Stackable NWay Ethernet Switch User’s Guide
Using the Console Interface 55
Figure 6-13. Configure Advanced Switch Features screen
The fields you can set are:
♦
Port Auto-Partition Capability on All Ports
When this function is enabled, if too many consecutive
collisions occur on an individual port, the port will be blocked off until a good packet is seen on the wire. If
a port is partitioned, the Switch can only transmit data, not receive it.
♦
Head Of Line (HOL) Blocking Prevention Enables
or
disables
Head-Of-Line Blocking Prevention.
Head-of Line blocking occurs when a packet originating on Port 1, for instance, needs to be forwarded to
Ports 2 and 3. If Port 2 is occupied (causing the packet to be held in memory until the port is free), the
packet destined for Port 3 will also be delayed, even though the port may be free. Cumulatively, these
delays can have a noticeable effect on overall network performance. Enabling HOL Blocking Prevention
prevents Head-of-Line blocking from occurring, meaning that the packet destined for Port 3 gets delivered
immediately.
Configure Port
The port configuration screen allows you to change the port state in the case when you would like to partition
a port due to excessive collision, or for observation, device repair, or security reasons. Great caution, however,
must be observed when partitioning a port; you should make sure that the partitioned port is not being used
as the port to control or monitor the condition of other devices.
