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Please send questions to the Bridge mailing list [1], I don't want to deal with problem reports in the wiki.Shemminger


Regarding RSTP (802.1w) support

Is the “unsupported RSTP implementation against the 2.4.19 uClinux kernel” or the current development towards 2.6 available somewhere?

I put a copy of what I got in but it is missing pieces and unusable.Shemminger

Getting the ip address for br0 via the dhcp protocol

I have a shitty ADSL modem with one ethernet port. I have a desktop and a couple of laptops, and in Windows XP I bridge eth0 and eth1 on my desktop and connect a laptop to eth1. Then I tell Windows to get an IP address for the bridge using dhcp. It works and I am able to use both my desktop and my laptop connected to my shitty modem.

Now, I have tried a gazillion different ways of doing this, and this is the only way that works at all. If I manually assign a fixed IP address to my ethernet port, it doesn't work. If I reboot from Windows XP to Linux, I have to power cycle the modem, else it refuses to talk to the computer. If I get an IP address for eth0 via dhcp in Linux, then bring down eth0, add it to the bridge, bring up br0 with the same IP that eth0 had, the modem refuses to talk to the desktop again.

While it's true that I could simply buy a better modem, a switch, a DLP projector and a new car, I'm going to be moving again in six months to a different continent so it's money out the window. Also, the fact is that bridging network interfaces and using dhcp to get an ip for the bridge is useful in other applications. (For instance, it lets me turn my laptop into an instant wireless access point connected to my modem. But only in Windows.)

So how do we assign the IP address for br0 via dhcp instead of via a fixed IP address?

Sloisel 14:10, 10 February 2006 (PST)

Isn't it more convenient to perform routing and NAT at the desktop host? It could be DHCP server on one interface and DHCP client on another. –Pilot 18:24, 12 February 2006 (PST)

Using dhcp works fine. Usually the problem is the default forwarding delay is 30 seconds. So just after you add a device to a bridge, it won't send anything. You can either wait or set forwarding delay to 0 first.

  # brctl setfd br0 0
  # brctl addif br0 eth0
  # dhclient br0

Sonos fork

Sonos, a company that makes a in house music distribution system, forked the bridges-util code. Their forked version is available here:

I didn't see a section on the main page that this would obviously fit into, so I'm mentioning it here instead. JesseW 23:28, 6 June 2006 (PDT)

I looked that is old code, it won't work with current 2.6 systems. I don't seem any differences from older bridge (2.4 based) utilities code Shemmminger

Bridge works, but how to browse, etc?


I've got a bridge up on my Suse 10 box. The 2 NICs are connected, and my main box (Suse 10.1) can print to the printer on the other side of the bridge box. Everything pings everywhere. Cool!

I used the basic configuration:

 # ifconfig eth0
 # ifconfig eth1
 # brctl addbr mybridge
 # brctl addif mybridge eth0
 # brctl addif mybridge eth1
 # ifconfig mybridge netmask

On the bridge box, I can browse to an Apache-served web page on my main box, but cannot browse to the outside Internet. Wonder what is wrong? Any suggestions?

Is there some way to configure the bridge as a network device?

Thanks DoubtinTom

Answer, you need to add a default route to you gateway (probably

 # route add -net default gw

Please send questions to the Bridge mailing list [2].

Russian Translation

I have translated page Bridge into Russian. You can find my translation on the page[3] Please tell me, where can I post this link?

I hope my work will be useful for users with poor knowledge of English.

Thanks –Igorchubin 06:52, 4 February 2007 (PST)

Please put a link at start of page to your site, maybe you will start a trend and other pages and languages will be available as well.

networking/talk/bridge.txt · Last modified: 2016/07/19 01:22 (external edit)