From: Dennis J. Hartmann (dennisjhartmann@hotmail.com)
Date: Wed Apr 20 2005 - 14:34:16 GMT-3
You can not specify switchport trunk encapsulation dot1q, until
specifying sw mode trunk. Even after specifying both commands, if you type
in the show interface fast 0/x switchport, the interface is still sending
out DTP frames. Since the encapsulation is locked down, the dtp frames are
probably not doing anything, but they're still being sent out.
-DH
switchport nonegotiate
Use the switchport nonegotiate interface configuration command to specify
that Dynamic Trunking Protocol (DTP) negotiation packets are not sent on the
Layer 2 interface. The switch does not engage in DTP negotiation on this
interface. Use the no form of this command to return to the default setting.
switchport nonegotiate
no switchport nonegotiate
Syntax Description
This command has no arguments or keywords.
Defaults
The default is to use DTP negotiation to determine trunking status.
Command Modes
Interface configuration
Command History
Release
Modification
12.1(4)EA1
This command was introduced.
Usage Guidelines
The no form of the switchport nonegotiate command removes nonegotiate
status.
This command is valid only when the interface switchport mode is access or
trunk (configured by using the switchport mode access or the switchport mode
trunk interface configuration command). This command returns an error if you
attempt to execute it in dynamic (auto or desirable) mode.
Internetworking devices that do not support DTP might forward DTP frames
improperly and cause misconfigurations. To avoid this, you should turn off
DTP by using the switchport no negotiate command to configure the interfaces
connected to devices that do not support DTP to not forward DTP frames.
When you enter the switchport nonegotiate command, DTP negotiation packets
are not sent on the interface. The device does or does not trunk according
to the mode parameter: access or trunk.
If you do not intend to trunk across those links, use the switchport mode
access interface configuration command to disable trunking.
To enable trunking on a device that does not support DTP, use the
switchport mode trunk and switchport nonegotiate interface configuration
commands to cause the interface to become a trunk but to not generate DTP
frames.
Examples
This example shows how to cause a port interface to refrain from negotiating
trunking mode and to act as a trunk or access port (depending on the mode
set):
Switch(config-if)# switchport nonegotiate
You can verify your setting by entering the show interfaces interface-id
switchport privileged EXEC command.
Related Commands
Command
Description
show interfaces switchport
Displays the administrative and operational status of a switching
(nonrouting) port, including port blocking and port protection settings.
switchport mode
Configures the VLAN membership mode of a port.
Sincerely,
Dennis J. Hartmann
White Pine Communications
dh8@pobox.com /
CCSI#23402/CCIP/CCNP/CCDP/CCNA/CCDA
Cisco IP Voice Support & Design Specialist
Cisco Optical, VPN & IDS Specialist
MCSE
-----Original Message-----
From: Ken Bartlinski [mailto:kenbar3@gmail.com]
Sent: Wednesday, April 20, 2005 1:28 PM
To: 'Dennis J. Hartmann'; ccielab@groupstudy.com
Subject: RE: Switchport nonegotiate / DTP
Dennis,
You do not have to turn off DTP. You just use the "switchport trunk
encapsulation dot1q" command on the port in question to achieve this goal.
If you further wish to force the port to only trunk, turn off DTP using the
"switchport mode trunk" command.
Ken
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
Dennis J. Hartmann
Sent: Wednesday, April 20, 2005 12:14 PM
To: ccielab@groupstudy.com
Subject: Switchport nonegotiate / DTP
If I'm required to statically set all trunk ports to dot1q, I'll be
turning off DTP with the switchport nonegotiate command.
I didn't notice this in the NMC solutions. Any ideas?
Sincerely,
Dennis J. Hartmann
White Pine Communications
CCSI#23402/CCIP/CCNP/CCDP/CCNA/CCDA
Cisco IP Voice Support & Design Specialist
Cisco Optical, VPN & IDS Specialist
MCSE
This archive was generated by hypermail 2.1.4 : Tue May 03 2005 - 07:55:04 GMT-3