Caching Nameserver?

lordy · 08-02-2006, 02:55

Does anyone find it better(faster) to use a caching nameserver rather than
either
ntl name servers
or
their Router (pointing to NTL nameservers)?

Lordy

**Paul** · 08-02-2006, 04:22

What exactly do you mean by a caching nameserver ?

Matthew · 08-02-2006, 07:38

I think Lordy means DNS servers but I could be wrong.

lordy · 08-02-2006, 11:16

Yup. A cahcing Nameserver is a local DNS Server running on your own box. So every DNS request is resolved on your own machine.
This improved things in the old 'dial-up' days. but I'm guessing even with cable/asdl every little bit helps.

I was just wondering if the Linksys routers also implement their own DNS caching (unlikely) or simply pass the request through to the DNS servers provided by the ISP. Now I think about it, its very likely the latter.

The good thing about a local nameserver is that it syncs with the root servers directly. No middleman. So you should get dns updates a bit quicker?

Gareth · 08-02-2006, 11:35

A local DNS server...? Nope, I've never bothered with this for home use. It has always seemed overkill to me. Even when on dial-up, the advantage of using your ISP's DNS (or any other DNS) seems outweighed by the work involved in configuring and maintaining your DNS.

I remember looking into this with the Sys Admin for the 1st company I worked for... but got made redundant before any decision was made (maybe that's why I got made redundant

).

lordy · 08-02-2006, 13:06

Quote:

Originally Posted by Gareth

A local DNS server...? Nope, I've never bothered with this for home use. It has always seemed overkill to me. Even when on dial-up, the advantage of using your ISP's DNS (or any other DNS) seems outweighed by the work involved in configuring and maintaining your DNS.

It just runs locally on each box. On my mandrake box its just the command

"urpmi caching-nameserver"

And its all installed and configured.

It's not quite the same as having a local DNS server for your home network. More like a local DNS server on each machine independantly. But when you've only got one machine its a moot point

**Paul** · 08-02-2006, 14:44

Completely pointless I would have thought, certainly in modern windows (2000/xp) as the dns resolver caches the results anyway.

---------- Post added at 14:44 ---------- Previous post was at 14:42 ----------

Quote:

Originally Posted by lordy

The good thing about a local nameserver is that it syncs with the root servers directly. No middleman. So you should get dns updates a bit quicker?

Would you like to explain that - how would a local dns server not behave exactly like any other dns server.

lordy · 08-02-2006, 17:04

Quote:

Originally Posted by Paul M

Completely pointless I would have thought, certainly in modern windows (2000/xp) as the dns resolver caches the results anyway.

Ie. Windows XP/2000 have DNS Cache by default. I didnt realise that.
I also I dont run windows, so not completely pointless for me. Googleing 'Windows DNS Cache" reveals its not without its own problems though.

Quote:

Originally Posted by lordy

The good thing about a local nameserver is that it syncs with the root servers directly. No middleman. So you should get dns updates a bit quicker?

Quote:

Originally Posted by Paul M

Would you like to explain that - how would a local dns server not behave exactly like any other dns server.

I guess, I thought it would depend on how often the external DNS server is configured to update, as some seem to take longer to sync with Root servers than others. That's all I was getting at.

bilal · 08-02-2006, 18:01

well at the moment my router is set up as my dns server so if u want to get a router then maybe that will help...

**Paul** · 08-02-2006, 20:45

Quote:

Originally Posted by lordy

I guess, I thought it would depend on how often the external DNS server is configured to update, as some seem to take longer to sync with Root servers than others. That's all I was getting at.

DNS servers are not configured to update - every dns record has an expiry time (TTL) associated with it, and the dns server will update the record the first time it is asked for it after the expiry period has passed. Typical TTL's can be anything from 2 hours to 2 days.

lordy · 08-02-2006, 21:20

Quote:

Originally Posted by Paul M

DNS servers are not configured to update - every dns record has an expiry time (TTL) associated with it, and the dns server will update the record the first time it is asked for it after the expiry period has passed. Typical TTL's can be anything from 2 hours to 2 days.

OK. Fair enough. My main point, from a Linux perspective, was that as its so trivial to set up a caching nameserver, (indeed XP has DNS caching by default) is it worth doing the same thing on Linux,
given that

1)Im not overly impressed with NTLs proxies and infrastructure at the moment - so I was wondering if the DNS is up to scratch. (I've seen NTL's DNS mentioned a lot in these forums though I havent poured over it in detail)

2) some DNS servers seem to take ages to update regardless of TTL. Which was what I was getting at regarding my earlier statement that it may be better to have your own local one, properly configured..

http://ask.slashdot.org/article.pl?sid=05/04/18/198259

Quote:

Originally Posted by bilil

well at the moment my router is set up as my dns server so if u want to get a router then maybe that will help...

Yes I do have a router with DNS set up, but earlier in the thread I mentioned I suspect this may simply be passthrough rather than caching.