RHEL6 (later Fedora releases, and some other distros) recently made some things a bit screwy with the naming of network interfaces… some mainboard embedded NIC’s show up as em1, em2. instead of eth0, eth1 ….
Most of the time this is not a problem, however FlexLM definitely has a problem with this as it is hard-coded to look for the MAC address of eth0…. period, nothing else will do.
This is all caused by a package called biosdevname, before removing this package which is installed by default trying to resolve it, there is a better way to not break things or cause dependency issues further down the road.
Best way to solve this I have found follows:
# cp /etc/grub.conf /etc/grub.bak #get smart here and make a backup!
Add biosdevname=0 to the kernel boot arguments in /etc/grub.conf.
Rename /etc/sysconfig/network-scripts/ifcfg-em1 to /etc/sysconfig/network-scripts/ifcfg-eth0, changing the line DEVICE=”em1″ to DEVICE=”eth0″ (Repeat for any additional interfaces, BONDed interfaces should continue to function as expected.
Delete /etc/udev/rules.d/70-persistent-net.rules (if it exists)
Now FlexLM should detect the MAC of eth0 because…. well… eth0 now exists, which tends to make things much happier.