ASBRs do not need to maintain inter-AS L2VPN information or reserve interfaces for inter-AS L2VPN PWs. As L2VPN information is exchanged only between PEs, this solution requires few resources and is easy to deploy.
Procedure
- Configure the capability to exchange labeled IPv4 routes.
- Perform the following steps on each PE:
Run system-view
The system view is displayed.
Run bgp as-number
The BGP view is displayed.
Run peer ipv4-address label-route-capability
The capability to exchange labeled IPv4 routes with the local ASBR is configured.
Run commit
The configuration is committed.
- Perform the following steps on each ASBR:
- Run system-view
The system view is displayed.
Run interface interface-type interface-number
The view of the interface that connects to the peer ASBR is displayed.
Run ip address ip-address { mask | mask-length }
An IP address is configured for the interface.
Run quit
Return to the system view.
Run mpls
MPLS is enabled.
Run quit
Return to the system view.
Run bgp as-number
The BGP view is displayed.
Run peer ipv4-address label-route-capability
The capability to exchange labeled IPv4 routes with the local PE is configured.
Run peer ipv4-address as-number peer-as
The peer ASBR is configured as an EBGP peer.
Run peer ipv4-address label-route-capability
The capability to exchange labeled IPv4 routes with the peer ASBR is configured.
In inter-AS BGP VPWS Option C, an inter-AS LSP must be established and the public network routes advertised between PEs and ASBRs carry MPLS labels.
An EBGP peer relationship must be established between ASBRs in different ASs for them to exchange labeled IPv4 routes.
The public network routes carrying MPLS labels are advertised through MP-BGP. According to relevant standards, label mappings about routes can be piggybacked inside the BGP Update messages that are used to advertise these routes. This feature is implemented through an extended BGP attribute, which enables BGP peers to process labeled IPv4 routes.
Run commit
The configuration is committed.
- Configure routing policies on each ASBR, so that an ASBR reallocates MPLS labels to labeled IPv4 routes to be advertised to the local PE and allocates MPLS labels to routes to be advertised to the peer ASBR.
Perform the following steps on each ASBR:
- Run system-view
The system view is displayed.
- Run route-policy policy-name1 permit node seq-number
A routing policy applicable to the local PE is created.
- Run if-match mpls-label
Filtering out labeled IPv4 routes is configured as a matching rule for the routing policy.
- Run apply mpls-label
Allocating MPLS labels to IPv4 routes is configured as an action for the routing policy.
- Run quit
Return to the system view.
- Run route-policy policy-name2 permit node seq-number
A routing policy applicable to the peer ASBR is created.
- Run apply mpls-label
Allocating MPLS labels to IPv4 routes is configured as an action for the routing policy.
- Run quit
Return to the system view.
- Run bgp as-number
The BGP view is displayed.
- Run peer ipv4-address route-policy policy-name1 export
The routing policy applicable to the local PE is applied.
- Run peer ipv4-address route-policy policy-name2 export
The routing policy applicable to the peer ASBR is applied.
- Run commit
The configuration is committed.
- Configure PEs to exchange VPWS information as BGP peers.
- Run bgp as-number
The BGP view is displayed.
- Run peer ipv4-address as-number peer-as
A BGP peer and its AS number are specified.
- Run peer ipv4-address connect-interface interface-type interface-number
The source interface for sending BGP packets is specified.
- Run l2vpn-ad-family
The L2VPN-AD address family view is displayed.
- (Optional) Run vpn-orf enable
The ORF is enabled.
- Run peer ipv4-address enable
The route exchange capability is enabled.
- Run signaling vpws or peer ip-address signaling vpws
BGP VPWS is enabled.
- Run quit
Return to the BGP view.
- Run quit
Return to the system view.
- Configure a remote BGP VPWS connection.
- Run mpls l2vpn l2vpn-name [ encapsulation { ethernet | vlan | ip-interworking | ip-layer2 } ] [ control-word | no-control-word ]
A BGP VPWS instance is created, and the MPLS-L2VPN instance view is displayed.
If heterogeneous interworking is required, specify ethernet | vlan | ip-interworking | ip-layer2 as ip-interworking for successful PW establishment.
- Run route-distinguisher route-distinguisher
An RD is configured for the L2VPN instance.
- (Optional) Run mtu mtu-value
An MTU is configured for the L2VPN instance.
The MTU size determines the maximum packet size allowed by a VPWS network. If the MTU exceeds the maximum packet size allowed by a VPWS network or an intermediate node (P), packet fragmentation or even drop will occur, affecting network transmission. The MTU is one of the VPWS negotiation parameters. If the MTUs of the same L2VPN instance on the endpoint PEs are different, the two PEs cannot exchange reachability information or establish a PW. An appropriate MTU must be set for an L2VPN instance based on the MTU of the interface bound to the L2VPN instance. Specifically, the MTU of an L2VPN instance must be less than or equal to the MTU of the interface bound to the L2VPN instance.
- (Optional) Run ignore-mtu-match
The current device is configured not to perform the MTU match check.
If the MTUs of the same L2VPN instance on the two endpoint PEs do not match, the VC cannot go Up. If some devices do not support the MTU match check, run the ignore-mtu-match command to disable this check.
- Run vpn-target { vpn-target } & <1-16> [ both | export-extcommunity | import-extcommunity ]
VPN targets are configured.
- Run ce ce-Name [ id ce-id [ range ce-range ] [ default-offset ce-offset ] ]
A CE is created in the L2VPN instance.
- Run connection [ ce-offset ce-offset-id ] interface interface-type interface-number [ tunnel-policy tunnel-policy-name ] [ raw | tagged ] [ secondary ]
A remote BGP VPWS connection is configured.
- Run commit
The configuration is committed.