Netis ST3326(ST-3302) [42/118] Common port and edge port

Netis ST3326(ST-3302) [42/118] Common port and edge port
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The state of the master node represents the state of the whole RRPP ring. That is, when the
master node is in the complete (failed) state, the RRPP ring is also in the complete (failed) state.
Transit Node
All the nodes except the master node on a ring are transit nodes. A transit node can be in one of
the following states depending on the states of its primary and secondary ports:
Link-up state
When both the primary port and secondary port are up, the transit node is in the link-up state.
Link-down state
When either the primary port or the secondary port is down, the transit node is in the link-down
state.
Pre-forwarding state
When either the primary port or the secondary port is blocked, the transit node is
in the pre-forwarding state.
Edge Node and Assistant-Edge Node
In an RRPP domain, of the two nodes at which the primary ring and a subring intersect, one is the
edge node and the other is the assistant-edge node. You can configure either of them as the
edge or the assistant-edge but must ensure that the roles of the two nodes are different.
Edge nodes and assistant-edge nodes are special transit nodes. An edge or edge-assistant node
can be in one of the following three states depending on the state of its edge port:
Link-up state
When the edge port is up, the node is in the link-up state.
Link-down state
When the edge port is down, the node is in the link-down state.
Pre-forwarding state
When the edge port is blocked, the node is in the pre-forwarding state.
The state transition of an edge or edge-assistant node is the same as that of a transit node but it
is triggered by the link state change of the edge port only.
Primary Port and Secondary Port
Of the ports that connect a node to an RRPP ring, one is the primary port and the other is the
secondary port. You can configure them as needed.
The primary and secondary ports of master nodes are different in functions. A master node
sends HELLO messages out its primary port. If it can receive these HELLO messages on its
secondary port, the master node considers the RRPP ring as complete and thus blocks the
secondary port to avoid loops. If the master node fails to receive these HELLO messages within
the specified period, it considers the ring as having failed and unblocks the secondary port to
ensure service continuity.
The primary and secondary ports of a transit node are the same in functions.
In an RRPP domain, the primary ring is a logical node of each subring and it transmits subring
RRPPDUs (except the EDGE-HELLO messages) transparently as data traffic. Therefore, no data
packet or subring RRPPDU (except the EDGE-HELLO messages) can pass through a blocked port
on the primary ring.
Common Port and Edge Port
On an edge or assistant-edge node, the port connecting to the subring is called the edge port
while the two ports connecting to the primary ring are called common ports. The link between
the common port on the edge node and that on the assistant-edge node is called the common
link.
As a primary ring is considered as a logical node on its subrings, the common link is considered as
an internal link of the “primary ring” node. Thus, the common link state changes are reported
only to the master node of the primary ring.

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