Since commit 683a21b0a in Feburary 2011, iproute2 has been required for
new VLAN configuration. MACVLAN is also impossible to configure without
iproute2. However we did not check if iproute2 was actually in the
modules for a given interface, so it could end up hanging or giving
weird errors. Check for iproute2 before usage now.
X-Gentoo-Bug: 389437
X-Gentoo-Bug-URL: https://bugs.gentoo.org/show_bug.cgi?id=389437
Signed-off-by: Robin H. Johnson <robbat2@gentoo.org>
