For CSOs: Various procedures for avoiding broken profiles, DHCP component errors, etc.

1. When the IP address of a DICE machine is removed from our DNS, the machine's LCFG profile must be changed to use either the dice/os/unallocated.h or the dice/os/junk.h header, as appropriate.

   Failure to do this results in broken profiles and verbose errors from the DHCP and PXE components.

2. Any includes for studentlab or office headers (e.g. dice/options/office-forum.h) must be removed from the LCFG profile. This helps the LCFG server avoid unnecessary recompilation of profiles.
3. The profiles of self-managed machines which have not been allocated fixed IP addresses should always use the dice/os/placeholder.h header. The dice/os/selfmanaged.h header should only be used for self-managed machines which have been allocated fixed addresses.

   Failure to do this results in verbose errors from the DHCP and PXE components.

4. For a self-managed machine which has been allocated a fixed IP address, but for which the MAC address is not yet known, include the line #define NO_DHCP at the top of the profile.

   Failure to do this results in verbose errors from the DHCP and PXE components.

5. If a DICE machine is taken out of service and its IP address removed from our DNS, it must be reinstalled before it is reconnected to our network. In such cases, place an obvious 'REINSTALL ME' comment in the machine's profile, and a similar notice on the machine itself.

   If this isn't done, then, if the IP address is reassigned and some time later the machine just put back into service, there will be a conflict between the two would-be users of the address. This will cripple the network performance for both machines, and will annoy everyone who is on the 'arpwatch' recipient list.

   Note that it isn't enough to assign a new address in the DNS file. Both machines will have the disputed address cached on disc, and will attempt to use it until one of them is reinstalled or manually tidied up. Reinstalling is the easiest solution..

6. If a machine with a fixed IP address (whether DICE or self-managed) is taken out of service, then any network port which has been MAC-locked to that machine should be modified so that no reference to the machine remains in place. This typically affects AT lab machines, and what needs to be checked are the corresponding atnet/*.ports files.

   Failure to do this results in broken *.ports files, and resulting error messages.

7. Whenever an assigned IP address is removed from the DNS, please comment out that IP address in dns/inf, and add a prominent comment which makes it very obvious that the address can be reused. That is, edit dns/inf like so:

   Before:

     129.215.25.9    oldmachinename

   After:

     #129.215.25.9   CAN BE REUSED

-- IanDurkacz - 02 Jul 2012