Information Technology Reference
In-Depth Information
23.11 Example network
A university network is shown in Figure 23.11. The connection to the outside global Internet
is via the Janet gateway node and its IP address is
146.176.1.3
. Three subnets,
146.176.160
,
146.176.129
and
146.176.151
, connect the gateway to departmental
bridges. The Computer Studies bridge address is
146.176.160.1
and the Electrical De-
partment bridge has an address
146.176.151.254
.
The Electrical Department bridge links, through other bridges, to the subnets
146.176.144
,
146.176.145
,
146.176.147
,
146.176.150
and
146.176.151
. The
main bridge (Figure 23.12) into the department connects to two Ethernet networks of PCs
(subnets
146.176.150
and
146.176.151
) and to another bridge (
Bridge 1
).
Bridge 1
connects to the subnet
146.176.144
. Subnet
146.176.144
connects to workstations and
X-terminals. It also connects to the gateway
Moon
that links the Token Ring subnet
146.176.145
with the Ethernet subnet
146.176.144
. The gateway
Oberon
, on the
146.176.145
subnet, connects to an Ethernet link
146.176.146
. This then connects to the
gateway
Dione
that is also connected to the Token Ring subnet
146.176.147
.
The topology of the Electrical Department network is shown in Figure 23.12. Each node
on the network is assigned an IP address. The
hosts
file for the set-up in Figure 23.12 is
shown next. For example the IP address of
Mimas
is
146.176.145.21
and for
miranda
it
is
146.176.144.14
. Notice that the gateway nodes,
Oberon
,
Moon
and
Dione
, all have
two IP addresses.
Computer
Studies
bridge
146.176.160.1
Global
Internet
146.176.160
Mechanical
Department
bridge
146.176.129.1
146.176
Janet
gateway
146.176.1.3
146.176.129
146.176.151
146.176.144
146.176.145
Electrical
Department
bridge
146.176.147
146.176.150
146.176.151
146.176.151.254
Figure 23.11
A university network
Contents of host file
146.176.1.3 janet
146.176.144.10 hp
146.176.145.21 mimas
146.176.144.11 mwave
146.176.144.13 vax
146.176.144.14 miranda
146.176.144.20
triton
146.176.146.23
oberon
146.176.145.23
oberon
146.176.145.24
moon