3Com CoreBuilder 3500, Руководство по внедрению, Страница: 68 / 592

68 C
HAPTER
4: P
HYSICAL
P
ORT
N
UMBERING
Effects of Replacing
Modules
When you remove a module, a number of changes occur, depending on
the replacement module.
Replacing Modules of
the Same Type or
Same Number of
Ports
If you remove a module that does not have any trunks or DAS ports and
replace it with another module that has the same number of ports, the
following changes occur:
■
The port numbering is not affected — 10/100 Ethernet and FDDI
modules can be exchanged without affecting the port numbers.
One Gigabit Ethernet module in any slot other than slot 4 must be
replaced by another Gigabit Ethernet module to prevent port
renumbering.
■
The system remembers ports that were members of a VLAN. When
another module is inserted into the empty slot, the ports are added
back into the VLAN.
Replacing Modules of
Different Types
More complicated changes occur when you swap six-port modules and
one-port Gigabit Ethernet modules, replace FDDI modules that have DAS
port pairs (because a DAS pair uses one bridge port to represent two
physical ports), or replace modules on which you have trunks defined
(because only the anchor port is used to define a trunk in a VLAN).
Port-Numbering Changes
Swapping six-port 10/100 Ethernet modules and FDDI modules does not
cause the system to renumber ports, but swapping six-port modules and
Gigabit Ethernet modules
does cause the system to renumber ports.
Example
If you have four 10/100 Ethernet modules, and you replace a 10/100
Ethernet module in slot 1 with a Gigabit Ethernet module, the ports are
renumbered as follows: ports 1-6 become port 1, ports 7-12 become
ports 2-7, ports 13-18 become ports 8-13, and ports 18-24 become
ports 14-19.