Dell BigIron RX Series, Configuration Manual

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416 BigIron RX Series Configuration Guide
53-1002253-01
Ring initialization for shared interfaces
14
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.
When the RHP packet from Ring 2 reached S2, it was also forwarded from S2 to S3 on Ring 1 since
the port on S2 has a higher priority than the RHP packet. The packets is forwarded around Ring 1
until it reaches port 2/2, Ring 1’s the secondary port. The RHP packet is then blocked by that port.
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