First off, don't assign the bridge an IP on the LAN try is as ifconfig br0 up
if you MUST assign an IP, use 0.0.0.0 another hint, unless you are using a second bridge, be sure that the STP is disabled also be sure that you have the ipv4 packet forwarding turned on You have left out alot of details that are normally needed to answer your questions, such as what your kernal version is, which patches you have applied, etc. Best regards Gari... JavaBeanz.com On Wednesday 06 March 2002 04:30 pm, you wrote: > Hello. I'm trying to get an ethernet bridge running, and after > following the simple instructions in the FAQ I'm stuck. > > My test bridge machine has three network cards: > > - eth0 is the "normal" interface, a SIS900 on the motherboard, and has > an IP address (10.134.1.188) assigned by DHCP. Everything works fine > with that. > > - eth1 and eth2 are both intel eepro100 cards, untouched by the system > startup scripts. > > The network config is: I have a small 10/100 switch on my desk with an > uplink to the company router. Both eth0 and eth1 are attached to the > switch. eth2 is attached to a single machine I'll call "client". > > |--------| |-----------------------| |--------| > | switch |<------->|eth0 bridge machine | | client | > | > | |<------->|eth1<------------->eth2|<-->|--------| > | > |--------| |---------------------- | > > The goal is to have my bridge machine do all it's own network > communication through eth0, and have an eth1<-->eth2 bridge which allows > the client to see the network. (Later on I plan to add filtering to > this bridge, but for now it's just a stock 2.4.19-pre2 kernel without > any filtering or firewalling options.) > > I don't want the bridge machine to do any of it's own communication > using the bridge. This is important: the bridge interfaces must be used > ONLY for bridging. If the bridge machine wants to talk to the client, > it should communicate out eth0 to the switch. > > So, to begin with the bridge machine is working fine. The startup > scripts configured eth0 as 10.134.1.188, it is running, and the eth1 and > eth2 cards for the bridge don't even have drivers loaded. > > Then, as root I do this: > > # modprobe eepro100 > > (driver finds both cards, and ifconfig -a now shows eth1 and eth2) > > # brctl addbr br0 > > (ifconfig -a now also shows br0) > > # brctl addif br0 eth1 > # brctl addif br0 eth2 > > dmesg shows both cards entering promiscuous mode, and "brctl show" > indicates: > > bridge name bridge id STP enabled interfaces > br0 8000.0002b3102680 yes eth1 > eth2 > > So I try to bring up the bridge by assigning it an unused IP > address on the subnet (I still don't understand why this is > necessary, by the way, but that's what the instructions say): > > # ifconfig br0 10.134.1.2 > > Now, I see: > # ifconfig -a > br0 Link encap:Ethernet HWaddr 00:02:B3:10:26:80 > inet addr:10.134.1.2 Bcast:10.255.255.255 Mask:255.0.0.0 > UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 > RX packets:0 errors:0 dropped:0 overruns:0 frame:0 > TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 > collisions:0 txqueuelen:0 > RX bytes:0 (0.0 b) TX bytes:0 (0.0 b) > > [ as well as eth0, eth1, eth2, and lo. Everything looks correct, > eth1 and eth2 do not have IP addresses of their own.] > > So everything looks right, I think. The problems are: > > 1. "route -n" on the bridge machine shows that the bridge has been > added to the routing table: > > Kernel IP routing table > Destination Gateway Genmask Flags Metric Ref Use Iface > 10.134.0.0 0.0.0.0 255.255.254.0 U 0 0 0 eth0 > 10.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 br0 > 127.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 lo > 0.0.0.0 10.134.0.1 0.0.0.0 UG 0 0 0 eth0 > > I don't want that. In fact, the bridge machine can't communicate > over the net anymore, it seems to have quit using eth0. If I try > to delete that route, "route del 10.0.0.0" I get > SIOCDELRT: No such process > > 2. Packets are not forwarded. > > When the client machine on the eth2 side of the eth1--eth2 bridge tries > to DHCP, with the DHCP server on the eth1 side of the bridge, nothing > crosses the bridge. > > "tcpdump -i br0" only shows arp from the bridge machine trying to find > the nameserver (10.128.0.50): > "16:15:31.970200 arp who-has 10.128.0.50 tell 10.134.1.2" > but no other packet traffic... > > "ifconfig -a" shows the TX and RX counts on eth1 and eth2 stay at zero, > while the TX count on br0 seems to just show the arp packets going out. > > Any hints on how to make this work? I'm stuck. > > Thanks... > > Torrey Hoffman > [EMAIL PROTECTED] > > > > _______________________________________________ > Bridge mailing list > [EMAIL PROTECTED] > http://www.math.leidenuniv.nl/mailman/listinfo/bridge _______________________________________________ Bridge mailing list [EMAIL PROTECTED] http://www.math.leidenuniv.nl/mailman/listinfo/bridge
