RE: [WIRELESS-LAN] Cisco WLC DHCP Proxy
Hi Oliver- With 5.2.193 code and DHCP proxy enabled, we had a fairly substantial issue at work causing trouble. I've not heard of other cases like ours, so I don't want to add too much confusion to the mix- but will certainly provide details off list if anyone is curious. To answer your other questions- we have ran with the proxy on since initial system rollout because it was the default and was recommended. It does provide some protection of your DHCP servers by obscuring them behind a virtual IP address, and we have had no issues with it prior to 5.2.193. If you really don't need it, don't use it. -Lee Lee H. Badman Wireless/Network Engineer Information Technology and Services Syracuse University 315 443-3003 -Original Message- From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:wireless-...@listserv.educause.edu] On Behalf Of Oliver Gorwits Sent: Wednesday, October 28, 2009 7:53 PM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: [WIRELESS-LAN] Cisco WLC DHCP Proxy -BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Hi folks, Lee H Badman wrote: do you have the DHCP proxy function enabled? So far we've had the DHCP proxy function disabled on our Cisco wireless controllers. This is the global option, it's not configurable per WLAN/Dynamic Interface (that I can tell, at least). Lee mentioning this in the other thread intrigued me. What are people's experiences and opinions of this feature? Are there benefits to either having DHCP proxy off, or on? regards, oliver. - -- Oliver Gorwits, Network and Telecommunications Group, Oxford University Computing Services -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.9 (Darwin) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAkro2VAACgkQ2NPq7pwWBt68qgCcCL7MAUH9Lc0JZXNvU21XSE2J VuUAniEiikFt2MWAVMPzrasT8jGjC2TG =sKN9 -END PGP SIGNATURE- ** 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/.
RE: [WIRELESS-LAN] Cisco WLC DHCP Proxy
Hi Lee- Thanks for the tip: we are on a pre 5.2.193 and do see dhcp proxy was currently enable as default setting . So somehow during upgrade from 4.2.x. to 5.2.193 or better, something change that causes issue that need dhcp proxy to disable, I am hearing you correctly ? If you have to go off-list, please unicast. We are testing 6.x. and probably migrate directly to 6.x when thing stable. But I am also looking at 5.2 for a more conservative move. Best Regards, Loc Pham, # 17030 , office 415-353-4492 IT Enterprise Security Services, UCSF Medical Center Where self-healing network is building on . -Original Message- From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:wireless-...@listserv.educause.edu] On Behalf Of Lee H Badman Sent: Thursday, October 29, 2009 5:35 AM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Re: [WIRELESS-LAN] Cisco WLC DHCP Proxy Hi Oliver- With 5.2.193 code and DHCP proxy enabled, we had a fairly substantial issue at work causing trouble. I've not heard of other cases like ours, so I don't want to add too much confusion to the mix- but will certainly provide details off list if anyone is curious. To answer your other questions- we have ran with the proxy on since initial system rollout because it was the default and was recommended. It does provide some protection of your DHCP servers by obscuring them behind a virtual IP address, and we have had no issues with it prior to 5.2.193. If you really don't need it, don't use it. -Lee Lee H. Badman Wireless/Network Engineer Information Technology and Services Syracuse University 315 443-3003 -Original Message- From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:wireless-...@listserv.educause.edu] On Behalf Of Oliver Gorwits Sent: Wednesday, October 28, 2009 7:53 PM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: [WIRELESS-LAN] Cisco WLC DHCP Proxy -BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Hi folks, Lee H Badman wrote: do you have the DHCP proxy function enabled? So far we've had the DHCP proxy function disabled on our Cisco wireless controllers. This is the global option, it's not configurable per WLAN/Dynamic Interface (that I can tell, at least). Lee mentioning this in the other thread intrigued me. What are people's experiences and opinions of this feature? Are there benefits to either having DHCP proxy off, or on? regards, oliver. - -- Oliver Gorwits, Network and Telecommunications Group, Oxford University Computing Services -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.9 (Darwin) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAkro2VAACgkQ2NPq7pwWBt68qgCcCL7MAUH9Lc0JZXNvU21XSE2J VuUAniEiikFt2MWAVMPzrasT8jGjC2TG =sKN9 -END PGP SIGNATURE- ** 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/.
RE: [WIRELESS-LAN] Self-assigned IP on Macs
We encountered the same issue. However, not all snow leopard clients have this problem. Some of them work well; some of them could not get IP address from DHCP server occasionally; and some of them could not get IP address for the whole day. We contacted with Apple, they said they noticed this problem, and a new patch will be published in the middle or end of November. Linchuan Yang Wireless Networking Analyst Network Assessment and Integration, IITS-Concordia University Tel: (514)848-2424 ext. 7664 -Original Message- From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:wireless-...@listserv.educause.edu] On Behalf Of Anthony Croome Sent: October 28, 2009 6:26 PM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Re: [WIRELESS-LAN] Self-assigned IP on Macs Update for my uni's problem. Our engineers are 100% convinced it's a MAC OS issue. We are not sure when the problem was introduced. When it is working we see the discover, offer, ack, in the DHCP daemon logs. Then at a random, intermittent time the DHCP daemon will decide to stop listening to dhcp packets being received on wireless, it logs the discover but not the offer. Wireshark is showing the offers being received but the DHCP daemon doesn't log them. There is no difference in the contents of the DHCP offer when it is working vs when it isn't. We are going to escalate it to Apple, as there isn't anything else we can see to try. Anthony -Original Message- From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:wireless-...@listserv.educause.edu] On Behalf Of Lee H Badman Sent: Friday, 16 October 2009 10:16 AM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Re: [WIRELESS-LAN] Self-assigned IP on Macs Has anyone gotten any approved suggestions for how to deal with these Apple issues from Cisco, beyond just trying things that seem to sometimes help? It is frustrating how the friendly and trouble-free Apple devices tend to be the least friendly and most troubling devices on the WLAN. A little bit of techno-irony to this:) -Lee From: The EDUCAUSE Wireless Issues Constituent Group Listserv [wireless-...@listserv.educause.edu] On Behalf Of Jeffrey Sessler [j...@scrippscollege.edu] Sent: Thursday, October 15, 2009 7:56 PM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Re: [WIRELESS-LAN] Self-assigned IP on Macs In 6.0, the code for world-mode didn't make it into the controller, but I believe it's in the AP's IOS commands, so it can be toggled but takes a little more effort. Jeff Garry Peirce 10/15/09 2:16 PM Perhaps I was erroneous in equating the two through a Cisco doc referencing DTPC to world-mode. 'When you enable Dynamic Transmit Power Control (DTPC), access points add channel and transmit power information to beacons. (On access points that run Cisco IOS software, this feature is called world mode.)' DTPC does appear to be CCX related, so it is likely irrelevant with regard to the mentioned Apple/Broadcom bug. Running 6.0.182, 'config 802.11a world-mode' is not an available option. 'config 802.11a dtpc' is. 'show 802.11a' will show the status of DTPC. I'll inquire w/Cisco. -- -Original Message- From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:wireless-...@listserv.educause.edu] On Behalf Of Matt Grover Sent: Thursday, October 15, 2009 2:51 PM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Re: [WIRELESS-LAN] Self-assigned IP on Macs It's under: show 802.11a(or b) -Matt Bob Richman wrote: So, how about the show command that displays the current setting? -Original Message- From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:wireless-...@listserv.educause.edu] On Behalf Of Matt Grover Sent: Thursday, October 15, 2009 1:21 PM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Re: [WIRELESS-LAN] Self-assigned IP on Macs Actually, if you are talking about specifically world-mode it's under: CLI: config 802.11a world-mode orconfig 802.11b world-mode -Matt -- Matt Grover === University of Florida Sr. Network Engineer=== http://net-services.ufl.edu m...@ufl.edu=== Florida Lambda Rail (352)273-1061 === http://www.flrnet.org/ ** 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/. ** Participation and subscription information for this EDUCAUSE
