UP/DOWN Status

Unanswered Question
Nov 16th, 2007

What are the usual issues when an interface (ethernet) is in an UP/DOWN status . DOWN = Protocol. Would it show this status if nothing was plugged in to the ethernet port..


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bvsnarayana03 Fri, 11/16/2007 - 07:44

If it is "ethernet down, line protocol down", then a physical layer problem like cable not connected.

If only protocol is down, then check if this interface on other connecting device is UP, duplex & speed is matching, encapsulation on both ends is same.

Pls rate if helped.

Richard Burts Fri, 11/16/2007 - 07:50


Your response is quite appropriate for a back to back serial connection. But not so much for an Ethernet, which I believe was the focus of the original post.


For an Ethernet to be up/down could be caused by having nothing plugged into the Ethernet interface, or from a speed mismatch on the connection.



Wilson Samuel Fri, 11/16/2007 - 08:29


Just one small point, the above holds true for the Routers (and the HWIC LAN Cards on a router) however if its a catalyst switch the chances are that it will show an "Error-Disabled Stat"

You may refer the following URL for further info:



Wilson Samuel

PS: Please rate all helpful posts


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