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Cisco 10000 Series Router Software Configuration Guide
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Chapter 21 Configuring L2VPN Interworking
Routed Interworking
Ethernet to VLAN over LS—Bridged: Example
Ethernet to VLAN over AToM—Bridged: Example
Routed Interworking
Routed interworking is used to carry Layer 3 packets. Each protocol type has a different routed
interworking function. The most common routed interworking function is support for Internet Protocol
(IP). Therefore, this type of interworking function is also called IP Interworking, and a new type of
pseudowire, IP over MPLS, is used.
In routed interworking, IP packets that are extracted from the attachment circuits are sent over the
pseudowire. The pseudowire works in the IP Layer 2 transport (VC type 0x000B) like-to-like mode. The
interworking function at NSP performs the required adaptation based on the attachment circuit
technology. Non-IPv4 packets are dropped.
In routed interworking, the following considerations are to be kept in mind:
•
Address resolution packets (ARP), inverse ARP, and IPCP are punted to routing protocol. Therefore,
NSP at the PE router must provide the following functionality for address resolution:
–
Ethernet—PE device acts as a proxy-ARP server to all ARP requests from the CE router. The
PE router responds with MAC address of its local interface.
PE
config t
interface atm 2/0/0
pvc 0/200 l2transport
encapsulation aal5snap
interface gigabitethernet 5/1/0
no ip address
connect ETH-VLAN gigabitethernet 5/0/0 gigabitethernet 5/1/0.3
interworking ethernet
PE1
PE2
ip cef
!
mpls label protocol ldp
mpls ldp router-id Loopback0 force
!
pseudowire-class atom
encapsulation mpls
!
interface Loopback0
ip address 10.9.9.9 255.255.255.255
!
interface FastEthernet0/0
no ip address
!
interface FastEthernet1/0
xconnect 10.9.9.9 123 pw-class atom
ip cef
!
mpls label protocol ldp
mpls ldp router-id Loopback0 force
!
pseudowire-class atom-eth-iw
encapsulation mpls
interworking ethernet
!
interface Loopback0
ip address 10.8.8.8 255.255.255.255
!
interface FastEthernet1/0.1
encapsulation dot1q 100
xconnect 10.9.9.9 123 pw-class atom-eth-iw