DNS servers with easy-to-remember IP addresses?

August 4, 2005 8:36 AM

Whenever I set up a new computer I have to scramble to figure out the IP addresses for two DNS servers. Are there any publicly accessible, stable DNS servers that have a particularly memorable IP address?

Failing that, is there a stable, publicly accessbile DNS server that you always use? Then at least I could look up this question when I need to find some DNS servers. :)

posted by pornucopia to computers & internet (19 comments total)

Does your ISP have DNS servers that you use, or do you just mean in general, at anyone's house, etc. My old ISP has publicly accessible DNS and their numbers seem to be listed a few places online.
posted by jessamyn at 8:49 AM on August 4, 2005

one thing that can make it easier is simply pointing to the gateway ip address -- many home and business routers support the function of mirroring dns. e.g. a home router which gets everything dynamically from the isp can simply reflect the dns servers that it has gotten. of course sometimes you still have to choose dns servers for said router; if you happen to have a web hosting service, why not point to their dns servers?
posted by dorian at 8:51 AM on August 4, 2005

I second dorian. All of my home boxes have their DNS set to 192.168.0.1, which is the router.
posted by xmutex at 8:54 AM on August 4, 2005

Well how about that.
posted by pornucopia at 8:58 AM on August 4, 2005

Pretty good answer there, dorian. I'm doing that now. But if anyone knows a memorable DNS IP, please list it just in case, so I'll have it in mind if I need it some time.
posted by pornucopia at 8:59 AM on August 4, 2005

There are about a million DNS servers on the net that you could use -- but the point is not that you should just use any of them, but that you really should use the DNS servers that are provided by the ISP of the network on which you're setting up the computer.

In normal, everyday internet use, a computer makes a ton of DNS requests; for example, every time you load a web page, chances are good that you have to make a handful of resolution requests (especially if parts of the page are hosted on different servers scattered around the net). If you use DNS servers that are close, network-wise, to your machine, then that DNS request-and-reply process is that much faster, and there's less congestion being broadcast across the 'net for simple name resolution. Every ISP (dial-up, broadband, etc.) has DNS servers available for use, because the ISP wouldn't be able to host a network without 'em (they need to not only provide resolution for their own domain names, but they need to provide reverse-resolution for the entire IP address block that's been granted to them). Many ISPs have boatloads of DNS servers -- my T1 provider has DNS servers in Boston for its Boston customers, DNS servers in NYC for its NYC customers, etc., all in the name of keeping resolution requests as local to the customers as possible.

So that's the longwinded way of saying that there are certainly DNS server IP addresses that you could find, memorize, and use on machines that you're setting up, but you'd be doing yourself a disservice unless those DNS servers were on network A and you're only ever setting machines up on that same network A.
posted by delfuego at 9:01 AM on August 4, 2005

cheers, pornucopia. you could always use the tier 2 servers from opendns / opennic, I s'pose.
posted by dorian at 9:12 AM on August 4, 2005

I don't think people understand the question. Perhaps it is just that computer geeks don't like the question, I'm not sure...

UofT's subnet is 128.100.x.x, so with great wisdom UofT gave their primary DNS the IP 128.100.100.128, which is easily remembered. The question is, is there a similar publicly accessible DNS?

I don't know of one, I don't suppose UofT's will work for you, but it is worth a try I guess.
posted by Chuckles at 9:14 AM on August 4, 2005

I learned to use 198.6.1.1 years ago. It's been alive and solid since 1996. It at least gets me far enough to use other tools to find closer/faster DNS servers.
posted by joelr at 9:15 AM on August 4, 2005

Yep, when in a similar situation I use:

4.2.2.2
4.2.2.3
4.2.2.4
4.2.2.5
4.2.2.6

As soon as I can figure out what the ISP's dns servers are set to I remove the 4.x.x.x entries, there's no need to trample on their bandwidth when it's not necessary.
posted by ordu at 9:21 AM on August 4, 2005

Yeah, the 4.2.2.x ones are Verizon's. Very memorable, I use them often.
posted by kindall at 11:08 AM on August 4, 2005

The other big reason to use local DNS servers, rather than random ones out there on the 'net, is that if a link between you and the random DNS servers goes down BUT your link to the rest of the internet is alive and well, it's functionally like you have no connectivity whatsoever.

That is to say, if your internet connection is fine, and your ISP's connection to the internet at large is fine, but the link between the internet at large and your chosen DNS servers is down, then your ability to use any connections that rely on DNS is also horked, despite you having a perfectly good connection to most of the internet.

(I know most people here understand this, but it seems that some people don't, and it's worth clarifying.)
posted by delfuego at 11:52 AM on August 4, 2005

Be sure you know who runs the DNS server you use, and be able to trust them and their security completely. Whomever controls the DNS server can easily make 'www.paypal.com' point wherever they want.
posted by bemis at 12:51 PM on August 4, 2005

The other big reason to use local DNS servers, rather than random ones out there on the 'net, is that if a link between you and the random DNS servers goes down BUT your link to the rest of the internet is alive and well, it's functionally like you have no connectivity whatsoever.

Sure, but the same is true if your ISP's DNS servers go down, which is why using a couple different ISP's DNS servers as secondaries is a good idea.
posted by kindall at 1:37 PM on August 4, 2005

Sure, but the same is true if your ISP's DNS servers go down, which is why using a couple different ISP's DNS servers as secondaries is a good idea.

Well, that's why you use primary and secondary DNS -- it's unlikely that BOTH of your ISP's DNS servers would go down unexpectedly. And a good ISP won't bring down all their DNS servers at the same time for maintenance or upgrades, for the same reason.

Really, if you configure your machine to use primary and secondary servers from your own ISP and you're getting bad results, then there's less a reason to use some other random ISP's DNS servers than to question your choice of ISP -- DNS servers are easy, and there's no reason your ISP shouldn't be getting it right.
posted by delfuego at 2:01 PM on August 4, 2005

The issue at hand, to clarify a tad, is "recursive" or "resolver" servers, the ones you point a PC at to (dih) resolve adresses. They're called that to distinguish them from "zone" servers, which answer for domains.

I concur: I too use the Verizon/GTE/BBN servers at 4.2.2.1 through 4.2.2.6; those are "anycast" servers, where the physical server to which the address maps depends on the network topology of where you are when your packets enter the 4/8 network.

And yes, it *is* good to use a resolver server as close to you as possible; you cut quite a fair bit of delay out of many steps by doing that. If your workstation (or server) caches lookups, it's not quite as important; if, like most Linuxen, it *runs* a local resolver server, the issue goes away entirely.
posted by baylink at 2:49 PM on August 4, 2005

Back years ago when I first started doing log analysis of my website's traffic, I got really annoyed at how long the reverse DNS lookups were taking with my ISPs nameservers. So I downloaded the bind9 binaries for windows and ran my own caching recursive resolver. It was much, much faster for doing bulk rDNS lookups.

I don't know if Comcast (they were AT&T Broadband at that point) had shitty overloaded servers or what. I do know that recently Comcast had problems with their nameservers going down, and this affected their entire customer base. But not me.

I only mention this because it seems like people don't realize that they don't necessarily have to be reliant on anyone else for a DNS server, you can run one yourself on your workstation.
posted by Rhomboid at 7:30 PM on August 4, 2005

Rhomb--

So I was just talking with someone about the Comcast nameserver outage (Paul Mockapetris, actually...yes, that one). Turns out their Bind9 systems were overloading right around tax day. DNS seems simple but you have alot of rules that need to be followed, and of course you're demanding a remote server do lookups on your behalf with some complexity. Comcast ended up buying systems from Nominum over that outage, which lasted a couple weeks and did interfere with the payment of taxes.

FWIW -- running local DNS, or 4.2.2.1, has always worked well for me.
posted by effugas at 4:11 AM on August 5, 2005

it's unlikely that BOTH of your ISP's DNS servers would go down unexpectedly

Perhaps it's not very likely, but it's certainly happened to me more than once. And no matter how unlikely it is, it's even less likely that two different ISP's DNS servers would go down unexpectedly at the same time.
posted by kindall at 6:15 PM on August 17, 2005