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Doug Nelson wrote: >>Hello network admin, >> I am wondering what is happening with wireless networking on campus. I >>have ask the computer center consultants and they had no info. I have a >>new portable that came with wireless built in. I noticed that there is a >>wireless router from OMERAD that it can connect to. Am I allowed to use >>this connection and what are the access procedures? >> On a related note, I have noticed that sometimes when using DHCP >>that I get connected to an off campus DHCP server and am assigned an >>incorrect DHCP ip address. If I do a ipconfig /release and renew, it >>will correct itself but not always on the first try. Is there a way to >>force DHCP to connect to our DHCP server 35.8.2.22 ? I have set the >>default gate way to 35.8.2.3 I am running Win XP pro with all the latest >>updates. Is there anything else that will affect this or cause this problem? >> >> > >There are no centrally-supported wireless facilities on campus, so any you >find would belong to a specific department or individual. There have been >a number of discussions about wireless in the Network Communications >Committee and elsewhere, but no funding for any centralized wireless. There >are some pockets of public wireless that are beginning to materialize, such >as at the Main Library. > >As for DHCP, if you get an incorrect IP address (not starting with 35), then >there is likely to be a "rogue" DHCP server within your building. Often, this >is caused by an incorrectly-configured Wireless unit, or some type of router >(e.g. a cable/DSL router, incorrectly wired or configured). The best way to >force DHCP to the correct server is to find and eliminate the incorrectly- >configured system. > > On Friday afternoon I was able to locate the "rogue" server in Fee Hall. We had notice that that our DHCP clients were sometimes getting inappropriate IP settings (addresses in the 192.168.0.X range with a subnet mask of 255.255.255.0) and not functioning properly. I ran "ipconfig /all" on such a mis-configured Win2k machine and got the IP address of the DHCP server (192.168.0.1) , ping'ed it arp'ed it and got the MAC address (00-09-5b-2a-c2-24) and determined that it was a "Netgear" device. I remembered that someone in West Fee had recently installed such a device. When I went to inspect it, I found that the MAC address matched, and that the the second port on the router had been pluged into the building network instead of the first port (marked "internet" on the box itself). When I inquired the owner as to why it had been set up that way he said that he was told to do this by people from the College of Engineering to improve its performance. I suspect that there was some mis-communication there. I carefully explained the difficulties that this was casing on our network and unplugged the box. >The approach that I recommend for finding a rogue DHCP server is to make a >note of your DHCP settings, in particular the DHCP server address. Try to >ping that address, and then do "arp -a", and see if the Ethernet address >shows up. If so, the Ethernet address can be used to locate the device >within the building. You can call in a network trouble report (call 353-4602), >and pass on the relevant details, and we can assist in locating the errant >device. > > >Doug Nelson [log in to unmask] >Network Manager Ph: (517) 353-2980 >Computer Laboratory http://www.msu.edu/~nelson/ >Michigan State University > > > -- ------------------------------------------------------------------------- Stephen W. Asman | Room A339 East Fee Hall Microcomputer Hardware & Software Coordinator| Michigan State University MSU-COM | East Lansing, MI 48824 [log in to unmask] | (517) 432-0492