[TriLUG] Networking and Fedora

Joseph Tate dragonstrider at gmail.com
Wed May 26 13:22:54 EDT 2010


Note that I'm trying to route to the host, not a vm guest.

$ brctl show
bridge name     bridge id               STP enabled     interfaces
br0             8000.001d0999710f       no              eth1
                                                        vnet0
                                                        vnet1
                                                        vnet2
virbr0          8000.000000000000       yes
$ route -n
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
10.2.2.0        0.0.0.0         255.255.255.0   U     0      0        0 eth0
10.2.2.0        0.0.0.0         255.255.255.0   U     0      0        0 br0
192.168.122.0   0.0.0.0         255.255.255.0   U     0      0        0 virbr0
169.254.0.0     0.0.0.0         255.255.0.0     U     1002   0        0 eth0
0.0.0.0         10.2.2.1        0.0.0.0         UG    0      0        0 br0


Port forwarding works to several other computers behind the router,
but does not work to this Fedora 12 box.

On Wed, May 26, 2010 at 12:28 PM, Justis Peters <jtrilug at indythinker.com> wrote:
> Are you doing anything special with your routing tables? Is it just a
> single default gateway? Can you ping the VM from the gateway itself?
>
> Have you tried port forwarding to any other hosts, preferably ones with
> simpler networking configs? Port forwarding to the virtualization host
> would be great, because that would confirm half the path.
>
> Can you give us the output of "brctl show", just to make sure it's sane?
>
> Also, check the MTU on the VM to make sure that it's no longer than the
> 1500 that's set on br0. You may also want to research what the proper
> setting is for "checksum offloading" via ethtool. I'm not sure what the
> recommended path is on KVM, but I had to disable it on my Xen domUs in
> order to resolve intermittent networking failures.
>
> I'll be offline for a few hours, because I'm going to watch the NC
> Senate's Finance Committee meeting. They're supposed to vote on S1209
> today and I'm there to oppose it. The proposed bill would stifle
> attempts at municipal broadband infrastructure, by requiring all
> financing to go through general obligation bonds via a ballot measure in
> a general election.
>
> Kind regards,
> Justis
>
> Joseph Tate wrote:
>> Using KVM, guests are bridged:
>>
>> br0       Link encap:Ethernet  HWaddr 00:1D:XX:XX:XX:XX
>>           inet addr:10.2.2.8  Bcast:10.2.2.255  Mask:255.255.255.0
>>           inet6 addr: fe80::21d:9ff:fe99:710f/64 Scope:Link
>>           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
>>           RX packets:1676072 errors:0 dropped:0 overruns:0 frame:0
>>           TX packets:74716 errors:0 dropped:0 overruns:0 carrier:0
>>           collisions:0 txqueuelen:0
>>           RX bytes:554784107 (529.0 MiB)  TX bytes:10909168 (10.4 MiB)
>>
>> eth0      Link encap:Ethernet  HWaddr 00:07:XX:XX:XX:XX
>>           inet addr:10.2.2.4  Bcast:10.2.2.255  Mask:255.255.255.0
>>           inet6 addr: fe80::207:e9ff:fe0f:4c39/64 Scope:Link
>>           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
>>           RX packets:9110464 errors:0 dropped:0 overruns:0 frame:0
>>           TX packets:13503488 errors:0 dropped:0 overruns:0 carrier:0
>>           collisions:0 txqueuelen:1000
>>           RX bytes:846113634 (806.9 MiB)  TX bytes:17866625825 (16.6 GiB)
>>
>>
>> On Wed, May 26, 2010 at 11:44 AM, Justis Peters <jtrilug at indythinker.com> wrote:
>>
>>> What are you using for virtualization and how is its networking
>>> configured between the host network and guest VMs? Bridged? Routed? NAT?
>>>
>>> Kind regards,
>>> Justis
>>> --
>>> TriLUG mailing list : http://www.trilug.org/mailman/listinfo/trilug
>>> TriLUG FAQ          : http://www.trilug.org/wiki/Frequently_Asked_Questions
>>>
>>>
>>
>>
>>
>>
>
> --
> TriLUG mailing list : http://www.trilug.org/mailman/listinfo/trilug
> TriLUG FAQ          : http://www.trilug.org/wiki/Frequently_Asked_Questions
>



-- 
Joseph Tate
Personal e-mail: jtate AT dragonstrider DOT com
Web: http://www.dragonstrider.com



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