MPLS Layer 2 VPN (MPLS L2VPN) Notes
MPLS Layer 2 VPN (MPLS L2VPN)
– Point-to-point
-> Any Transport over MPLS (AToM)
-> L2TPv3
– Point-to-multipoint
-> Virtual Private LAN Service (VPLS)
– Used to transport layer 2 payloads transparently
-> HDLC
-> PPP
-> ATM
-> Frame-relay
-> Ethernet
L2VPN Label
– Label exchange between PE routers
Transport Label
– Label to reach next-hop
Targeted LDP
– Multihop LDP session
-> Uses LDP router-ids to form TCP connection
– Pseudowire-id
-> 32 bit number which must match on both PE routers for a single connection
int fa0/0
-> Attachment circuit
xconnect <remote LDP router-id> <pseudowire-id> encapsulation mpls
Ethernet Configuration
R1(config)# int fa0/0
no ip add
xconnect 3.3.3.3 100 encapsulation mpls
R3(config)# int fa0/0
no ip add
xconnect 1.1.1.1 100 encapsulation mpls
sh mpls l2transport vc <id> [detail]
PPP Configuration
R1(config)# int s0/1
encap ppp
no ip add
xconnect 3.3.3.3 100 encapsulation mpls
R3(config)# int s0/1
encap ppp
no ip add
xconnect 1.1.1.1 100 encapsulation mpls
HDLC Configuration
R1(config)# int s0/1
encap hdlc
no ip add
xconnect 3.3.3.3 encapsulation mpls
R3(config)# int s0/1
encap hdlc
no ip add
xconnect 1.1.1.1 encapsultation mpls
FRoAToM
– Frame-relay over AToM
R1(config)# int s0/1
no ip add
encap frame-relay
frame-relay intf-type dce
exit
int s0/1 100 l2transport
-> 100 = DLCI
xconnect 3.3.3.3 200 encapsulation
-> 200 = pseudowire-id
R4(config)# int s0/0
encap frame-relay
ip add 10.0.0.4 255.0.0.0
frame-relay ip 10.0.0.5 100 broadcast
-> 100 = DLCI
-> broadcast (optional)
Pseudowire Class
– Set of AToM / L2TPv3 specific parameters which are applied to xconnect
pseudowire-class <name>
encapsulation { mpls | l2tpv3 }
control-word
-> Keeps properties of client and sent to the other end
-> Similar to extended communities in BGP
-> Used by some layer 2 protocols
-> Frame-relay
– FECN
– BECN
-DE-bits
-> ATM
– Cell loss priority (CLP)
int fa0/0
xconnect <ip add> <pw-id> pw-class <name>
