[SATLUG] kvm networking
bruce.dubbs at gmail.com
Mon Jan 23 17:04:31 CST 2012
I'm looking for help but this is pretty long. Please trim any replies.
I am exploring kvm. It is interesting technology, but I'm having a
little problem figuring out how to set up networking. I have been able
to bring up a virtual system and install Fedora 16 on it. I can then
start that instance with:
qemu -hda vdisk.img -m 1G -net nic -net user
This provides network connectivity from the virtual system to the
What I would like to do is get connectivity from the host to the client
for an ssh connection. The client has an ip address of 10.0.2.15/24 and
a gateway of 10.0.2.2.
The host, on the other hand has no knowledge of any 10.x.x.x address.
Some documentation I've seen talks about using iptables/routing:
sysctl -w net.ipv4.ip_forward=1
route add -host <ip-of-client> dev <tap-device>
route add -host <ip-of-host> dev <network-interface>
route add default gw <ip-of-host>
I've tried this. I have the following on the host:
#ls -l /dev/kv* /dev/net/*
crw-rw---- 1 root kvm 10, 232 Jan 23 13:37 /dev/kvm
crw-rw-rw- 1 root root 10, 200 Jan 23 13:37 /dev/net/tun
all default eth0 lo sit0 tap0 tunl0
tap0 Link encap:Ethernet HWaddr 02:E2:D5:41:36:A3
UP BROADCAST 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
RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
0.0.0.0 192.168.0.1 0.0.0.0 UG 0 0 0 eth0
10.0.2.15 0.0.0.0 255.255.255.255 UH 0 0 0 tap0
192.168.0.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0
And the following on the client:
192.168.0.22 0.0.0.0 255.255.255.255 UH 0 0 0 tap0
However, there is is no direct connectivity between the host and client.
I suspect that it is due to the qemu options -net nic -net user, but I
can't seem to figure out what to set.
Has anyone worked with this and figured it out?
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