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Catalyst 3750 Metro Switch Command Reference
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Chapter 2 Catalyst 3750 Metro Switch Cisco IOS Commands
switchport trunk
switchport trunk
Use the
switchport trunk
interface configuration command to set the trunk characteristics when the
interface is in trunking mode. Use the
no
form of this command to reset a trunking characteristic to the
default.
switchport trunk
{
allowed vlan
vlan-list|
dot1q ethertype
value
|
encapsulation
{
dot1q
|
isl
|
negotiate
} |
native vlan
vlan-id
|
pruning vlan
vlan-list
}
no switchport trunk
{
allowed vlan
|
dot1q ethertype
value |
encapsulation
|
native vlan
|
{
pruning vlan
}
Syntax Description
The
vlan-list
format is
all
|
none
| [
add
|
remove
|
except
]
vlan-atom
[
,
vlan-atom...
]
where:
•
all
specifies all VLANs from 1 to 4094. This keyword is not allowed on commands that do not
permit all VLANs in the list to be set at the same time.
•
none
means an empty list. This keyword is not allowed on commands that require certain VLANs
to be set or at least one VLAN to be set.
•
add
adds the defined list of VLANs to those currently set instead of replacing the list. Valid IDs are
from 1 to 1005; extended-range VLANs (VLAN IDs greater than 1005) are valid in some cases.
allowed vlan
vlan-list
Set the list of allowed VLANs that can receive and send traffic on this
interface in tagged format when in trunking mode. See the following
vlan-list
format. The
none
keyword is not valid. The default is
all
.
dot1q ethertype
value
Sets the ethertype value on an enhanced-services (ES) port for 802.1Q
encapsulation. Used to select a nonstandard (nondefault) 2-byte ethertype to
identify 802.1Q tagged frames. The default ethertype value is 0x8100.
Note
This keyword is supported only on ES ports.
encapsulation
Set the encapsulation format on the trunk port. The default is to negotiate.
Note
Starting with release 12.2(25)EY, this keyword is not supported on
ES ports. ES ports support only 802.1Q encapsulation.
dot1q
Set the encapsulation format on the trunk port to 802.1Q. With this format,
the switch supports simultaneous tagged and untagged traffic on a port.
isl
Set the encapsulation format on the trunk port to Inter-Switch Link (ISL).
The switch encapsulates all received and sent packets with an ISL header and
filters native frames received from an ISL trunk port.
negotiate
Specify that the interface negotiate encapsulation with the neighboring
interface. This is the default. If Dynamic Inter-Switch Link (DISL) and
Dynamic Trunking Protocol (DTP) negotiation do not resolve the
encapsulation format, ISL is the selected format.
native vlan
vlan-id
Set the native VLAN for sending and receiving untagged traffic when the
interface is in 802.1Q trunking mode. The range is 1 to 4094.
pruning vlan
vlan-list
Set the list of VLANs that are eligible for VTP pruning when in trunking
mode. The
all
keyword is not valid.