6,1.2, Reducing Network Overhead - Sun Microsystems Sun Workstation 100U System Manager's Manual

System Set-Up and Operation Sun 100/150 Installation Manual
:/1=
Fantasy Local Net 192.9.200 -- 10Mb/s Ethernet - Engineering
:/1=
192.9.200.1
192.9.200.2
192.9.200.3
[ etc. ]
jekyll loghost date host
usher
lenore
:/1=
Fantasy Local Net 192.9.4 -- 10Mb/s Ethernet - Marketeering
:/1=
192.9.4.1
192.9.4.2
192.9.4.3
192.9.4.4
( etc. ]
quasimoto
godzilla
rodan
jekyll-hyde
For administrative puposes, it makes sense to use two similar hostnames - people on both
nets can address the machine by the same name, and you can tell the difference.
2. Edit / etcl rc.local, and add an 'ifconfig' line mapping the machine's second hostname and
Ethernet Board. Taking our example above, here is the relevant line from the file before:
letc/ifconfig ecO jekyll -trailers up
and after:
letc/ifconfig ecO jekyll -trailers up
letc/ifconfig ecO jekyll-hyde -trailers up
3. Finally, if you wish, you can copy the gateway's
I
etcl ho,t, file to all machines on both net-
works. This is not necessary, but may make for ease of administration.
6.1.2. Reducing Network Overhead
It is possible to have most of the advantages of living in a network environment without run-
ning the network daemons -
rwhod{8C) and routed{8C) -
on every machine. For systems
with only 1 MByte of local memory, it may be desireable to disable the daemons, or run them
only on specific machines, so that the space consumed by them can be made available for other
purposes. When running, routed and rwhod are actively doing something many times a minute,
and so leave many of their pages in memory almost all the time. For a 1-MByte system with
600K of available user memory, the memory thus effectively consumed is about 7%. Combined,
both daemons use up about 14% of available user memory.
rwhod allows the programs rwho{IC) and ruptime{IC) to return status information about
machine usage of hosts on the local network. Unless you really need this information, we sug-
gest you do not run rwhod. By default, rwhod is not run. If you choose to run it, remove the
comment mark (a ':/1=' in column 1) from the following line in
I
etcl rc:
:/I=lusr/etclin.rwhod & echo -n ' rwhod' >/dev/console
Normally, routed, the routing daemon, runs on each Sun Workstation, and maintains network
routing information that enables your machine to pick the best path for sending packets to
external networks. routed consumes a small amount of memory and CPU time running an algo-
rithm to keep accurate information about the topology of the local network.
Whether or where you should run routed depends on your system configuration. In general, if
you have more than 1 MByte of memory in your workstation then it probably isn't worth
6-2
Revision H of 12 March 1984