uml and multiple network segments

bartman
2006-07-13

I am doing a lot of network testing and require multiple virtual networks created for my UML’s. Debian’s uml-utilities package does not currently support bringing up multiple network segments, although the uml_switch daemon can be ran multiple times. In such a setup each uml_switch is associated with it’s own tapX device and maintains one network segment.

I modified two files:

And filed bug 378166.

The remaining bit to configure for you is your /etc/network/interfaces to assign the right IPs to the tapX devices…

    auto tap0
    iface tap0 inet static
            address 192.168.10.254
            netmask 255.255.255.0
            tunctl_user uml-net
            up echo 1 > /proc/sys/net/ipv4/conf/tap0/forwarding

    auto tap1
    iface tap1 inet static
            address 192.168.20.254
            netmask 255.255.255.0
            tunctl_user uml-net
            up echo 1 > /proc/sys/net/ipv4/conf/tap1/forwarding

And finally you have to pass the right configuration to your uml instances. Here is an example of what my uml startup looks like:

./east.linux \
        mode=skas0 \
        mem=256M \
        ubd0=east.fs \
        root=/dev/ubda 
        eth0=daemon,,unix,/var/run/uml-utilities/uml_switch.tap0.ctl \
        eth1=daemon,,unix,/var/run/uml-utilities/uml_switch.tap1.ctl \
        con0=fd:0,fd:1 
        umid=east

And that will start a UML instance connected to two network segments.

Now, onto Openswan testing.

Tags:

Uml
Linux