Does CDRouter support stacked VLANs on the WAN?

Yes, CDRouter supports 802.1ad VLAN stacking on the WAN.

When stacked VLAN support is enabled within CDRouter, a maximum of one outer tag (S-tag or service tag) and one inner tag (C-tag or customer tag) can be configured. In addition, priorities can be set for both the outer and inner tags. Five new testvars have been added for stacked VLAN configurations:

testvar enableVlanStacking               yes

testvar wanInnerVlanId                   100
testvar wanInnerVlanPriority             0

testvar wanOuterVlanId                   200
testvar wanOuterVlanPriority             0
testvar wanOuterVlanQinQ                 no

By default, CDRouter follows the 802.1ad standard of VLAN stacking, setting the TPID (Tag Protocol ID) of the S-tag to 0x88a8. The C-tag is an 802.1Q VLAN tag with TPID 0x8100.

Some older devices support “QinQ” style VLAN stacking, using 802.1q VLAN tags (0x8100) for both the outer and inner tags. Setting the wanOuterVlanQinQ testvar is set to “yes” will cause CDRouter to use “QinQ” style VLAN stacking when working with these devices.

testvar enableVlanStacking               yes

testvar wanInnerVlanId                   100
testvar wanInnerVlanPriority             0

testvar wanOuterVlanId                   200
testvar wanOuterVlanPriority             0
testvar wanOuterVlanQinQ                 yes

When stacked VLANs are enabled the testvars wanVlanId and wanVlanPriority are ignored, and any packets that are received on the WAN without the specified outer and inner tags will be dropped.