Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!wuarchive!wugate!uunet!ibmarc!drake
From: drake@ibmarc.uucp (Sam Drake)
Newsgroups: comp.sys.ibm.pc.rt
Subject: Re: steps to setup ethernet link on PC/RT requested
Keywords: ethernet PC/RT baseband addressing distributed services
Message-ID: <1122@ks.UUCP>
Date: 6 Oct 89 00:33:50 GMT
References: <809@jonlab.UUCP>
Sender: news@ibmarc.UUCP
Reply-To: drake@ibmarc.UUCP (Sam Drake)
Organization: IBM Almaden Research Center, San Jose
Lines: 85

In article <809@jonlab.UUCP> jon@jonlab.UUCP (Jon H. LaBadie) writes:

>1. TCP/IP vs. Distributed Services
>   I'm not sure how these tie together.  Seems that each has its own set
>   of administrative requirements.

Distributed Services allows RTs to share filesystems over the network.
Files on one RT can be accessed from the other.  DS uses SNA, not TCP/IP,
as its lowest level transport mechanism, and so there is no overlap...
they do indeed require separate administration.

DS does roughly the same thing as NFS does, but in a different manner...
arguably superior in many ways.  You can / should choose ONE of them to
satisfy your remote file access requirements.  If all you have are RTs,
DS is probably the way to go; if you need to interoperate with other
vendors' equipment then use NFS.  NFS uses TCP/IP.


>2. Addressing
>   Node name - set via "uname -S", used only by uucp??

True.

>   Node id number - printed by "uname -a" and listed as the local
>     "nickname" when entering "ndtable".  What is its use and how
>     (or should) it be set.
>   Internet address - big HUH?  Seems to be required at many points.
>     But I have no plans to get onto any external Internet.  Is it
>     still required?  How is it chosed/set?
>   Domain name - same HUH? as Internet address.
>   Hostname - seems to be set with "hostname".  Should this be the
>     same as Node name?

Internet addresses must be assigned for each machine, each machine must
have a hostname/nodename, and you must have a domain name.  If you really
truly will never hook up to any other network you could make up the
internet address (use a class C address, see the TCP/IP for AIX manual),
and you could make up a domain name.  Since I doubt it's possible to
say that you'll never want to hook up, it might be worth the exercise
to get formally assigned domain names and IP addresses.  

An example:

My machine's node name is "sd2", my site's domain name is "almaden.ibm.com".
Therefore my "hostname" in /etc/rc.tcpip is "sd2.almaden.ibm.com".
So is my nodename in /etc/master.

>3. Sendmail.cf and associated needs
>   I think I have a minimum config established, but some assurances
>   would be welcome.

The supplied /usr/adm/sendmail/sendmail.cf needs to be modified to
include the machine's node name in the indicated place, then run 
"sendmail -bz".  That's it.

>4. NFS/YP software
>   This has not been obtained.  Is it needed, would it be nice, for
>   our basic requirements?

See above.

>5. Cabling
>   We have appropriate coax to connect the two systems.  It would
>   mean routing the cable through the dropped ceiling between offices.
>   An alternative (attractive physically and visually) is to use the
>   already installed coax for our synchronous terminals.  Each office
>   has a number of these going to a patch panel in the computer room.
>   It would be simple to run coax to the wall plate, and jumper the
>   two connections at the patch panel.  Is this a no-no because of
>   the different types of coax cable?

Doesn't sound promising.  You might look at "Lattisnet" (sp?) equipment,
they sell boxes that let you run Ethernet over existing phone wiring ...
might be easier to set up and install than traditional Ethernet cabling.
I have no connection with this company, and I'm certainly not speaking
for IBM in any way.

>I would appreciate any input you might have; posted or mailed.  I would
>prefer mailings however as the propogation delay on new articles is
>about 3 days to my site.  Mail is nearly immediate.

Oops.


Sam Drake / IBM Almaden Research Center