Support for IPv6 GRE tunnels require configuration of local IPv6 tunnel end-point address under wlan-gw configuration on the group-interface. The transport for L2oGRE (or L2VPNoGRE) packet is IPv6 as shown below. The outer IPv6 header contains the value 0x2F (GRE) in its Next Header field. GRE header contains protocol Ethernet (0x6558) or Ethernet-over-MPLS (0x8847) as in the case IPv4 GRE.
IPv6 Transport for L2oGRE Packet:
+-----------------------------------+
| |
| IPv6 Header |
| |
+-----------------------------------+
| |
| GRE Header |
| |
+-----------------------------------+
| |
| UE Ethernet Packet |
| |
+-----------------------------------+
A single wlan-gw endpoint instance on the group-interface can have both IPv4 and IPv6 address configured as shown below. Inter-AP mobility between IPv4 and IPv6 only APs is supported in this scenario.
IPv6 Endpoint Configuration for WLAN-GW:
service
vprn 300 customer 1 create
group-interface "grp-intf-1" wlangw create
wlan-gw
gw-addresses
address 10.1.1.4
address 2001:db8:
exit
gw-ipv6-address 2001:db8::0
mobility
hold-time 0
trigger data iapp
exit
egress
shaping per-tunnel
exit
tcp-mss-adjust 1000
vlan-tag-ranges
range start 100 end 100
data-triggered-ue-creation
retail-svc-id 402
exit
exit
router 30
wlan-gw-group 1
no shutdown
exit
exit
exit
exit
The data-path for IPv6 GRE tunneled packets, including load-balancing of tunneled packets amongst set of ISAs in the WLAN-GW group, and anchoring after tunnel decapsulation remains unchanged. Per tunnel traffic shaping is supported like IPv4 tunnels. All existing per tunnel configuration on the group-interface described in previous sections (including mobility, egress shaping, VLAN ranges, and so on) is supported identically for IPv6 tunnels. Tunnel reassembly for upstream tunneled traffic is not supported for IPv6 tunnels. TCP mss-adjust is supported for IPv6 tunnels and is configurable under wlan-gw mode on group-interface. APs must use globally routable addresses for GRE IPv6 transport. Packets with extension headers are dropped.