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Catalyst 6500 Series Switch Command Reference—Release8.4
OL-6244-01
Chapter2 Catalyst 6500 Series Switch and ROM Monitor Commands set trunk
set trunk
To configure trunk ports and to add VLANs to the allowed VLAN list for existing trunks, use the set
trunk command.
set trunk mod/ports {on | off | desirable | auto | nonegotiate} [vlans | none]
[isl | dot1q | dot10 | lane | negotiate]
set trunk all off
Syntax Description
Defaults The default port mode is auto.
Command Types Switch command.
Command Modes Privileged.
Usage Guidelines This command is not supported by the NAM.
mod/port Number of the module and the port or ports on t he m od ule.
on Forces the port to become a trunk port and persuade the neighborin g po rt to bec om e a
trunk port. The port becomes a trunk port even if the neighboring port does no t a gre e
to become a trunk.
off Forces the port to become a nontrunk port and persuade the neig hboring port to become
a nontrunk port. The port becomes a nontrunk port even if the neighboring port does no t
agree to become a nontrunk port.
desirable Causes the port to negotiate actively with the neighboring port to be co me a tr unk li nk.
auto Causes the port to become a trunk port if the neighboring port tries to negotiate a trunk
link.
nonegotiate Forces the port to become a trunk port but prevents it from sending DTP frames to its
neighbor.
vlans (Optional) VLANs to add to the list of allowed VLANs on the trunk; valid values are
from 1 to 4094.
none (Optional) Clears all VLANs from the trunk. See the “Usage Guidelines” section for
more information.
isl (Optional) Specifies an ISL trunk on a Fast or Gigabit Ethernet port.
dot1q (Optional) Specifies an IEEE 802.1Q trunk on a Fast or Gigabit Ethe rn et por t.
dot10 (Optional) Specifies an IEEE 802.10 trunk on a FDDI or CDDI po rt.
lane (Optional) Specifies an ATM LANE trunk on an ATM port.
negotiate (Optional) Specifies that the port become an ISL (preferred) or 802.1Q trunk,
depending on the configuration and capabilities of the neighboring port.
all off Turns off trunking on all ports.