We've had a small ethernet connected via ADSL router for some years, but always used static IPs and run bind9 on one of the machines. I've just changed to DHCP, to make things easier with transient clients. The ADSL router is a Netgear DG834G wireless+wired firewall router ADSL modem. Access to the internet is working from all machines on the network. The router also provides internal DNS to one windows client on the network, but not to the Linux boxes. The Linux boxes get no DNS, and it appears to only know some of them by name. I need help to correct the set up of the Linux boxes so that the internal DNS functions.

At present, I have tried to configure the Linux boxes identically, but they are behaving differently, as follows:

machine OS visible to gets local
name router as DNS info

atticus gentoo unknown no
bigfoot windows bigfoot yes
bordello sid bordello no
potty sid unknown no
ramon macOS ramon
tiramisu sarge unknown no
xenos sarge -- no this box is invisible to all but windows

The webserver on xenos refuses connection to other linux boxes when addressed by IP number. I am really baffled by the fact that the windows box can share files on it even though the router doesn't list it as existing at all. Can anyone suggest why some of the linux boxes show as 'unknown'? Can anyone help with how to get local dns info to the linux boxes?