Configuration Guide User guide

612 FastIron Configuration Guide
53-1002494-02
Metro Ring Protocol
Figure 40 shows an example of an MRP metro ring.
FIGURE 40 Metro ring – normal state
The ring in this example consists of four MRP nodes (Brocade switches). Each node has two
interfaces with the ring. Each node also is connected to a separate customer network. The nodes
forward Layer 2 traffic to and from the customer networks through the ring. The ring interfaces are
all in one port-based VLAN. Each customer interface can be in the same VLAN as the ring or in a
separate VLAN.
One node is configured as the master node of the MRP ring. One of the two interfaces on the
master node is configured as the primary interface; the other is the secondary interface. The
primary interface originates Ring Health Packets (RHPs), which are used to monitor the health of
the ring. An RHP is forwarded on the ring to the next interface until it reaches the secondary
interface of the master node. The secondary interface blocks the packet to prevent a Layer 2 loops.
F
FF
Customer A
Switch B
Customer A
Customer A
Customer A
Switch A
Switch C
Switch D
Master
Node
B
F
F
F
F
F
F
F
F
This interface blocks
Layer 2 traffic
to prevent a loop