H3C Technologies H3C S6800 Series Switches - Manual (Page 337)

324
Figure 83 PW redundancy
The MPLS L2VPN determines whether the primary PW fails according to the LDP session status or the BFD
result. The backup PW is used when one of the following conditions exists:
• The public tunnel of the primary PW is deleted, or BFD detects that the public tunnel has failed.
• The primary PW is deleted because the LDP session between PEs goes down, or BFD detects that the
primary PW has failed.
• A manual PW switchover is performed.
Multi-segment PW
A multi-segment PW includes multiple concatenated static or LDP PWs. Creating two PWs for a
cross-connect on a PE can concatenate the two PWs. Upon receiving a packet from one PW, the PE
removes the tunnel ID and PW label of the packet, adds the PW label of the other PW, and forwards the
packet over the public tunnel. Only static and LDP PWs can form a multi-segment PW.
As shown in
Figure 84 , to create a multi-segment PW between PE 1 and PE 4, you can concatenate PW
1 and PW 2 on PE 2, and PW 2 and PW 3 on PE 3.
Figure 84 Multi-segment PW
Multi-segment PWs include intra-domain multi-segment PWs and inter-domain multi-segment PWs.
文件中找不到关系 ID 为 rId107 的图像部件。
文件中找不到关系 ID 为 rId108 的图像部件。