Comments on: Speed Up Web Browsing by Caching DNS to Your Hard Drive in Ubuntu.

By: UbuntuLinuxHelp

UbuntuLinuxHelp — Sat, 21 Mar 2009 12:48:10 +0000

@alex – Thanks for catching and correcting that for us! :) Between the two of us, I’m glad that at least you know what you’re doing. Hee hee hee… I’ve corrected that command in the post, thanks again and have a good one! – Cheers!

By: alex

alex — Sat, 21 Mar 2009 05:08:52 +0000

instead of digg ubuntu.com its dig ubuntu.com like in your terminal… took me a minute to work that out :P

By: UbuntuLinuxHelp

UbuntuLinuxHelp — Wed, 03 Dec 2008 12:57:40 +0000

@Ray – Does your NIC have an IP address? Maybe it does not, is it local or public?

By: UbuntuLinuxHelp

UbuntuLinuxHelp — Wed, 03 Dec 2008 12:53:38 +0000

@pistole – That’s sweet. Thanks. (It’s also about time I had another look at Fedora. – I dropped out at Fedora Core 2).
The binding of ISP servers tip was also pretty good – Cheers!
Thanks! :)

By: Ray

Ray — Wed, 03 Dec 2008 06:15:48 +0000

After install pdnsd resolvconf

check with the /etc/resolv.conf

i see only 127.0.0.1

when i try to ping outside like yahoo.com

it show unknown host..

please advise

By: pistole

pistole — Mon, 01 Dec 2008 22:28:30 +0000

@UbuntuLinuxHelp

On a Fedora box, simply do this:

# yum install caching-nameserver

It will automatically select other packages to satisfy dependancies.
When setup, make sure you don’t allow DNS queries from the internet to your box; when done properly your ISP won’t “see” that you have you’re own nameserver.

If you’d like bind to use your ISP’s nameservers instead of doing recursive queries, edit the named.conf (/etc/named.conf or /var/named/chroot/etc/named.conf), and put in your ISP’s nameservers as “forwarder”:

forward ( only );
forwarders { ip-address ; ip-address ; }

By: Hobbsee

Hobbsee — Thu, 20 Nov 2008 06:59:10 +0000

I just tried this on Intrepid Ibex. Unfortunately, it doesn’t quite work – Network Manager is used by default now, and controls resolv.conf. So, you can’t use resolvconf, as it’ll break your entire DNS (leaving it blank).

However, what you *do* need to do is follow part of the first article:

—————-
“Now edit /etc/dhcp3/dhclient.conf and make sure the section below exactly like this, especially the line that says “prepend domain-name-servers 127.0.0.1;”

#supersede domain-name “fugue.com home.vix.com”;
prepend domain-name-servers 127.0.0.1;
request subnet-mask, broadcast-address, time-offset, routers,
domain-name, domain-name-servers, host-name,
netbios-name-servers, netbios-scope;”
———————

and then kill network manager, and restart it. Then it works a charm!

By: UbuntuLinuxHelp

UbuntuLinuxHelp — Mon, 03 Nov 2008 16:15:38 +0000

@pistole – Do you have the details on how to do that properly. I tried it a couple years back and got an email from my ISP saying that I have to stop running a server on my local network or they would eventually cut of services. I thought the DNS was in caching mode only – Obviously I was wrong.

If you don’t have the install details, do you have a link?
Thanks again and have a good one! :)

By: pistole

pistole — Sun, 02 Nov 2008 16:57:45 +0000

Well I guess (no, I’m sure) that I’m spoiled with my ISP that has good DNS servers.
On the other hand, I run my own (caching only) nameserver on my Fedora box @home so I never experience any delays from DNS lookups :)

By: UbuntuLinuxHelp

UbuntuLinuxHelp — Fri, 31 Oct 2008 14:27:37 +0000

@pistole – Thanks for the input. I think in some aspects it’s a case of ISP DNS reliability/performance (or of non-ISP based DNS servers for those who use them) and even network performance. I found in my personal experience that my surfing speed had considerably improved as I was making less and less DNS requests. As we surf through web pages, our browsers make a separate download request for every single element of that page (scripts, style sheets, images, etc.) and each of those requires a DNS lookup. Pages quite literally can include many, many numbers of elements. as such this is one thing that can impact surfing speeds. Now if I’m browsing through several sites and related pages, a local DNS cache has reduced the number of DNS requests, which in turn mitigated the browsing performance loss. As such, web browsing speed improved. :)

Also, I think you are quite right in that caching DNS is a must for servers as that has an even greater performance improvement. :) ;)

By: pistole

pistole — Thu, 30 Oct 2008 22:15:34 +0000

I’m not sure why anyone (who isn’t a server admin) should cache DNS lookups locally?

For instance, when I query the DNS of my ISP for a record, it will (of course) dig up the address, walking down the “DNS tree” (or should you climb up a tree?).

A second address for the same record will then also be cached at my ISP’s DNS servers!

So, what’s the need then for a local cache when you can use the ISP’s cache?

Other discussion: do you really think that 70 or 150 millisecond of lookup delay will impact your websurfing experience dramatically?

cheers!

1st query:
;; Query time: 130 msec

2nd query:
;; Query time: 2 msec

By: UbuntuLinuxHelp

UbuntuLinuxHelp — Tue, 15 Apr 2008 14:15:35 +0000

@Vadim P. – I did this on 7.10 as well and it caused no problems. I’ve not tried on 8.04, yet. I’m waiting for the stable release to come out (I think it’s about 9 or 10 days before release).

By: Vadim P.

Vadim P. — Tue, 15 Apr 2008 14:02:30 +0000

Does this still apply on 7.10 and 8.04?

By: UbuntuLinuxHelp

UbuntuLinuxHelp — Thu, 03 Apr 2008 21:39:23 +0000

@tallman – That’s fast! :)

By: tallman

tallman — Thu, 03 Apr 2008 21:22:16 +0000

;; Query time: 0 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Fri Apr 4 00:20:33 2008
;; MSG SIZE rcvd: 156

I am using bind for this.