Kb215
Emulab FAQ: Testbed Operations: How does Emulab find the control interface on Linux?
> I somehow forgot how an RHL9 disk image finds the > control interface and fills out the /var/emulab/boot/controlif file. > I thought, the mechanism is the same as the one on FreeBSD on which > /usr/local/etc/emulab/control_interface is a script that uses the > result of nodetype and etc.
In the current world order, we DHCP on all interfaces and take the one that first responds to be the control net. So /etc/dhclient-exit-script (which should be on both BSD and Linux) is the one that creates the controlif file.
control_interface is a dreg, all it does now is cat the controlif file.
The way that we actually force dhcp on all interfaces is hideous and perverted. See /etc/sysconfig/network-scripts/ifcfg-eth99.