On 04/15/2011 01:13 PM, Alex wrote:> Hi,
> I have a fc14 box with two interfaces that I'm having some difficulty
> setting up a bridge properly. I have a few kvm guests set up and
> running, but I've switched from using NetworkManager to using standard
> networking with a bridge. I've modified the ifcfg-eth0 and created
> ifcfg-br0 as per the standard documentation, but I think I'm having
> routing problems. This is what the network looks like:
>
> [root at fc14 ~]# route
> Kernel IP routing table
> Destination Gateway Genmask Flags Metric Ref Use
Iface
> 68.195.XXX.40 * 255.255.255.248 U 0 0 0 br0
> 192.168.1.0 * 255.255.255.0 U 0 0 0
eth1
> 192.168.125.0 * 255.255.255.0 U 0 0 0
virbr0
> link-local * 255.255.0.0 U 1003 0 0
eth1
> link-local * 255.255.0.0 U 1004 0 0 br0
> default ool-44c3c129.st 0.0.0.0 UG 0 0 0 br0
>
> br0 Link encap:Ethernet HWaddr 40:61:86:4E:84:09
> inet addr:68.195.XXX.42 Bcast:68.195.XXX.47
Mask:255.255.255.248
> inet6 addr: fe80::a0e7:ecff:fefd:340a/64 Scope:Link
> UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
> RX packets:3883 errors:0 dropped:0 overruns:0 frame:0
> TX packets:3579 errors:0 dropped:0 overruns:0 carrier:0
> collisions:0 txqueuelen:0
> RX bytes:1818327 (1.7 MiB) TX bytes:590720 (576.8 KiB)
>
> eth0 Link encap:Ethernet HWaddr 40:61:86:4E:84:09
> inet6 addr: fe80::4261:86ff:fe4e:8409/64 Scope:Link
> UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
> RX packets:3891 errors:0 dropped:0 overruns:0 frame:0
> TX packets:3551 errors:0 dropped:0 overruns:0 carrier:1
> collisions:0 txqueuelen:1000
> RX bytes:1873169 (1.7 MiB) TX bytes:588302 (574.5 KiB)
> Interrupt:42
>
> eth1 Link encap:Ethernet HWaddr 00:0E:0C:3B:36:F4
> inet addr:192.168.1.1 Bcast:192.168.1.255 Mask:255.255.255.0
> inet6 addr: fe80::20e:cff:fe3b:36f4/64 Scope:Link
> UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
> RX packets:7622 errors:0 dropped:0 overruns:0 frame:0
> TX packets:6936 errors:0 dropped:0 overruns:0 carrier:0
> collisions:0 txqueuelen:1000
> RX bytes:1062687 (1.0 MiB) TX bytes:4304984 (4.1 MiB)
>
> virbr0 Link encap:Ethernet HWaddr E6:ED:D2:6E:58:5C
> inet addr:192.168.125.1 Bcast:192.168.125.255
Mask:255.255.255.0
> 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)
>
> vnet0 Link encap:Ethernet HWaddr FE:54:00:67:2C:4C
> inet6 addr: fe80::fc54:ff:fe67:2c4c/64 Scope:Link
> UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
> RX packets:5 errors:0 dropped:0 overruns:0 frame:0
> TX packets:391 errors:0 dropped:0 overruns:0 carrier:0
> collisions:0 txqueuelen:500
> RX bytes:300 (300.0 b) TX bytes:23358 (22.8 KiB)
>
> I've left out the loopback for simplicity. The problem is that I
can't
> reach the br0 device from a server on the eth1 device (the 192.168.
> network).
Since the bridge is attached to the 68.195 network, you won't be able to
reach it from the 192.168.1 network unless this system (or another one)
is configured as a router. To use it as a router you will need to
enable net.ipv4.ip_forward in /etc/sysctl.conf (echo '1' >
/proc/sys/net/ipv4/ip_forward) and then either run a dynamic routing
protocol or setup static routes on any other system that wants to reach
it from the 192.168.1 network. The static routes for 68.195.xxx should
point at 192.168.1.1.
Nataraj> Is this a routing issue? Should I also add the eth1 device to the
> bridge? If so, how would I do that?
>
> Also, can you explain under what circumstances a tun device would be
> used? Does that have any relation to bridging?
>
> Thanks,
> Alex
>
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