Comments on: UDLD – To Global or Per Port http://etherealmind.com/udld-to-global-or-per-port/ Network design, architecture, thinking, working. Tech. Wed, 23 May 2012 23:00:00 +0000 hourly 1 http://wordpress.org/?v=3.3.2 By: Rob http://etherealmind.com/udld-to-global-or-per-port/#comment-116 Rob Mon, 29 Nov 2010 17:59:21 +0000 http://etherealmind.com/2008/02/03/udld-to-global-or-per-port/#comment-116 Even if you enable aggressive the ports will still function as UDLD must first see the link as bidirectional before taking it down. It will flag the status as 'unknown'. Although I would suggest this will cause you confusion and so should be avoided. Even if you enable aggressive the ports will still function as UDLD must first see the link as bidirectional before taking it down. It will flag the status as ‘unknown’. Although I would suggest this will cause you confusion and so should be avoided.

]]> By: chris http://etherealmind.com/udld-to-global-or-per-port/#comment-115 chris Sat, 06 Feb 2010 14:35:49 +0000 http://etherealmind.com/2008/02/03/udld-to-global-or-per-port/#comment-115 Even aggressive mode is okay on only one side, isn't it? My understanding is that UDLD only reacts to LOSS of a peer. If a UDLD-supporting peer device is never detected in the first place, then no action will be taken. The UDLD neighbor info just stays in "undetermined" state (or somesuch). Also, regarding copper ports, there are a couple of other factors that contribute to it not making sense there: 1) copper ports are kept alive by Ethernet Link Pulse signaling anyway, making UDLD unnecessary. 2) copper ports might be connected to a hub where some devices support UDLD, and others don't. Things could get ugly fast. Even aggressive mode is okay on only one side, isn’t it?

My understanding is that UDLD only reacts to LOSS of a peer. If a UDLD-supporting peer device is never detected in the first place, then no action will be taken. The UDLD neighbor info just stays in “undetermined” state (or somesuch).

Also, regarding copper ports, there are a couple of other factors that contribute to it not making sense there:
1) copper ports are kept alive by Ethernet Link Pulse signaling anyway, making UDLD unnecessary.
2) copper ports might be connected to a hub where some devices support UDLD, and others don’t. Things could get ugly fast.

]]> By: Tassos http://etherealmind.com/udld-to-global-or-per-port/#comment-114 Tassos Sun, 24 Feb 2008 12:42:14 +0000 http://etherealmind.com/2008/02/03/udld-to-global-or-per-port/#comment-114 Hi, There shouldn't be a problem with udld on only one side as long as you don't configure aggressive udld. Tassos Hi,

There shouldn’t be a problem with udld on only one side as long as you don’t configure aggressive udld.

Tassos

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