Operation Manual

74 NetWare MultiProtocol Router for ISDN 3.1 Installation and ISDN Configuration Guide
Note
Choose Routing Protocols to Link Networks with Dynamic "Nature"
over ISDN has the advantage that you do not have to configure
routes/services manually (exchange of routing and services informa-
tion is the task of routing protocols). Two drawbacks come up with
routing protocols. First, routing tables or link stati need to be veri-
fied/updated over ISDN and, depending on the routing protocol
implementation (distance vector or link state protocol for example),
this is done very frequently. Second, the advantage that network
changes are transmitted can get a drawback as well, because if
servers and services that shall be available in the WAN change very
frequently, ISDN lines are set up or kept up to transmit the changes.
However, a closer look at the behavior each routing protocol is
required, since various mechanisms are implemented with the
distinct routing protocols to optimize their behaviour. These are
discussed below together with recommendations on which routing
protocol to use for which network protocol.
This chapter does not discuss any of the tunneling possibilities, for example
transport of IPX or AppleTalk (AURP) encapsulated/tunneled in TCP/IP.
Further, the various routing protocols are not described to their full extend,
but are only discussed in regard to what is important in conjunction with
ISDN use.
When setting up your WAN links over ISDN, have a look at your
LAN and the LANs that you wanto to interconnect over your router
and decide whether they are of a more static or dynamic nature.
Whenever they are more dynamic, it is more comfortable and there-
fore recommended to use a routing protocol to link them over ISDN,
disregarding whether you use IPX or AppleTalk. For TCP/IP, the
general recommendation to use static routes is still valid, but prefer-
ences can be made if you choose to use a routing protocol instead of
static routes.
Recommendations that go together with the use of any of the routing
protocols:
- Use FILTCFG to filter out routes/services, single IPX nodes, IP
hosts, NICs, packet types and for IP in additon IP (e.g. telnet, ftp)
that shall not gain access to remote sites over ISDN or be
transmitted over ISDN.
configuration overview.pm6 28.05.97, 00:0374