User's Manual

283
Users Manual of CS-6306R
27.1.2.14 Complete Flag of Ring
Both the master node and the transit node can show whether the current ring network is complete through the
state symbol “COMPLETE”. On the master node, only when all links of the ring network are normal, the
primary port is in forwarding state and the secondary port is in blocking state can the "COMPLETE” symbol be
real; on the transit node, only when its two transit ports are in forwarding state can the “COMPLETE” symbol
be true.
The state symbol of the ring network helps user to judge the topology state of the current network.
27.1.3 Types of EAPS Packets
The EAPS packets can be classified into the following types, as shown in table 1.1.
Table 1.1 Types of EAPS packets
Type of the packet Remarks
HEALTH It is transmitted by the master node to detect whether the topology
of the ring network is complete.
LINK-DOWN Indicates that link interruption happens in the ring. This kinds of
packets are transmitted by the transit node.
RING-DOWN-FLUSH-FDB It is transmitted by the master node after interruption of the ring
network is detected and the packets show the MAC address aging
table of the transit node.
RING-UP-FLUSH-FDB It is transmitted by the master node after interruption of the ring
network is resumed and the packets show the MAC address aging
table of the transit node.
EDGE-HELLO It is decided by the edge port of the edge node, transmitted by the
main-ring port that the edge node corresponds to, and detects
whether the major ring is complete.
27.1.4 Fast Ethernet Ring Protection Mechanism
27.1.4.1 Polling mechanism
The primary port transmits the HEALTH packets to the control VLAN. In normal case, the HEALTH packets
will pass through all other nodes of the ring and finally arrive at the secondary port of the master node.
The secondary port blocks all data VLANs in primitive condition. When receiving the HEALTH packets
continuously, the secondary port keeps blocking data VLANs and blocking the loop. If the secondary port
does not receive the HEALTH packets from the primary port in a certain time (which can be configured), it will
regard the ring network is out of effect. Then the master node removes the blocking of data VLANs on the
secondary port, ages the local MAC address table, and transmits the RING-DOWN-FLUSH-FDB packets to
notify other nodes.
If the master node receives the HEALTH packets at the secondary port that is open to data VLANs, the ring
network is resumed. In this case, the master node immediately blocks data VLANs on the secondary port,
updates the local topology information and reports other nodes to age the MAC address table through