BigIron RX Series Configuration Guide 401
53-1002253-01
Chapter
14
Metro Ring Protocol (MRP) Phase 1 and 2
Metro Ring Protocol (MRP) phase 1
MRP Phase 1 is a Brocade proprietary protocol that prevents Layer 2 loops and provides fast
reconvergence in Layer 2 ring topologies. It is an alternative to STP and is especially useful in
Metropolitan Area Networks (MANs) where using STP has the following drawbacks:
• STP allows a maximum of seven nodes. Metro rings can easily contain more nodes than this.
• STP has a slow reconvergence time, taking many seconds or even minutes. MRP can detect
and heal a break in the ring in sub-second time.
Figure 63 shows an MRP metro ring.
FIGURE 63 Metro ring – normal state
F
FF
Customer A
Member
Node
Switch B
Customer A
Customer A
Customer A
Switch A
Switch C
Switch D
Member
Node
Member
Node
Master
Node
B
F
F
F
F
F
F
F
F
This interface blocks
Layer 2 traffic
to prevent a loop