PF-NFS Reverse Address-Resolution Protocol, and its problem

RARP lets the PC ask a central server for the PC's own name and Internet address, using the PC's ethernet address (every ethernet card knows its own ethernet address, and can supply it to the host). This is to let the PC participate automatically in changes to the whole net's naming or numbering schemes, and spare it keeping its own copy of its number.

Observations by the support group suggest it's done by:
* broadcasting to all listening hosts to ask what host they're using as a Yellow Pages server (see below), to convert between Internet addresses and host names;
* requesting the host identified by the respones to provide Yellow Pages service for the PC-NFS machine;
* obtaining the PC-NFS machine's own Internet addressing information from that server, to start mounting it.

HOWEVER this sequence apparently fails to distinguish Yellow Pages servers which are actually usable to the ETC subnet; not all the ones in the local domain are. If the PC asks for service from one that isn't, the mounting process will hang. This was happening rather frequently.

RARP has therefore been turned OFF, and the following sequence hardcoded into NETWORK.BAT:
* leave Yellow Pages off
* keep a very small "hosts" table in \NFS which gives the names and Internet addresses of the PC itself, a couple of UNIX hosts which *can* supply Yellow Pages service to the Center's net; and maybe a couple of other useful addresses. Without Yellow Pages, this will be the PC's only way of addressing those machines.
But keep the table *short* -- it will only have to serve until an actual Yellow Pages server can be obtained, a couple of steps later;
* run NET START RDR with the actual name of the PC as parameter; this will cause it to avoid using RARP to obtain the name.
* declare the Yellow Pages domain for which the server is needed -- in our case, "uci-ics" (NOT "ics.uci", which may be found in other contexts).
* use NET YPSET * to request a Yellow Pages server; the choice will be limited to those listed in \NFS\HOSTS.

Yellow Pages will now be ON, and \NFS\HOSTS will probably be completely ignored.

This has to be coded by hand in the NETWORK.BAT file -- it does not appear possible to do it within the NFSCONF program.


Educational Technology Center,
Department of Information and Computer Science,
University of California, Irvine
Irvine CA 92717-3425