关于DTP模式的问题？

ccnafasttrack

在关于DTP知识当中，有这么一个命令：switchport negotiate，老师在讲的时候说这条命令的意思是不允许协商，而如果是no switchport negotiate则是允许协商，关于这个不太理解。应该反过来说是不是更合理

michael_kui

在接口下是敲no  Nonegotiate

ccnafasttrack

ccnafasttrack

看错了，是nonegotiate,大家不要笑话我

wells_1188

你没懂的意思，你想问的是什么？

Rockyw

ccnafasttrack 发表于 2016-4-18 09:09
看错了，是nonegotiate,大家不要笑话我

那现在应该理解了吧

ccnafasttrack

Rockyw 发表于 2016-4-18 09:41
那现在应该理解了吧

恩恩，理解了，但是呢？为什么我的GNS3的Cisco IOS Software, 3600 Software (C3660-IK9O3S-M), Version 12.4(13b), RELEASE SOFTWARE (fc3)这个版本的IOS不支持这条命令：switchport mode dynamic auto/desirable，dynamic根本敲不出来？这是怎么回事？
这是Version信息：
ESW1#show version
Cisco IOS Software, 3600 Software (C3660-IK9O3S-M), Version 12.4(13b), RELEASE SOFTWARE (fc3)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2007 by Cisco Systems, Inc.
Compiled Tue 24-Apr-07 21:18 by prod_rel_team

ROM: ROMMON Emulation Microcode
ROM: 3600 Software (C3660-IK9O3S-M), Version 12.4(13b), RELEASE SOFTWARE (fc3)

ESW1 uptime is 8 minutes
System returned to ROM by unknown reload cause - suspect boot_data[BOOT_COUNT] 0x0, BOOT_COUNT 0, BOOTDATA 19
System image file is "tftp://255.255.255.255/unknown"


This product contains cryptographic features and is subject to United
States and local country laws governing import, export, transfer and
use. Delivery of Cisco cryptographic products does not imply
third-party authority to import, export, distribute or use encryption.
Importers, exporters, distributors and users are responsible for
compliance with U.S. and local country laws. By using this product you
agree to comply with applicable laws and regulations. If you are unable
to comply with U.S. and local laws, return this product immediately.
--More--

sboku

Rockyw 发表于 2016-4-18 10:41
那现在应该理解了吧

ccnafasttrack

michael_kui 发表于 2016-4-18 17:39
在接口下是敲no  Nonegotiate

在接口上敲这个命令还是没有啊！

ccnafasttrack

sboku 发表于 2016-4-18 10:20

帮我看看上面的问题呗，难道是IOS的问题吗？

Rockyw

ccnafasttrack 发表于 2016-4-18 20:00
帮我看看上面的问题呗，难道是IOS的问题吗？

换一个高一点的版本看看

michael_kui

ccnafasttrack 发表于 2016-4-18 19:59
在接口上敲这个命令还是没有啊！

IOS版本问题，这个敲不敲都可以，做项目建议敲上。

sboku

ccnafasttrack 发表于 2016-4-18 21:00
帮我看看上面的问题呗，难道是IOS的问题吗？

IOS太旧了。nonegotiation要在SW的12.2（53）SE2版本以上才能使用。12.2（53）SE2是在2010年出版的。你用的Cisco3600的12.4（13b）是在2008年以前出版的，所以没法用。

Catalyst 3750-X and 3560-X Switch Command Reference, Release 15.2(1)E and Later
http://www.cisco.com/c/en/us/td/ ... /CR_3750X/cli3.html

Release Notes for Catalyst 3750-X and 3560-X Switches, Cisco IOS Release 12.2(53)SE2
http://www.cisco.com/c/en/us/td/ ... /notes/OL19594.html


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switchport nonegotiate

Use the switchport nonegotiate interface configuration command on the switch stack or on a standalone switch 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 learn the trunking status.

Command Modes

Interface configuration

Command History
--------------------------------
Release             Modification
--------------------------------
12.2(53)SE2    This command was introduced.
--------------------------------

------------------------------------------------------------------------------------------------

ccnafasttrack

sboku 发表于 2016-4-19 00:20
IOS太旧了。nonegotiation要在SW的12.2（53）SE2版本以上才能使用。12.2（53）SE2是在2010年出版的。你用 ...

那no nonegotiate敲不了，那switchport nonegotiate是什么怎么回事？也敲不了啊。关于IOS的版本好乱啊感觉，12.4应该也是比较新的了

sboku

ccnafasttrack 发表于 2016-4-19 10:49
那no nonegotiate敲不了，那switchport nonegotiate是什么怎么回事？也敲不了啊。关于IOS的版本好乱啊感 ...

路由器的IOS和SW的IOS，不是一个系列，所以不能用数字的大小来判断。12.4是差不多十年前的，很老的了。

http://www.cisco.com/c/en/us/td/ ... /CR_3750X/cli3.html

switchport nonegotiate

Use the switchport nonegotiate interface configuration command on the switch stack or on a standalone switch 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 learn the trunking status.

Command Modes

Interface configuration

Command History
Release
        
Modification

12.2(53)SE2
        

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 a ccess 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 to refrain from negotiating trunking mode and to act as a trunk or access port (depending on the mode set):
Switch(config)# interface gigabitethernet2/0/1
Switch(config-if)# switchport nonegotiate