User's Manual

282
Users Manual of CS-6306R
A port can be set as the primary port or the transit port of a node and it cannot be reset.
27.1.2.12 Common Port and Edge Port
The edge node and the assistant node are the places where the sub ring and the major ring intersect. As to
the two ports that access the Ethernet, one is a common port, which is the public port of the sub ring and the
major ring; the other is the edge port in the sub ring. The roles of the two ports are decided by users through
configuration.
The common port is on the main-ring port and so its state is decided by the state of the main-ring port. The
common port itself has no operations or notifications. When the link, connecting the common port, changes,
the sub-ring node where the common port lies will not be notified. The existence of the common port just
guarantees the completeness of the ring.
The edge port of the edge node is in forwarding or preforwarding state when it is up. Its basic characteristics
are consistent with those of the transit port except one function. The exceptional function is that when the
edge port is up and its corresponding main-ring port is also up, it will transmit the edge-hello packets from the
main-ring port to detect the completeness of the major ring.
The edge port of the assistant node is in forwarding, pre-forwarding or EdgePreforwarding state when it is up.
Besides the same characteristics of the transit port, it also has one more state, the EdgePreforwarding state.
If the edge port is in forwarding state and the main-ring port that the edge port corresponds to has not
received the edge-hello packets, the state of the edge port is changed into the EdgePreforwarding state, and
it only receives and forwards the control packets and blocks the data VLAN until the corresponding main-ring
port receives the Edge-hello packets again.
The edge port of the edge node and the assistant node is to help detect the completeness of the major ring.
For more details, see the channel status checkup mechanism of the sub-ring protocol packets on the major
ring in the following chapter.
Remarks:
Each port can be set as the only edge port of a node and it cannot be configured again; the common port can
be borne only on a port of the major ring and it cannot be configured on a port without a corresponding
main-ring port.
27.1.2.13 FLUSH MAC FDB
The Ethernet ring protection protocol can transmit data packets to the correct link by controlling the aging of
the switch’s MAC address table when the topology changes. In general, the time for a MAC address to age in
the MAC address table is 300 seconds. The ring protection protocol can control the aging of the MAC address
table in a short time.