DNS via ADSL modem/router doesn't play well with DHCP

Haris Peco snpe at snpe.co.yu
Sun Oct 9 00:51:19 UTC 2005

set your ubuntu like caching and forward DNS server
- server for local address (all your DHCP and router address) and
forwarder to your ISP DNS server (you can do it like true DNS, but forwarder work 
quicker, becuase your ISP is quicker, probably) - then set DNS server on all machine to
- it work better (quicker) than router's redirect dns

On Saturday 08 October 2005 10:02 pm, Robbo wrote:
> On Sat, 2005-10-08 at 15:14 +0100, Neil Woolford wrote:
> > I have a Linksys ADSL2MUE modem, running into a WRT54G wireless/wired
> > router.
> > 
> > Currently the modem is set as DHCP server and gateway between local
> > network and internet.  The modem picks up all the appropriate
> > information from the ISP, including the two static DNS addresses.  It
> > then sets up attached computers via DHCP with itself as DHCP server,
> > gateway address *and* DNS server address.  (All
> > 
> > My laptop, running Windows 98SE, works flawlessly with this and has no
> > trouble reaching the DNS via the local alias.  Winipcfg shows
> > as the DNS address.  So it appears that the modem/router is
> > forwarding domain name queries from the windows machine to the real DNS
> > addresses that it has obtained from the ISP and is then passing the
> > results back.
> > 
> > Unfortunately this doesn't work under Ubuntu (Breezy preview, 5.10 at
> > the moment but also previous versions).  Domain name queries to
> > just don't get answered.  Manually inserting the ISP
> > provided DNS addresses via the System>~Administration>Network gui gets
> > the system going again, but is overwritten the next time DHCP leases are
> > renewed.
> > 
> > I have followed the instructions on Dennis Kaarsemaker's wiki page
> > https://wiki.ubuntu.com/StaticDnsWithDhcp and set the system to prepend
> > the static DNS addresses and not overwrite them, so I do have a working
> > fix for the problem as far as my desktop machines go.
> > 
> > My question really is;  are others experiencing similar problems, or is
> > the difficulty a peculiarity of the Linksys ADSL2MUE?  If the problem is
> > widespread, can anything be done to fix it without editing config files?
> I've seen this issue before with a friends router (forget the make),
> after a while googling we found that the issue was a bug with the router
> and not Ubuntu (even though the router ran linux!).  The solution was to
> upgrade the router to the latest firmware.

More information about the ubuntu-users mailing list