If you are running Cisco switches, verify that spanning-tree portfast is enabled on all non-switch uplink ports.
Run wireshark on an effected workstation. Examine the following traffic: DHCP discovery (From Workstation) DHCP Offer (From Server) DHCP Request (From Workstation) DHCP Ack (From Server) This may give you some deeper insight as to what is going on behind the scenes. As to what may have changed: A change in the network topology (A switching loop, let's say or too many switches in line) could have changed the time it takes a broadcast to propagate. Your DHCP server, for what ever reason, may have exhausted it's scope (I've seen this behavior with a misbehaving NIC and/or malware). Just brainstorming for you.... HTH -A On Sat, Sep 25, 2010 at 10:45 PM, Charlie Kinsella <ckinse...@dixonschools.org> wrote: > Did you add any new switches in the building? Aside from the wireless any > new anything? > > Charles Kinsella > Technology Director > Dixon Public Schools > ckinse...@dixonschools.org > (815) 284-7725 > > > ________________________________ > > Maybe I am not being clear. The DHCP server is not dishing out ANY > addresses to ANY device that is contacting it. I tried a few IPods and a > few workstations and when I set them to automatic discover / DHCP - they try > for a while and then fail. The PC boxes tell me I have a limited connection > and when I check the IP "assigned" to the box it is a 169.X.X.X address > which is not really an assigned address - but what a windows box will plug > in if the DHCP process fails. > > Now the weird parts > - This was all working fine before late Thursday / Friday AM > - From what I can tell the DHCP server IS up and running > - When I use the Microsoft Rogue DHCP tool to see if there is more than one > DHCP server on the network it sees the one DHCP server (The IPCop box) AND > it reports a valid IP that the DHCP server would be handing out > - When I down the DHCP server and run the Rogue DHCP server tool I see NO > DHCP servers on the network. > > So - the DHCP is there, it is running, it is handing out IP's to the Rogue > DHCP server tool > BUT > No device / PC etc. is successful in communicating with the DHCP server and > assigning an IP that the server is providing. > > Any ideas would be GREATLY appreciated! > > > | Subscription info at http://www.tech-geeks.org | > -- "Don't ask yourself what the world needs. Ask yourself what makes you come alive and then go do that. Because what the world needs is people who have come alive." -Dr. Howard Thurman ****************************** Aaron Keith Hackney aa...@aaronkeithstudios.com Cell 210.325.2196 ****************************** | Subscription info at http://www.tech-geeks.org |
