Improving your resolv.conf file

#1

Post by datums » Sat, May 01, 2010, 7:52 PM UTC

Improving your resolv.conf file
edwin.io

Re: Improving your resolv.conf file

#2

Post by viraptor » Sat, May 01, 2010, 8:40 PM UTC

There's no "why". There's no justification for the word "improving" either. No interesting content really.

Even the man page is better: http://linux.die.net/man/5/resolv.conf

"Optimised" resolv.conf has one line - 127.0.0.1 and the host runs a local cache (dnsmasq / bind / djbdns / ...)

Re: Improving your resolv.conf file

#3

Post by avar » Sat, May 01, 2010, 9:42 PM UTC

viraptor wrote: post #2

There's no "why". There's no justification for the word "improving" either. No interesting content really. Even the man page is better: http://linux.die.net/man/5/resolv.conf "Optimised" resolv.conf has one line - 127.0.0.1 and the host runs a local cache (dnsmasq / bind / djbdns / ...)

Actually using Google's nameservers are really fast compared to a default Bind/PowerDNS setup.

I have a PowerDNS setup on localhost that was a lot slower than Google's servers. That's because by default it recurses to the root servers.

I found that the fastest setup in my case was to use PowerDNS and have it recurse via bt.com servers (this is in London). BT is a big commercial provider so what I need is often hot in their cache, the same goes for Google.

Re: Improving your resolv.conf file

#4

Post by viraptor » Sat, May 01, 2010, 9:59 PM UTC

avar wrote: post #3

viraptor wrote: post #2

There's no "why". There's no justification for the word "improving" either. No interesting content really. Even the man page is better: http://linux.die.net/man/5/resolv.conf "Optimised" resolv.conf has one line - 127.0.0.1 and the host runs a local cache (dnsmasq / bind / djbdns / ...)

Actually using Google's nameservers are really fast compared to a default Bind/PowerDNS setup. I have a PowerDNS setup on localhost that was a lot slower than Google's servers. That's because by default it recurses to the root servers. I found that the fastest setup in my case was to use PowerDNS and have it recurse via bt.com servers (this is in London). BT is a big commercial provider so what I need is often hot in…

Try a server which is only caching instead -- not the normal standalone resolution. For example dnsmasq caches entries locally, but you can select the "upstream" servers yourself, so that you do either no internet queries or only one. In that case asking dnsmasq, which is configured to use 3 google dns servers, is never slower than configuring them in resolv.conf. You never hit the root servers yourself.

Re: Improving your resolv.conf file

#5

Post by skorgu » Sat, May 01, 2010, 10:45 PM UTC

> nameserver 4.4.4.4

Please don't do this unless you're a GTE/Verizon customer. Use your ISP's or run a resolver yourself.

Re: Improving your resolv.conf file

#6

Post by steveklabnik » Sat, May 01, 2010, 11:07 PM UTC

skorgu wrote: post #5

> nameserver 4.4.4.4 Please don't do this unless you're a GTE/Verizon customer. Use your ISP's or run a resolver yourself.

Isn't that a Google nameserver?

Oh wait, that's 8.8.4.4. Maybe that's what he meant.

And now I checked the article. That's what it says now.

Re: Improving your resolv.conf file

#7

Post by qbi » Sun, May 02, 2010, 12:24 AM UTC

I wrote an additional entry on how to find to optimal nameserver: http://www.kubieziel.de/blog/archives/1343-Improving-your-re...

Re: Improving your resolv.conf file

#8

Post by mhansen » Sun, May 02, 2010, 1:34 AM UTC

Try out namebench. It hunts down the fastest DNS servers available for your computer to use. namebench runs a fair and thorough benchmark using your web browser history, tcpdump output, or standardized datasets in order to provide an individualized recommendation.

http://code.google.com/p/namebench/

Re: Improving your resolv.conf file

#9

Post by sandGorgon » Sun, May 02, 2010, 4:52 AM UTC

hmmm.. what distro is this ?

Because AFAIK, ubuntu distros (and maybe redhat/fedora even) suffer from multisecond delays due to ipv6 lookups - https://bugs.launchpad.net/ubuntu/lucid/+source/eglibc/+bug/...

I thought this article had some solution to that (other than disabling ipv6, right now) - but dont think so

Re: Improving your resolv.conf file

#10

Post by Auzy83 » Sun, May 02, 2010, 6:29 AM UTC

avar wrote: post #3

viraptor wrote: post #2

There's no "why". There's no justification for the word "improving" either. No interesting content really. Even the man page is better: http://linux.die.net/man/5/resolv.conf "Optimised" resolv.conf has one line - 127.0.0.1 and the host runs a local cache (dnsmasq / bind / djbdns / ...)

Actually using Google's nameservers are really fast compared to a default Bind/PowerDNS setup. I have a PowerDNS setup on localhost that was a lot slower than Google's servers. That's because by default it recurses to the root servers. I found that the fastest setup in my case was to use PowerDNS and have it recurse via bt.com servers (this is in London). BT is a big commercial provider so what I need is often hot in…

Actually, that may be true, but recently, with my website http://code.getnightingale.org, I had SERIOUS troubles accessing my DNS once (the TTL was set very low, and even after fixing it, it didn't work in Google DNS). Turns out, it was because of Google's nameservers. Moment I changed, it was fine (must be a bug in their setup).

Anyway, this isn't much of an improvement honestly..