We're seeing more and more on-campus offices (we have no residences) buying printers that are coming with 2.4GHz wifi, apparently turned on by default. (Recall that you only get 3 non-overlapping 2.4GHz channels in any area....)
Twice we've seen such devices either broadcasting multiple (12-15) wireless MAC addresses/ESSIDs, or in one case changing MAC address about every 30 seconds. The language in our AUP prohibiting "use that interferes with the intended purpose" was crafted with things like DOS attacks in mind, but doesn't require any change to apply to interfering with campus WiFi service.... David Gillett CISSP CCNP -----Original Message----- From: Peter P Morrissey [mailto:[email protected]] Sent: Tuesday, October 30, 2012 12:10 To: [email protected] Subject: Re: [WIRELESS-LAN] wireless printers in dorms They are not allowed on our network as they don't do 802.1x. We tell them in as many communications as possible that they should bring USB cables. We found that you can get 15 foot USB cables for a couple of bucks in quantity. We give them out during opening to those who didn't get the word and they appear to be very grateful. I couldn't imagine giving up a whole 2.4 channel. I would think that would be pretty devastating to our 2.4Ghz functionality. Pete Morrissey -----Original Message----- From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:[email protected]] On Behalf Of Tom O'Donnell Sent: Tuesday, October 30, 2012 2:53 PM To: [email protected] Subject: [WIRELESS-LAN] wireless printers in dorms I was wondering how other schools handle wireless printers in the dorms. This seems to be the year everyone showed up with one, and they're causing connectivity problems in our 2.4GHz space. Are you able to keep them under control, or do you seek them out and make students to turn them off? They seem to push our AP's to other channels (usually to 1 and 11, since it looks like the printers often use ch 6) to prevent co-channel interference. But sometimes several adjacent AP's end up on the same channel, so either there's still co-channel interference or they're powered down so much that either way it can cause problems through a whole building. Our infrastructure is all Cisco: a WiSM running 7.0.230.0 managing a mix of AP1252's and AP1231's. The AP's have been better at assigning 2.4GHZ channels since we unchecked "Avoid Foreign AP interference" in DCA settings. Our DCA Channel Sensitivity is Medium, and our TPC settings are max. 30dMb, min. -10dBm, threshold -70dBm. We have Client Band Select on, but most of our clients stick with 2.4Ghz, even where 5GHz is available. We've seen noticeable improvement when we're able to locate an interfering printer, disable its wireless, and change channels, but it's a lot of work and not always successful. Lots of knocking on doors, some printers don't seem to let you disable wireless, and sometimes DCA doesn't seem to spread them back among all 3 channels, so we end up setting some channels manually. Are there other useful settings in the WiSM? Any other ideas? Thanks, ---------------------------------------------------------- Tom O'Donnell Senior Manager of Network and Server Systems Information Technology Services University of Maine at Farmington (207) 778-7336 ********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/. ********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/. ********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/.
