switchport mode dynamic desirable

Unanswered Question
Mar 26th, 2009
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Are there any pitfalls of having this command on interfaces that will never be used for trunks? i.e. any unneeded traffic etc.


Thanks in advance.


/rls

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Edison Ortiz Thu, 03/26/2009 - 08:28
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They can actually become trunking interfaces if connected to another switch with mode desirable or mode auto


If you don't want to ever have those interfaces in trunking mode, change it to mode access


HTH,


__


Edison.

rsamuel708 Thu, 03/26/2009 - 08:35
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The majority of our switch interfaces are configured as such:


interface FastEthernet1/0/6

switchport access vlan 120

switchport mode dynamic desirable

duplex full

speed 100

spanning-tree portfast


...so in this case, I should just be removing the 'switchport mode dynamic desirable' line, correct?


/rls

Edison Ortiz Thu, 03/26/2009 - 08:39
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Removing the line won't fix the problem.


The switchport needs to have a mode to run on. It depends on the hardware but removing the line may set your switchport to dynamic auto. If you are connecting to hosts, the recommended macro to run is switchport host


http://www.cisco.com/en/US/docs/switches/lan/catalyst3560/software/release/12.2_46_se/command/reference/cli3.html#wp1948119




HTH,



rsamuel708 Thu, 03/26/2009 - 08:48
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So just to be clear, the 'switchport host' command will replace the other command in the configuration once I enter it in config mode?


/rls

Edison Ortiz Thu, 03/26/2009 - 10:24
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switchport host is a macro. The command is clearly explained on the link I posted. If the commands that are part of the macro are already under the switchport, they won't be removed. It's like a copy and paste of a template that you may have.



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