Brocade Multi-Service IronWare Switching Configuration Guide (Supporting R05.6.00) - Manual (Page 273)

Multi-Service IronWare Switching Configuration Guide 243
53-1003036-02
About IEEE 802.1ad
9
Layer 2 Protocol Forwarding (L2PF)
Layer 2 Protocol Forwarding (L2PF) is configured on CVLANs. You can configure the system to
forward BPDUs on all CVLANs coming at different edge ports, drop all BPDUs, or selectively enable
forwarding on a few CVLANs.
L2PF can transparently extend the STP topology of the CVLAN domain through the SVLAN domain,
as if the CVLAN switches were directly hooked together. L2PF can be applied to CVLAN, which is a
client of provider SVLAN as shown in “L2PF in a network”.
FIGURE 27 L2PF in a network
In this network, a CVLAN BPDU ingressing port P1 gets encapsulated and forwarded through the
SVLAN domain as an ordinary multicast frame and then it egresses ports P2 and P3. In the SVLAN
domain, a SVLAN BPDU originating from P4 and the ingressing port P5 gets terminated and
processed in switch S1 for STP calculation. In other words, the final STP topology in the SVLAN
domain is completely independent from the final STP topology in the CVLAN domain.
From the CVLAN domain's point of view, the physical network appears as shown in Figure 28 .