Two routers, nfs and ip addresses.

My main network is on a wired router. I have the internet coming into that router. Since I wanted to use a laptop in the bedroom, I added a wireless router. To do this, I plugged a lead from the wired router into the Internet input on the wireless router. I assigned the wireless a static address on my wired network and use dhcp on the wireless network itself.

Everything works fine except for one thing: I can’t access machines on the wireless network from machines on the wired network. I AM able to access machines on the wired network from machines on the wireless network. I often need to sync files from the laptop (wireless) with my desktop (wired). To do this, I use NFS. I am able to copy files from the desktop to the laptop when on the laptop, but I can’t copy files from the laptop to the desktop using the desktop machine. Is there any way to do this?

Your wireless router most likely has a firewall in it. Also it will NAT the wireless network onto the wired network. Similar situation to when you use a router to get onto the Internet: you can easily access outside resources, but outside is prevented from accessing inside. In this case, where the wireless network is concerned, the “outside” is the wired network.

You would have to add portforwarding rules to the wireless router and you will have to assign your laptop a fixed IP on the wireless network for the portforwarding to work. For NFS this is tricky because NFS is actually a whole bunch of services, and some of them normally use floating ports, and will have to be pinned to fixed ports. Maybe it might be a much smaller hassle if you use a protocol with a single port, like SSH.

Some not all wireless routers have a gateway mode that makes it function like a switch so comps that connect to the wap pull IPs from the base wired router. You will have to delve into the routers settings.

There is a choice on the wireless setup menu to configure it as a DMZ server. Would this have any effect? Might it work better if instead of plugging the wired router into the wireless network as the internet input, I plugged it in as a regular network node. If so, I would really have little idea as how to configure it

The best approach is to “convert” your wireless router to a wireless access point. Access points drop the router functionality, acting effectively as a bridge between your wired and wireless network. There are several ways to handle this

  • See if your wireless router can be configured to be an access point.
  • If not, see if OpenWRT runs on your wireless router. I believe it might be able to be configured as an access point
  • Connect your wired router into the LAN port of your wireless router. This requires care with the wireless router:
  • Ensure it does not act as a DHCP server
  • Ensure its LAN has an IP address on the same subnet as your wired router’s LAN


This sounds like the way to go. Right now I have my network set up with static IP addresses to accomodate NFS. Do I need to give computers accessing through the wireless static addresses? Or, can I convert the whole NFS network to DHCP using the wired router as the DHCP server? If I did this, would NFS still work?

No, Yes, Yes (but slowly to a wireless client)

Your limitations will be driven by the software you choose to run on your routers. Any access point software should be OK.

A single network can have multible segments (e.g., wired and wireless) which are connected via a bridge (access point in your case). You can mix static IP and dynamic IP on the same network. The network engineer must ensure the range assigned for staticly assigned addresses does not overlap with the dynamic IP address range. A single DHCP server can assign both dynamic and static IP address. Static IP addresses can be obtained via DHCP or a “script” on the computer. NFS has nothing to do with static or dynamic IP address.

So, the addresses will automatically be associated with the appropriate host names so that NFS will access them. I’m only asking because when I set up this network (albeit under SUSE 9.1 ), I could not make NFS work without using static addresses and a manually edited HOSTS file associating the static addresses with the appropriate host names. Now I’m using 11.1 so I suppose things have improved.

I will use an example from a set up I have. First, you need a machine to serve the purpose of the DHCP and DNS server. You can use a standard router or one loaded with something like OpenWRT or a Linux machine with your favorite distribution. I’ll give an example in the later case. At a minimum, you should use a package like dnsmasq to serve as the DNS server. Dnsmasq can also server as a DHCP server. However, I turn dnsmasq’s DHCP functionality off and use dhcp-server instead. It works better with diskless client. Dnsmasq on the router uses the /etc/hosts file to map hostname and IP address. This is easier than bind.

Dhcp-server use the file /etc/dhcpd.conf … here is an example that dishes out static and dynamic ip address.

ddns-update-style               none;
use-host-decl-names             on;
default-lease-time              3600;
max-lease-time                  7200;
option domain-name              "";
option etherboot-signature      code 128 = string;
option kernel-parameters        code 129 = text;
option etherboot-signature code 128 = string;
option kernel-parameters code 129 = text;
option log-servers    ;

subnet             netmask {
  # This is for dynamic addresses
  option broadcast-address;
  option routers    ;
  option domain-name-servers;
  option time-servers;

group {
  # This machine has a staic IP address
  host das-cpu {
    hardware ethernet           00:20:9d:07:16:97;
    fixed-address     ;

Thanks, this helps a lot.