4-34
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Resilient Links are available over twisted pair media
(10BASE-T) because it carries a link test pulse which is
used to decide whether the main link has failed and
the standby link should take over. However, there is
no such link signal over coaxial media (10BASE-2), so
you cannot set up resilient links using the hub’s
10BASE-2 (Coax) port.
If you have more than two hubs there are a number
of ways you can use resilience when linking them.
Remember to follow hub connection requirements;
always connect an MDIX port to an MDI port, setting
the MDIX switch as appropriate, see
“Connecting
Hubs Using 10BASE-T” on page 2-10
.
When your network is in use, the hub that has been
used to set up the resilient link pair, monitors the
state of both the main link and the standby link. If
the main link fails, the standby link becomes active. If
the fault with the main link is solved, the standby link
stays active and the main link acts like a standby link.
You can use management to view the status of your
links, and to send
traps
(messages) to an IP/IPX-based
network management application, if anything
changes.
Setting Up a Resilient Link Pair
To set up a resilient link pair, you need to manage
the hub that both links in the pair are connected to.
You can set up to 4 resilient link pairs for the hub.
When you set up your resilient link pair, you only
need to specify the ports that the main link and
standby link are connected to.
Resilient Link Rules
Always follow these rules when setting up a resilient
link pair:
■
Configure the resilient link pair at only one end of
the link. In other words, only one hub controls each
resilient link pair you set up.
■
Each resilient link pair can only have one main link
and one standby link.
■
Each link must not belong to more than one resilient
link pair.
■
For a port that is part of a resilient link pair:
■
Do not disable the link pulse generation.
■
Do not enable security for the port.
16710.bk : MANAGING.FRM Page 34 Tuesday, October 7, 1997 11:38 AM
