[SOLVED] Second nic card won't work.

ravenswood · 02-18-2012, 09:19 AM

Hello,

Having a bit of trouble and hoping that someone here could help.

I'm setting up a physical machines using debian/kvm with two virtual machines for things like samba, mysql, bind, etc. The physical machine has two ethernet cards with eth0 being used for the public network (where users can access the servers on the same network they get the internet on), and eth2 being used for a private network (I am visioning that they will use the private network for cross talk to other servers and a NAS unit.btw eth1 just 'poofed' so it went to eth2).

The public network is in the 192.168.1.0/24 range. The private is in the 10.0.0.0/24 range.

The NAS has two ethernet sockets and a windows box can ping both private and public networks.

The problem I am having, the debian/kvm box can only ping the NAS on the public network, not the private.

The interfaces config file looks like:

Code:

auto lo br0 br1 eth0 eth2
iface lo inet loopback

# The primary network interface
#allow-hotplug eth0
#iface eth0 inet dhcp
iface eth0 inet manual
        hwaddr ether 1c:6f:65:d6:54:6b

iface br0 inet static
        address 192.168.1.140
        network 192.168.1.0
        netmask 255.255.255.0
        broadcast 192.168.1.255
        bridge_ports eth0
        bridge_fd 9
        bridge_hello 2
        bridge_maxage 12
        bridge_stp off
        gateway 192.168.1.1


iface eth2 inet manual
        hwaddr ether 00:12:17:55:c1:95

iface br1 inet static
        address 10.0.0.2
        netmask 255.255.255.0
        broadcast 10.0.0.255
        network 10.0.0.0
        bridge_ports eth2

route -n looks like:

Code:

Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
10.0.0.0        0.0.0.0         255.255.255.0   U     0      0        0 br1
192.168.1.0     0.0.0.0         255.255.255.0   U     0      0        0 br0
0.0.0.0         192.168.1.1     0.0.0.0         UG    0      0        0 br0

What could I be doing wrong? Is this a routing issue? I am lost here.

Can someone help?

Thanks so very much in advance.

business_kid · 02-18-2012, 10:42 AM

What about eth1?

Those things are usually about interrupts, or ownerships. If you can talk to it in the real system, the vm hasn't a chance of seeing it.

ravenswood · 02-18-2012, 11:12 AM

Eth1 just disappeared and eth2 appeared instead so I started using that. Can go in search of what made that happen. Didn't think it was that important.

anomie · 02-18-2012, 11:34 AM

I haven't set up a dual-homed Debian system, but on RHEL they require a bit of help from ip(8) for routes to work correctly.

Out of curiosity, what's the (summarized) reasoning for your network configuration? Neither of those subnets is publicly routable. They're both private (RFC 1918) subnets. The reason I'm asking: this looks overly complicated, unless there are some other pertinent details you have left out.

As for troubleshooting, I'd fire up tcpdump(8) on two separate terminals and observe packet behavior when you're doing your ping tests. That's often very revealing - on improperly configured dual-homed systems, packets aren't always exiting and entering on the interfaces you think they are.

Terminal 1:

Code:

# tcpdump -i eth0 icmp

Terminal 2:

Code:

# tcpdump -i eth2 icmp

ravenswood · 02-18-2012, 12:15 PM

This plan might be a bit too complex, yes. The idea was that on the 192. network there are all the users, thier traffic to and from the internet, file sharing, etc, while on the 10. network (with the second card) there would be traffic to and from various servers and storage device(s) only.

Figured this way I could move massive backup files back and forth plus have a master/slave database going without impacting the normal user network.

I'm sure open to ideas! If anyone has any suggestions please let me know!

Thanks much.

ravenswood · 02-18-2012, 01:27 PM

Dumb me. I give formal permission for you all to kick me in the shoulder. One must also make sure that the second nic card electrically functions.

Replaced second nic card, all works fine.