Terminology - HP ProCurve 5300xl Series Management Manual

Terminology

Term
downlink port
(downstream port)
edge switch
interior switch
single-instance spanning A single spanning-tree ensuring that there are no logical network loops associated with any
tree
uplink port
(upstream port)
wiring closet switch
Port 3
4
Switch
(4108-Edge)
Port 5
Figure 6-13. Example of an Edge Switch in a Topology Configured for STP Fast Uplink
Definition
A switch port that is linked to a port on another switch (or to an end node) that is sequentially
further away from the STP root device. For example, port "C" in figure 6-12, above, is a
downlink port.
For the purposes of fast-uplink STP, this is a switch that has no other switches connected to
its downlink ports. An edge switch is sequentially further from the root device than other
switches to which it is connected. Also termed wiring closet switch or leaf switch. For
example, switch "4" in figure 6-13 (page 6-31) is an edge switch.
In an STP environment, a switch that is sequentially closer to the STP root device than one
or more other switches to which it is connected. For example, switches "1", "2", and "3" in
figure 6-13 (page 6-31) are interior switches.
of the connections to the switch, regardless of whether there are any VLANs configured on
the switch. For more information, see "Spanning Tree Protocol (STP)" in chapter 9,
"Configuring Advanced Features", in the Management and Configuration Guide for your
switch.
A switch port linked to a port on another switch that is sequentially closer to the STP root
device. For example, ports "A" and "B" in figure 6-12 on page 6-30 are uplink ports.
Another term for an "edge" or "leaf" switch.
When single-instance spanning tree (STP) is running in a network and a
forwarding port goes down, a blocked port typically requires a period of
(2 x (forward delay) + link down detection)
to transition to forwarding. In a normal spanning tree environment, this
transition is usually 30 seconds (with the
default of 15 seconds). However, by using the fast-uplink spanning tree
feature, a port on a switch used as an edge switch can make this transition in
as little as ten seconds. (In an STP environment, an edge switch is a switch
that is connected only to switches that are closer to the STP root switch than
the edge switch itself, as shown by switch "4" in figure 6-13, below.)
2
Switch
6
3
Switch
1
Forward Delay
1
Switch
(Root)
8
Spanning-Tree Operation
802.1D Spanning-Tree Protocol (STP)
parameter set to its
LAN
Link blocked by STP:
6-31