Cisco for me !: IP addresses :

IP Addresses

Current challenges in IP Addressing

An IP address consists of a 32-bit number with two components: a network address and a node.

The incredible growth of the Internet has resulted in following challenges:

IP Addressing Solutions

Solutions have been developed to slow the depletion of IP addresses and to reduce the number of

Internet route table entries by enabling more hierarchical layers in an IP address.

These solutions include the following:

Variable Length Subnet Masks

The VLSMs are commonly used to maximize the number of possible addresses available for a

network. The benefits if VLSMs are:

• Even more efficient use of IP addresses

• Greater capability to use route summarization

Route Summarization

Route summarization can reduce the number of routes that a router must maintain because it is a

method of representing a series of network numbers in a single summary address.

Cisco routers manage route summarization in two ways:

• Sending route summaries

• Selecting routes from route summaries

CIDR

CIDR is a mechanism developed to help alleviate the problem of exhaustion of IP addresses and

growth of routing tables.

Redistribution Implementation Guidelines

• Be familiar with your network and your network traffic

• Do not overlap routing protocols

• One-way redistribution

• Two-way redistribution

NAT

Network Address Translation can be used to merge two large networks without having to readdress

the whole network. Another function of NAT is overloading inside global addresses.

This process allows several inside addresses to use a single IP address. NAT can also use a pool

of addresses or multiple interfaces.

Cisco for me !