Switch Port Settings 10/100 Auto Vers. Fixed

[jpeletz]

I have been in many discussions about setting my switch port speed and duplex to auto or fixed. My take is that the rule of thumb is for workstations or PC's Is to set it for auto. Servers should always be set to fixed. I understand that this is the recommendation of cisco. I have searched the TAC site with no luck in finding the information. Can anyone support this or disprove this?

[svermill]

I have seen this recommendation in more than one Cisco Press book. With regard to servers, the recommendation is that a fixed configuration be used due to the possibility of autonegotiation failure (or "unpredictable results").

[Jaksamit]

Just for a point of reference, I've worked for Sprint for several years in LAN and WAN, and we have always preferred to use fixed speed and duplex settings for all of our servers, workstations and PCs. In the past, settings of 10Mb - half duplex for PCs and the occasional server would be the solution, with 100Mb and full duplex the standard for most servers. Again, it all depends on what you know you have in your network. Today, most of the newer technology, which is primarily what Sprint uses in its Enterprise and backbone networked data centers, utilizes 100Mb and full duplex. I've seen flakey and intermittent connectivity problems solved, by merely setting fixed speed and duplex settings, after troubleshooting everything else. Play with it...it's your network; and good luck.

[ggehle]

Here's what you may be looking for:

http://www.cisco.com/warp/public/473/3.html

They do say that they recommend that auto-negotiate should be used if the device is fully 802.3u (Fast Ethernet) compliant. However, auto-negotiation is an *optional* function under 802.3u, so when in doubt, set speed and duplex.

-Greg

[jpeletz]

My Thanks to everyone that has responded. This is great information. And Thanks Greg for the Link.