Information Technology Reference
In-Depth Information
Table 10-7
Link-State Database for R5
continued
Connected to neighbor
R3
on network
10.7.0.0/16
, cost of
10
Connected to neighbor
R5
on network
10.10.0.0/16
, cost of
20
Has a network
10.8.0.0/16
, cost of
2
R5 Link States:
Connected to neighbor
R2
on network
10.9.0.0/16
, cost of
20
Connected to neighbor
R3
on network
10.6.0.0/16
, cost of
5
Connected to neighbor
R4
on network
10.10.0.0/16
, cost of
20
Has a network
10.11.0.0/16
, cost of
2
Shortest Path First (SPF) Tree
Because all LSPs have been processed using the SPF algorithm, R5 has now constructed the complete
SPF tree. Table 10-8 repeats the SPF tree for R5 that you determined earlier. Fill in the table again
here.
Table 10-8
SPF Tree for R5
Destination
Shortest Path
Cost
R1 LAN
R5 to R3 to R4 to R1
27
R2 LAN
R5 to R2
22
R3 LAN
R5 to R3
7
R4 LAN
R5 to R3 to R4
17
Using this tree, the SPF algorithm results indicate the shortest path to each network. Only the LANs
are shown in the table, but SPF can also be used to determine the shortest path to each WAN link net-
work shown in Figure 10-3 shown earlier. Complete the missing information in the following list for
R5's shortest path to each network:
Network 10.1.0.0/16 via
R5
Serial
0/0/1
at a cost of
27
■
Network 10.2.0.0/16 via
R2
Serial
0/0/0
at a cost of
30
■
Network 10.3.0.0/16 via
R3
Serial
0/0/1
at a cost of
7
■
Network 10.4.0.0/16 via
R3
Serial
0/0/1
at a cost of
25
■
Network 10.5.0.0/16 via
R2
Serial
0/0/0
at a cost of
22
■
Network 10.7.0.0/16 via
R3
Serial
0/0/1
at a cost of
15
■
Network 10.8.0.0/16 via
R3
Serial
0/0/1
at a cost of
17
■
Implementing Link-State Routing Protocols
The following sections include exercises covering the advantages and requirements of link-state
routing protocols.
