Date

If you want VLAN (802.1q) to work with Fedora 17 NetworkManager setups, the configuration for the VLAN interface should NOT contain TYPE=Ethernet

If it does, it will fail. Hard.

So, this (example) is a working one:
ifcfg-em1.1:

VLAN=yes
DEVICE=em1.1
REORDER_HDR=yes
PHYSDEV=em1
UUID=73771fae-1cdc-b68b-632c-312f9aa400f7
NAME="Vlan 1"
HWADDR=8C:89:A5:C1:1A:C2
BOOTPROTO=dhcp
# TYPE=Ethernet
DEFROUTE=no
USERCTL=no
IPV4_FAILURE_FATAL=yes
IPV6INIT=no
ONBOOT=yes
PEERDNS=yes
PEERROUTES=yes
NM_CONTROLLED=yes

ifcfg-em1:

DEVICE=em1
PHYSDEV=em1
VLAN=yes
NAME="External"
HWADDR=8C:89:A5:C1:1A:C2
UUID="b503e152-be11-47b4-ac42-1fbf2f7d882c"
BOOTPROTO=dhcp
ONBOOT=yes
TYPE=Ethernet
USERCTL=no
IPV6INIT=yes
IPV6_AUTOCONF=yes
IPV6_DEFROUTE=yes
IPV6_FAILURE_FATAL=no
DEFROUTE=yes
IPV4_FAILURE_FATAL=yes
PEERDNS=yes
PEERROUTES=yes
IPV6_PEERDNS=yes
IPV6_PEERROUTES=yes
IPV6_PRIVACY=rfc3041
NM_CONTROLLED=yes