User's Manual

297
Users Manual of CS-6306R
After the master node receives the link-down packet, its state will be changed to the Failed state and at the
same time the secondary port will be opened, the FDB table will be refreshed, and the
RING-DOWN-FLUSH-FDB packets will be transmitted from two ports for notifying all nodes. As shown in the
following figure, the master node on the major ring notifies the transit node on the major ring of refreshing
FDB; sub ring 1 has troubles on its channel, so the edge port of the assistant node will be blocked; the master
node of sub ring 2 notifies the transit nodes on the sub ring to refresh FDB and then the transparent
transmission will be conducted on the major ring.
Figure 13: Ring transmitting troubles and refreshing FDB
27.3.2.2 Recovery
When the port on the transit node is recovered, the transit node will shift to its Preforwarding state. The
processing procedure when the port of the transit node is recovered is shown in the following figure. The link
of the major ring will recover, while the transit node, which connects the link of the major ring, changes into the
Preforwarding state, blocks the data packets but allows the Hello packets of the control packet to pass
through; similarly, the transit node on sub ring 2 also changes into the Preforwarding state; when the hello
packet on sub ring 1 arrives the edge node, due to the fact that the resumed transit node only allows the
control packet of the major to pass through and that the hell packet of sub ring 1 is just like the data packet of
the major ring, the hello packet cannot be forwarded.
Figure 14: Recovery of the ring’s link and the shift of the transit node to preforwarding