Network issues

Issue Occurs:

Only seems to occur on IP4 networks. Haven't testing on an IP6 network.

Symptom:

A machine that was recently moved or restaged with a new OS now will not receive an IP via DHCP even though nothing has changed in any other settings on the network.

Solution:

• Give the machine a static IP.
• Log in as a network user. This should work now if your network allows static IPs.
  
• Ping everything, as many different places on the network as you can think of.
• Set the machine back to DHCP and reboot.
• Should be fixed. Log in as a network user and use the machine as normal.
  

Comment:

The routers/switches all over the building have little brains. They attempt to speed things up by remembering important information and acting on those memories. That is why something changing, like the location or OS of a machine, might throw of the tuning of the network to the point where a machine cannot contact the DHCP server.

In order for a machine to get an IP from a DHCP server, this strange packet must be transmitted across the network and the "kindness of strangers" depended upon to rout that packet to the DHCP server and back to the box again. There is all kinds of mysterious bookkeeping involved. This issues is the result of that bookkeeping breaking down.

Switches and routers have have brains, but not intelligence. When you have a herd of stupid boxes directing traffic, you get lost packets.