 208.67.220.220 - so the "opendns.demarc.cogentco.com (38.104.56.50)" you see isn't an OpenDNS server. I'd guess that this is Cogent's own DNS but piggy-backs off of OpenDNS. You might try forcing your network to try OpenDNS' own servers and see if that works.

Do you have a home router? From the looks of it you do. . . if you do, usually in one of the setup pages it'll tell you the IP addresses of the DNS servers it's using (mine does, anyway - and my previous ones have too).

Note that I've never used any DNS other than the one assigned by my ISP - but I imagine it's no tougher than telling a static-IP computer to use the same DNS as your home router, and you just tell it what IP addresses to use for the DNS (sorry, I don't remember how to do it in Slack. . .)

Looking at OpenDNS' site, though. . . maybe I should have my router try to use their servers. . .

I see. I actually use OpenDNS in my router, and map all my client PCs there. When I saw opendns in the name, at first I just assumed it had something to do with that, but now I see what you mean about it being "piggybacked" by cogent. I guess something there is blocking my IP for some reason. ?

slackhack · 04-26-2008, 08:25 PM

Quote:

Originally Posted by bulliver

Unbelievable yes, but also true.

I have had Telus cust service hang up on me saying "We don't support linux" when I phoned to ask the name of their pop3 server. In response I ditched them (this was for mu Mom actually) and went with a different (less clueless) ISP. These guys just read from scripts, and if you answer something that is not in their script they get very afraid and start spewing "We don't support X"... nonsense.

My suggestion, phone again, ask for the IPs of thier DNS servers (should be 2). Just tell them you use XP and say "uh-huh, uh-huh" over and over while they read the "Now click on 'my computer...' until they tell you. Then add both IPs to /etc/resolv.conf.

I did call them again, and this time got the "national" help desk (as opposed to the local, I guess). the guy was actually pretty nice and we had a discussion about backbones, etc. Anyway, he had me do a traceroute and when some * came up this time in their servers, he was able to send it to the network engineers. I just said "windows XP" and pretended I was on windows, and everything was fine.

Anyway, no solution from them, but they're actually going to have someone come here next week to see if they can find the problem. Not sure what they expect to find here that they can't find on their own -- they've already tested the modem and said that's receiving fine. I wonder what's going to happen when they find a 6 computer LAN on linux all attached to a linux router.

I guess I'll have to boot up my laptop into XP to accommodate them, so they won't get too freaked out and run terrified and screaming from the house.

IBall · 04-26-2008, 10:32 PM

Are you sure it is a DNS problem?

By the looks of that Traceroute, I would suggest maybe congestion within Cogentco's network.

When you do a traceroute, a DNS lookup is performed first to get the IP address of the host you are tracing to. After that, DNS should not play a part, as internet routing is done using IP addresses not DNS addresses.

Having said all that, the latencies look OK to me, but then - I live in Australia so we always get high latency

--Ian

NetRAVEN5000 · 04-27-2008, 10:23 AM

Make sure your laptop is plugged in rather than wifi, so they won't blame your wifi router. Usually when I call, they have me try plugging my computer directly into the modem - you might try that too before they come, just so they can't tell you something's wrong with the router. They've tried to tell me that before - that my router's configured wrong (when the same config has been working fine for at least a few months, or even years).

What IBall said might be true too - maybe it's just too much congestion. Nothing you can do in that case, except call and let them know how slow it is, and hopefully they'll fix it so that you don't feel the effects so much. I remember when we first got cable, you could really tell when everyone was online - I got home from school around 4:00, and when people got home around 5:30 I could feel it slowing down since they didn't do a good job of balancing the load.

slackhack · 04-27-2008, 11:44 AM

I just came across this:
http://forums.opendns.com/comments.p...cussionID=1170

so apparently there are problems with this "cogentco." think I should email them with the traceroute, or wouldn't they care?

NetRAVEN5000 · 04-27-2008, 11:53 AM

Quote:

Originally Posted by slackhack

so apparently there are problems with this "cogentco." think I should email them with the traceroute, or wouldn't they care?

I would e-mail them the traceroute, and send them that link too so they see it's not just you having trouble. They might not do anything, but I think they might if they see that someone else is having the same (or similar) trouble.

IBall · 04-27-2008, 08:24 PM

Quote:

Originally Posted by slackhack

apparently there are problems with this "cogentco." think I should email them with the traceroute, or wouldn't they care?

Cogentco will be a backhaul provider for other ISPs to use.

Your ISP will buy bandwidth of Cogentco directly, or they will go through a third party.

In my experience (I work for an ISP), only the ISP will be able to lodge a fault with the upstream provider. They will simply ignore a traceroute if you send it.

I suggest that your best solution would be to persevere with your ISP and get them to lodge a fault with Cogentco. I know the general helpdesk staff are probably reading a script, but there should be some senior helpdesk or ISP engineers or Network engineers who will understand your problem.

--Ian