FUJITSU PSWITCH
User’s Guide
76
December/2018
whether we receive those sent LDFs. If a loop is detected on a physical port or LAG
interface, it means a LDF which was sent from the switch is received by itself; some
port(s) will be blocked to cut the detected loop for a period of time, and recovery to
normal when loop cases disappear.
To enhance the loop protection efficiency, we will reserve a dedicated buffer queue
to handle LDF packets. This feature can ensure that our mechanism can work in
extreme network environment.
3.1.2.10.
Link Dependency (Link down relay and Backup port)
Link dependency allows the link status of specified ports to be dependent on the
link status of other ports. Consequently, if a port that is depended on by other ports
loses link, the dependent ports are inactive (Link Down Relay) or active (Backup
Port) so that the dependent ports links are brought down or up respectively.
User can form a link dependency group by upstream, downstream, and group
action. Upstream/Downstream is a group of interfaces, the interface could be a
physical port or a port-channel.
When group action is DOWN (Link Down Relay), behavior of upstream/downstream
will like below:
When all upstream ports link down, downstream ports will become inactive
-
When one of upstream port link up, downstream ports will become active
-
When group action is UP (Backup Port), behavior of upstream/downstream will like
below:
When all upstream ports link down, downstream ports will become active
-
When one of upstream port link up, downstream ports will become inactive
-
Active/inactive is different from admin enabled/disabled. If a port is admin enabled,
an inactive setting will cause the port link down. If one port is admin disabled,
whether active or inactive setting cannot change the link status. Group status can
control the link dependency work or not. If some ports link down or link up by link
dependency rules, disable the group will recover the port status to original.
Link dependency has a few limitations:
This function is provided in normal mode only. (not in EHM mode)
Upstream/Downstream supports physical port and port-channel, but not
port-channel member.
Each port (physical port/ port-channel) can only participate in one group, and it
cannot exist in both upstream and downstream at the same time
