Dell FCX624-E Laptop User Manual


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PowerConnect B-Series FCX Configuration Guide 389
53-1002266-01
Protected link groups
11
About active ports
When you create a protected link group, you can optionally specify which port in the protected link
group is the active port. If you do not explicitly configure an active port, the Dell PowerConnect
device dynamically assigns one. A dynamic active port is the first port in the protected link group
that comes up (usually the lowest numbered port in the group).
Static and dynamic active ports operate as follows:
A static active port (an active port that you explicitly configured) pre-empts other ports in the
protected link group. So, if a static active link comes back up after a failure, the Dell
PowerConnect device will revert to this link as the active link.
A dynamic active port (an active port assigned by the software) is non-pre-emptive. Therefore,
if a dynamic active link comes back up after a failure, the Dell PowerConnect device does not
revert to this link, but continues carrying traffic on the current active link.
Using UDLD with protected link groups
You can use UDLD with protected link groups to detect uni-directional link failures and to improve
the speed at which the device detects a failure in the link.
NOTE
When UDLD and protected links are configured on a port and the link goes down, protected links will
not come up after UDLD becomes “healthy” again without first physically disabling then re-enabling
the link.
Configuration notes
You can configure a maximum of 32 protected link groups.
There is no restriction on the number of ports in a protected link group.
Each port can belong to one protected link group at a time.
PowerConnect B-Series FCX Series devices support protected link groups consisting of Gbps
fiber ports, 10/100/1000 copper ports, and 10/100 ports, or any combination thereof. These
devices do not support protected link groups on 10-GbE ports.
This feature is supported with tagged and untaggedports.
This feature is supported with trunk ports.
The protected link groups feature is not supported with LACP.
There is no restriction on the properties of ports in a protected link group. For example,
member ports can be in the same VLAN or in different VLANs.
When two switches are connected together with links in a protected link group, and the ports
connecting the switches together are part of a protected link group, you must configure two
connecting ports (one port on each switch) as active ports of the protected link group. The
following example illustrates this scenario.