University Computing Services
FSU Network Protocol
Standards
Current policy -- created 12/15/97
1.0 The purpose
of standards on the FSU network is to improve the durability and efficiency
of the network. This document will mention network facts at FSU , and
things that you 'should' or 'should not' do on the network here. This
document is subject to change as the network continues to evolve. Please
also see the document about campus naming standards for computers.
1.1 In order to
facilitate network trouble shooting and maintenance you should inform
UCS whenever you add anything to the network at FSU. Contact hostmaster(at)UCS.fsu.edu
to get an IP number for each workstation. You will need to furnish the
location and a contact person and phone number. Contact Office of Telecommunications
whenever you add any hub, switch, or router to the network. Campus network
maps and copies of DNS files are available from UCS to people who support
the campus network.
2.0 The FSU network
has multiple computer communications protocols on its campus network.
TCP/IP is the only protocol that is capable of communication across
The Internet and the only one that is supported by all computers today.
Two other major protocols on the network are IPX (Novell) and Appletalk
(Macintosh). In addition there is some SNA (IBM) and some NetBEUI (Microsoft)
and Decnet (DEC). The Academic computing and Networking Services (UCS)
department supports all protocol flavors on its campus network. However
some are more desirable than others for reasons specified below. In
general, we recommend that you use TCP/IP for network communications
whenever possible and only use alternative protocols if absolutely necessary.
2.1 TCP/IP, IPX,
and Appletalk are routed protocols. SNA and NetBEUI are not routable.
Routers are placed strategically on the network to partition the traffic
into sections (Local Area Networks or LANs) and to direct traffic between
the LANs as needed. Traffic that is between two computers that are located
on the same LAN does not move beyond the router. This routing phenomenon
contains unnecessary traffic locally and makes for more efficient use
of the network. A protocol that is not routable must be bridged between
LANs. When two computers are on the same LAN, if the upstream router
has bridging turned on, their traffic (and all traffic) will be forwarded
to the larger network.
2.2 Without routing
on the network, every workstation would send its packets to every other
work station. The extra traffic requires larger pipes. Also each packet
on a network interrupts each computer on the network whether it is intended
for that computer or not and thereby degrades the computing power of
every computer on the net. Note that switches also help to contain traffic
within physical domains.
2.3 Another phenomenon
about various network protocols is that the systems chat between themselves
to inform each other of their network reachability in addition to any
application level traffic that passes between the computers. Some protocols
are more chatty than others. As a result, cisco recommends that a LAN
can have up to 500 TCP/IP workstations, but only 300 IPX workstations
and only 200 Appletalk stations.
2.4 Each network
protocol has certain unique traits that make if more or less desirable
on a large enterprise network. Most business have less than 50 employees
and therefore the marketplace has fostered protocols designed for small
networks that do not scale well to a large campus network like FSU where
we have approximately 12,000 devices communicating across the local
network.
2.5 SNA has unique
timing constraints with its implementation. A packet must travel to
its destination and be acknowledged within a maximum time or the link
is shut down. Also since it is not routeable, the intervening routers
must enable bridging, which degrades traffic efficiency. SNA exists
on the FSU campus primarily for historical reasons, since it used to
be necessary to communicate with NorthWest Regional Data Center (NWRDC).
NWRDC has upgraded its software to use TCP/IP and all SNA devices on
the FSU campus should be reconfigured to use the TCP/IP protocol.
2.6 Digital Equipment
corporation has deployed multiple protocols some of which (LAT, LAVC,
and MOP) are not routeable. DECnet phase IV is routable and is not carried
on The Internet but ESnet does transport it and it is used at FSU by
some of the research community in SCRI, Physics and Chemistry. DECnet
reassigns layer-2 addressing dynamically and therefore the MAC address
on network routers and bridges which is normally static becomes dynamic.
This makes network trouble shooting for all protocols more difficult.
Whenever possible new computers should implement TCP/IP and not DECnet.
3.0 Appletalk is
routable which help to contain it, but it has 2 problems. First it is
very chatty in the background and that creates an excessive amount of
traffic that interferes with other communications and interrupts other
computer's CPUs. Worse, is that it has an automaticly self-configuring
nature. Just attach a Macintosh to the network and it will 'discover'
a Zone and a cable-range to use. However, if just one device on the
LAN is misconfigured, then it will propagate its bad information endlessly
to other Appletalk computers. Correcting the mess can only be solved
by turning off _ALL_ Appletalk devices on a LAN, _then_ restarting them.
This is difficult and time consuming when many Appletalk devices exist
which no one in a department knows about.
3.1 You must register
with Jim Hoagland at UCS (hoagland(at)UCS.fsu.edu) any Appletalk devices
that you use on the network.
3.2 Macintoshes
that use the latest Mintosh version 8 OS can be configured to use TCP/IP.
This is the preferred implementation. However for this to work, the
server that it communicates with must also be using TCP/IP (Appleshare/IP).
Therefore we strongly recommend that all Macintosh servers implement
Macintosh version 8 OS with Appleshare/IP as soon as possible in order
to facilitate the upgrade of the remaining Macintosh clients on campus.
4.0 Microsoft Windows95
and NT speak TCP/IP which will enable you to communicate with the entire
Internet. They also speak Novell IPX which will enable you to exchange
files with Novell servers and printers that you have password access
to. Win95 and NT also speak multiple other protocols but UCS recommends
that you implement TCP/IP first and only if you need Novell server access
then implement IPX also, but do not use any other protocols on your
Win95 or NT computer.
4.1 Microsoft Win95
and NT have a 'feature' whereby they will automatically 'configure'
themselves when first attached to a network. Whatever the computer first
hears when it attaches to the net, is assumed to be the protocol that
you machine should also use. This is bad, when it hears other computers
that have been mis-configured.
4.2 One of the
incorrect protocol definitions that is possible is to have IPX/SPX configure
itself with the wrong frame type. You should use 802.3 frame type when
using IPX/SPX. To determine which IPX frame type you are using, select
<start> <settings> <control panel> <network>
<IPX/SPX compatible protocol> <properties> <advanced>
<frame type>and then be sure that 'Ethernet 802.3' is selected
for 'Value'.
4.3 Another incorrect
configuration is NetBEUI. It is not routeable and no one should use
NetBEUI at FSU. To see if you have it enabled, select <start>
<settings> <control panel> <network>and if you see
'NetBEUI' then <Remove>it.
4.4 Depending on
which Protocols you have enabled, you may see a different community
when you select <Network Neighborhood> <Entire Network>
We recommend that all NT servers use TCP/IP only and do not enable IPX
unless necessary. As a result, all Win95 clients will be able to access
NT server using only TCP/IP and the network will not use IPX as much.
4.5 Use of the
UCS WINS server is recommended to minimize broadcast traffic. To determine
your setup, right-click <Network Neighborhood> then select <Properties>
<TCP/IP> <Properties> <WINS Configuration> <Enable
WINS Resolution>These WINS servers are wins1.UCS.fsu.edu (128.186.8.9)
and wins.UCS.fsu.edu (128.186.6.18).
5.0 Novell IPX/SPX
is a routable protocol. UCS has defined IPX routing areas that derive
from the primary IP address on each router interface. The derivation
is to turn each IP address byte into an equivalent hexidecimal byte
(therefore 128.186.6.103 becomes 80BA0667).
5.1 Novell (IPX)
should use 802.3 frame type and not allow 'any' frame type since all
stations on the same LAN must use the same frame type to communicate.
In the University Center (A & C but not the end-zone) the frame type
is ethernet_II.
5.2 All future
IPX on campus should use NLSP. This will reduce the RIP/SAP traffic
on a LAN. All future Novell systems on campus, should use Novell 'Netware
IP' and not IPX as a communications protocol.
6.0 With any application
that automatically polls the network, limit the frequency of polling.
For SNMP do not poll any device more than once per minute. For e-mail
clients like Eudora do not check mail more often than once every 5 minutes.
7.0 The following
abbreviations have been used in this document:
| UCS
| Academic Computing
and Networking Systems
|
| CPU
| Central Processor
Unit
|
| DEC
| Digital Equipment
Corporation
|
| DNS
| Domain Name
System
|
| IP
| Internet Protocol
|
| IPX
| Internetwork
Packet eXchange (Novell)
|
| LAN
| Local Area
Network
|
| MAC
| Media Access
Control
|
| NLS
| Netware Link
Services Protocol (Novell)
|
| NWRDC
| North West
Regional Data Center
|
| OS
| Operating
System
|
| RIP
| Routing Information
Protocol
|
| SAP
| Service Advertising
Protocol (Novell)
|
| SNA
| Systems Network
Architecture (IBM)
|
| SNMP
| Simple Network
Management Protocol
|
| SPX
| Sequenced
Packet eXchange (Novell)
|
| TCP/IP
| Transmission
Control Protocol/Internet Protocol
|
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