Bridging interfaces and the internet

[Justin Willmert]

I just set up a desktop with two network cards and have got a bridge 
working between the two. That is not what my problem lies in though. I 
would like for the box to be able to connect to the internet also, but 
if I understand what I've set up correctly, I can't do that with my 
current setup. When I've tried to give one of the network cards an IP 
address, nothing but lo works, so I know there's something missing. I'll 
add my configuration at the bottom, but shortly, br0 is configured with 
an IP address, and eth0 and eth1 have none. Now, I know br0 is capable 
of at least a network connection because as I type this, I'm currently 
SSHed into into the box, but if I try to ping anything, all the packets 
are lost.

OK, so here are some of my thoughts and possible hints to a solution:
    1) My routing tables need another route, so I just figure out how to 
configure that and add a route.
    2) br0, eth0, and eth1 are incapable of an internet connection, in 
which case I need to create a virtual interface that can connect as if 
it were a separate interface that does the internet connecting.
    3) (Very unsure, but...) use a alias interface to allow both eth0 
without an IP address to make br0 happy and give eth0:0 an IP address to 
allow me to connect to the internet.

Thanks for any help,
Justin Willmert


===================== ifcfg-br0 =====================
DEVICE=br0
TYPE=Bridge
BOOTPROTO=static
IPADDR=192.168.2.75
NETMASK=255.255.255.0
ONBOOT=yes
DELAY=0
STP=off


===================== ifcfg-eth0 =====================
DEVICE=eth0
BOOTPROTO=static
HWADDR=00:04:5A:50:A6:38
ONBOOT=yes
TYPE=Ethernet
BRIDGE=br0


===================== ifcfg-eth1 =====================
DEVICE=eth1
BOOTPROTO=static
HWADDR=00:04:5A:4E:BC:02
ONBOOT=yes
TYPE=Ethernet
BRIDGE=br0


===================== static-routes =====================
any: net 127.0.0.0 netmask 255.0.0.0 dev lo
any: net default gw 192.168.2.2 dev br0


===================== output of `route` =====================
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use 
Iface
192.168.2.0     *               255.255.255.0   U     0      0        0 br0
169.254.0.0     *               255.255.0.0     U     0      0        0 br0
127.0.0.0       *               255.0.0.0       U     0      0        0 lo
             ===== 10 second or so delay here =====
default         192.168.2.2     0.0.0.0         UG    0      0        0 br0


===================== output of `ifconfig` =====================
br0       Link encap:Ethernet  HWaddr 00:04:5A:4E:BC:02
          inet addr:192.168.2.75  Bcast:192.168.2.255  Mask:255.255.255.0
          inet6 addr: fe80::200:ff:fe00:0/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:2763 errors:0 dropped:0 overruns:0 frame:0
          TX packets:715 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:178695 (174.5 KiB)  TX bytes:63849 (62.3 KiB)

eth0      Link encap:Ethernet  HWaddr 00:04:5A:50:A6:38
          inet6 addr: fe80::204:5aff:fe50:a638/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:100399 errors:0 dropped:0 overruns:0 frame:0
          TX packets:8542 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:11462669 (10.9 MiB)  TX bytes:3050387 (2.9 MiB)
          Interrupt:12 Base address:0xc000

eth1      Link encap:Ethernet  HWaddr 00:04:5A:4E:BC:02
          inet6 addr: fe80::204:5aff:fe4e:bc02/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:9626 errors:0 dropped:0 overruns:0 frame:0
          TX packets:41708 errors:13 dropped:0 overruns:0 carrier:13
          collisions:0 txqueuelen:1000
          RX bytes:3182447 (3.0 MiB)  TX bytes:7203127 (6.8 MiB)
          Interrupt:10