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100 Full versus 10 Half for Switch Ports.... Ideas?

I'm debating whether to connect my Cisco 1231G and 1242AG stand-alones to switch ports set to 100 Full or set to 10 Half. I'm told we'd be able to do error checking if we set the switch ports to 10 Half, and that 100 Full wouldn't give us much of an advantage if our users don't use very intense applications wirelessly. I could use any input I can get!

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Hall of Fame Super Red

Re: 100 Full versus 10 Half for Switch Ports.... Ideas?

Hi Emily,

From the release notes for 12.3(7)JA1:

"Use Auto for Ethernet Duplex and Speed Settings.

Cisco recommends that you use auto, the default setting, for both the speed and duplex settings on the access point Ethernet port. When your access point receives inline power from a switch, any change in the speed or duplex settings that resets the Ethernet link reboots the access point. If the switch port to which the access point is connected is not set to auto, you can change the access point port to half or full to correct a duplex mismatch and the Ethernet link is not reset. However, if you change from half or full back to auto, the link is reset and, if your access point receives inline power from a switch, the access point reboots."

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

Here is a link to the actual doc.

http://www.cisco.com/en/US/products/hw/wireless/ps430/prod_release_note09186a0080539c21.html#wp76599

Hope this helps!

Rob

Please remember to rate helpful posts......

New Member

Re: 100 Full versus 10 Half for Switch Ports.... Ideas?

Well, first off, whichever you use, if you don't leave auto-sensing on both sides, be sure to hard set both the AP and the switch to the same settings. To be honest, when connecting Cisco devices to other Cisco devices, it isn't so much of a problem, it's just good practice. When you connect different vendors, all sorts of problems occur if theres miss-matches. Also auto-sensing between different vendors can be messy, but that's beside the point.

I don't know what your switches are, but personally when in doubt, I'd set the ports to 100 full duplex on the APs and your switches. As long as this doesn't give you any connection issues (particularly if it's a non-Cisco switch), stick with it. Of course your bottleneck will still be the 802.11 interface speed. So, what you also might want to do, is prune unnecessary vlans from the AP port trunk (assuming it's trunking). In addition, if you've got a very very busy network, you might want to set some aggregate policers on the switchport, and maybe limit the broadcast multicast rates too. This isn't normally necessary but it's an option especially if you want to run WiFi IPT.

If you only set 10 half duplex on your switchports, then they will run a little slower (bit rate wise anyway) than the 802.11 interface, so I think you’ve been miss-informed on that one. Effectively an 802.11g interface with 54Mbps clients could be running around 25Mbps half duplex max. If you had 802.11a interfaces too, potentially you’d be running well in excess of 10 half duplex.

Hope that helps.

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