Figure 118: Access Dual-Homing For Pbb Eline - Beb Failure - Alcatel-Lucent 7750 SR Manual

PBB Features
associated with the active MC-LAG are actively used for forwarding into B-VPLS the traffic
ingressing related EPIPE SAPs.
MC-LAG protocol keeps track of which side is active and which is standby for a given MC-LAG
grouping and activates the standby link in a failure scenario. The source BMACs C1 and A1 are
used for PBB encapsulation as traffic arrives at the EPIPE SAPs on P11 and P9, respectively.
MAC Learning in the B-VPLS instances installs MAC FIB entries in BEB C and BEB A as
depicted in
between BEB A and BEB C.
Active link (P11) or access node (BEB C) failures are activating through MC-LAG protocol, the
standby link (P12) participating in the MC-LAG on the pair MC-LAG device (BEB D). The
failure of BEB C is depicted in
CFM Message - New Opcode
Sorce: CC1 Dest: CFM-Mcast
Bridge Table on
BEB D
BMAC A1 EP8
EP8
BEB
D
P12
BMAC
Active
C1
Bridge Table on
BEB C
BMAC A1
The following process steps apply:
•
•
Page 804
Figure 117. The highlighted Ethernet tunnel (EPS) will be used to forward the traffic
BCB-E
EP7 IP6 EP5
BMAC BMAC
D
MC-LAG
P11
Standby
ES1
EP6
C-MAC-1

Figure 118: Access Dual-Homing for PBB ELINE - BEB Failure

BEB D will lose MC-LAG communication with its peer BEB C - no more keep-alives
from BEB C or next-hop tracking may kick in.
BEB D assumes BEB C is down and activates all shared MC-LAG links, including P12.
Figure 118. The same procedure applies for the link failure case.
BCB-F
EP4 EP3
BMAC
BEB BEB
C
C B
P10
BMAC BMAC
Standby
C1 A1
BVPLS Instance
EPIPE Instance
EPS Tunnel
Bridge Table on
BEB A
BMAC
EP2 EP1
BMAC
B A
MC-LAG
P9
Active
Bridge Table on
ES2
BEB B
BMAC C1 EP4
C-MAC-2
7750 SR OS Services Guide
C1 EP2
BEB
A
BMAC
A1
OSSG354