Brocade BigIron RX Series Configuration Guide - Manual (Page 498)

420 BigIron RX Series Configuration Guide
53-1002484-04
Ring initialization for shared interfaces
14
If the port is a tunnel port, MRP checks the priority of the RHP packet and compares it to the
priority of the tunnel port:
• If the RHP packet’s priority is less than or equal to the interface’s priority, the packet is
forwarded through that interface.
• If the priority of the RHP packet is greater than the priority of the interface, the RHP packet is
dropped.
Normal flow
Figure 73 shows an example of how RHP packets are processed normally in MRP rings with shared
interfaces.
FIGURE 73 Flow of RHP packets on MRP rings with shared interfaces
Port 2/1 on Ring 1’s master node is the primary interface of the master node. The primary
interface forwards an RHP packet on the ring. Since all the interfaces on Ring 1 are regular ports,
the RHP packet is forwarded to all the interfaces until it reaches Port 2/2, the secondary interface
of the master node. Port 2/2 then blocks the packet to complete the process.
On Ring 2, Port 3/1, is the primary interface of the master node. It sends an RHP packet on the
ring. Since all ports on S4 are regular ports, the RHP packet is forwarded on those interfaces.
When the packet reaches S2, the receiving interface is a tunnel port. The port compares the
packet’s priority to its priority. Since the packet’s priority is the same as the tunnel port’s priority,
the packet is forwarded up the link shared by Rings 1 and 2.
When the RHP packet reaches the interface on node S2 shared by Rings 1 and 2, the packet is
forwarded since its priority is less than the interface’s priority. The packet continues to be
forwarded to node S1 until it reaches the tunnel port on S1. That tunnel port determines that the
RHP packet’s priority is equal to the port’s priority and forwards the packet. The RHP packet is
forwarded to the remaining interfaces on Ring 2 until it reaches port 3/2, the secondary interface
of the master node. Port 3/2 then blocks the packet to prevent a loop.
Ring 1 Ring 2
S3
S4
S1
S2
1
1
1
1
1
1
1
1
2
2
2
2 2
2
2
2
1,2
1,2
Master node
(secondary interface) port2/2
(primary interface) port2/1
Master node
port3/2 (secondary interface)
port3/1 (primary interface)
= Ring 1 RHP packet
= Ring 2 RHP packet
T
T