Comment 20 for bug 1621507

After looking into this more (and working on Bug #1629972 some), there are couple of issues with the new configure_networking:

1. since it checks only for the existence of /run/net-${DEVICE}.conf, and the dhclient scripts ALWAYS (even on failure) create it, it will try to get a lease exactly once before bailing out. Ideally, if both ipv4 and ipv6 are present on the vlan, then both would be configured and (as is done) present in the net-$DEV.conf file.

2. Since router-advertisements are needed for the on-link indication (and routes), ipv6 configuration via dhcp should wait until such time as there is at least a (non-fe80) route for some ipv6 cidr on $DEVICE (which RA should create). This will eliminate the iscsi-timeout errors that we see when configure_networking() returns before RA configures routing. Note that a default route is not necessary. Note also that it should timeout on the RA if it doesn't show up in a reasonable time, complain that it got no RA, and then _not_ bring up ipv6 on the interface (RA is required, as per Bug #1609898)