How to change the default DNS Servers in a Thomson Router

[#1]

First a little background. Unlike many routers many Thomson models have emasculated firmware which allows only very limited controls from the web interface and many commands are only available using Command Line Instructions (CLI). In order to change the DNS servers it is necessary to utilise this feature via the telnet command.

These instructions are known to work on the Speedtouch ST546 and ST585 v6, the Gateway TG585 v7 and v8 and the TG582n using the appropriate usernames and passwords.

Operating systems known to be supported in this guide are Windows XP, Vista and Windows 7

For Vista and Windows 7 it will be necessary to enable the telnet command as it is disabled by default.

To do this go to “Control Panel”, “Programs and Features” then “Turn Windows Features on or off”. You should then scroll down and tick “Telnet Client”

It will now be necessary to open a DOS window.

In XP and Vista it is relatively easy. Click on the start menu button and select “Run” then type CMD and then press the Enter key. This will open a DOS window.

In Windows 7 it is more difficult as the Run command is hidden by default. The easy way out of this is to right click on the desktop, select “New” then “Shortcut” and type or paste this in the location box “C:\Windows\System32\cmd.exe” without the quotation marks assuming that Windows is installed in the C: Drive. This shortcut will then open a DOS window.

Commands we will be using in this guide

Note that text enclosed in <> is explanatory and is not to be typed. Also replace 4.2.2.1 with your selected DNS server.

dns server route list <lists all the current DNS servers>

dns server route add dns=4.2.2.1 metric=1 intf=Internet <adds a new DNS server in accordance with the server numbers you want. The metric value defines the priority. As the default priority is 10, use a number smaller than that to avoid your setting being overwritten by the automatically generated Plusnet ones.>

dns server route delete dns=4.2.2.1 <removes a DNS server from the list>

saveall <this command saves all the changes to non volatile memory otherwise on a reboot of the router all the changes will be lost>.

Some of the DNS servers which can be used are as follows

OpenDNS

208.67.220.220
208.67.222.222

Plusnet

212.159.13.49
212.159.13.50
212.159.6.9	<in my experience usually the primary DNS automatically allocated>
212.159.6.10	<in my experience usually the secondary DNS automatically allocated>

For guidance I would suggest using a Plusnet one first and an OpenDNS one second as this covers for the case where one or the other is having trouble. In this situation the metric would be 1 for the Plusnet one and 2 for the OpenDNS one thereby setting the priority as you want it. You could, of course, use any numbers you wish and as long as they are less than 10 they will have a higher priority than the automatic ones.

Step by Step Guide

Open DOS window

Type telnet 192.168.1.254

Username Administrator

Password blank (unless you have changed it)

Note: the Username and Password to use depends on the router you are using. Please see the guide that came with your router for the appropriate ones to use.

You should then see something like this

Username : Administrator
Password :
------------------------------------------------------------------------
______                   SpeedTouch 585
___/_____/\
/         /\               6.1.4.3
_____/__       /  \
_/       /\_____/___ \   Copyright (c) 1999-2006, THOMSON
//       /  \       /\ \
_______//_______/    \     / _\/______
/      / \       \    /    / /        /\
__/      /   \       \  /    / /        / _\__
/ /      /     \_______\/    / /        / /   /\
/_/______/___________________/ /________/ /___/  \
\ \      \    ___________    \ \        \ \   \  /
\_\      \  /          /\    \ \        \ \___\/
\      \/          /  \    \ \        \  /
\_____/          /    \    \ \________\/
/__________/      \    \  /
\   _____  \      /_____\/
\ /    /\  \    /___\/
/____/  \  \  /
\    \  /___\/
\____\/
------------------------------------------------------------------------

I will now use the commands to show the effects – note that these were done with the router off line so it doesn’t show the default Plusnet servers.

{Administrator}=>dns server route list
DNS Server       Source              Domain            Metric  Intf     State
208.67.220.220                                         1     Internet
{Administrator}=>dns server route add dns=212.159.13.50 metric=2 intf=Internet
{Administrator}=>dns server route list
DNS Server       Source              Domain            Metric  Intf     State
208.67.220.220                                         1     Internet
212.159.13.50                                          2     Internet
{Administrator}=>dns server route delete dns=212.159.13.50
{Administrator}=>dns server route list
DNS Server       Source              Domain            Metric  Intf     State
208.67.220.220                                         1     Internet
{Administrator}=>saveall
{Administrator}=>

[#2]

When applying additional DNS Servers, do you put in both
TCP/IPv4
&
TCP/IPv6
does Plus Net support both or only one?
This is what I have in my Vista settings.

[#3]

The only ones I've seen (e.g. on the connections settings page on the website) are IPv4 style and I'd be inclined just to stick with those.

[#4]

Plusnet do not support IPv6 so only the IPv4 ones do anything regardless as to whether they are Plusnet or OpenDNS servers

[#5]

I'd suggest using the Google DNS servers in preference to the OpenDNS ones which give sponsored results if you mistype a URL.

[#6]

Thanks. That's mostly clear enough.
However the example seems to only have a single DNS server. How does this relate to primary and secondary?
Do you set the primary one as metric=1 an the secondary one as metric=2 ?

[#7]

That is correct in that the primary DNS server is the one with the lowest metric and the secondary is the one with the next lowest.
I run with the primary Google DNS and the secondary Plusnet DNS set as described
Note that this article was written before the Google DNS servers became available.
They are 8.8.8.8 and 8.8.4.4

[#8]

Excellent guide, I'd suggest adding that it also works for the TG585 v8, only the Username 'admin' and password are different.
When wishing to reset back to the original DNS servers I had to use 'dns server route flush' as delete would not work.

[#9]

This is a most helpful page - thank you Oldjim.
How strange that we can't alter the DNS from the router's web interface. I've never come across a router that doesn't allow that.
While we're on the subject, there's a nifty little tool called Namebench which will find the best DNS servers for you. I was quite surprised to find that a couple of BT servers came out faster than both OpenDNS and Google. It comes out with a very helpful set of information. This is my public results page. http://namebench.appspot.com/id/6189025

[#10]

Also works for TG582n (as for TG585).

[#11]

Thank you for putting this together, especially in light of recent events, its good to put in a Backup DNS server just in case there's a repeat performance!
Falesia that nifty tool (Namebench) showed me that the default Plusnet servers were second best for me, with a BT server coming in first.

[#12]

Hey oldjim & community! I realise this is almost a dead thread but it is the best one I've found while trying to solve this problem. Thing is, I followed your instructions and when trying to delete the PlusNet dns routes (212.159.*) it says Failed to delete route. It allows me to add other dns routes so I've added Googles. Just wondering if you had seen this and maybe overcome it before?

[#13]

Could I bump this and ask if anyone's found a solution to moominboy's problem? I'm having the same now. I want to delete the Google DNS server (or give it a high metric) and I get the same error.

[#14]

Only way I could do it was
dns server route flush
which deletes all your connections, then adding the desired ones in again.

[#15]

To delete a route:
dns server route delete dns=212.159.13.50 intf=Internet

[#16]

I've changed the title of the article and the text to reflect that the article applies also to routers more recent than the Speedtouch range. Also added a note to use the Username and Password appropriate to the individual router as given in the guide that accompanied it.

[#17]

I would suggest using 'DNSBench' over several days to build a list of the fastest DNS servers seen by your system, and probably avoiding google, opendns (redirects unknowns) & level3.net (can be unreliable at busy times)

[#18]

Somewhat different commands on my TG582n (10.2.2.B.EH)
dns server forward list
dns server forward flush
dns server forward dnsset add set=0 dns=212.159.13.50 metric=9 intf=Internet

[#19]

Any way to do this on a mac?