Specifications

1-10
Cisco AS5x00 Case Study for Basic IP Modem Services
11/24/1999
Section 1 Network Design and Case Study Overview
Configuration Design Parameters
Note
A simple IP address strategy is used for this case study. Scaling IP addresses is
outside the scope of this document.
NAS loopback 0 172.22.99.0/24 Identifies the router with a unique and stable IP address for
network management purposes. One IP address from a
common address block is assigned to each network device.
This technique enables the network operations center (NOC)
to more easily perform security filtering.
One class C subnet that used to identify devices can support
254 distinct nodes with unique loopback IP addresses.
NAS loopback 1 172.22.90.0/24 Used to host a pool of IP addresses for the remote nodes.
In this way, one route is summarized and propagated to the
backbone instead of 254 host routes.
Setting up interior gateway protocols (IGP) is outside the
scope of this document. For example, OSPF and EIGRP.
1. The /17 means there are 17 bits in the subnet mask. For /26, there are 26 bits in the subnet mask and so on.
Table 1-5 IP Subnetting Plan
Network Name Assigned Subnet Description