Cisco Systems 78-11741-02 manual Monitoring and Maintaining IP Addressing, IPC-47

Configuring IP Addressing

Monitoring and Maintaining IP Addressing

To specify a port other than the default port, use the following command in global configuration mode:

Command	Purpose
Router(config)# ip nat service skinny tcp port	Displays port number on which the CCM is listening for
number	skinny messages.

Monitoring and Maintaining IP Addressing

To monitor and maintain your network, perform the tasks described in the following sections. The tasks in the first section are required; the tasks in the remaining sections are optional.

•Clearing Caches, Tables, and Databases (Required)

•Specifying the Format of Network Masks (Optional)

•Displaying System and Network Statistics (Optional)

•Monitoring and Maintaining NHRP (Optional)

Clearing Caches, Tables, and Databases

You can remove all contents of a particular cache, table, or database. Clearing a cache, table, or database can become necessary when the contents of the particular structure have become or are suspected to be invalid.

To clear caches, tables, and databases, use the following commands in EXEC mode, as needed:

Command			Purpose
Router# clear		arp-cache	Clears the IP ARP cache and the fast-switching cache.
Router#	clear	host {name *}	Removes one or all entries from the host name and address
			cache.
Router#	clear	ip route {network [mask] *}	Removes one or more routes from the IP routing table.

Specifying the Format of Network Masks

IP uses a 32-bit mask, called a netmask, that indicates which address bits belong to the network and subnetwork fields, and which bits belong to the host field. This is called a netmask. By default, show commands display an IP address and then its netmask in dotted decimal notation. For example, a subnet would be displayed as 131.108.11.55 255.255.255.0.

You might find it more convenient to display the network mask in hexadecimal format or bit count format instead. The hexadecimal format is commonly used on UNIX systems. The previous example would be displayed as 131.108.11.55 0XFFFFFF00.

The bit count format for displaying network masks is to append a slash (/) and the total number of bits in the netmask to the address itself. The previous example would be displayed as 131.108.11.55/24.

Cisco IOS IP Configuration Guide

IPC-47