The IPv6 mobility feature, defined in RFC 3775, Mobility Support in IPv6, allows users to stay connected while moving about the network. An IPv6 mobile node has a home address on its home network and a care-of address on its current network. A node communicating with a mobile node is called a correspondent node of the mobile node. The association between the home address and the care-of address of a mobile node is known as a binding. When a mobile node roams away from ..
In Cisco routers, IGRP does not recognize the 0.0.0.0/0 route as the default route. It uses its own method of propagating default route with the ip default-network command. The ip default-network command specifies a major network address and flags it as a default network. This major network could be directly connected, defined by a static route, or discovered by a dynamic routing protocol. The network specified by the ip default-network command must be in the routing table b..
Catalyst Configuration File Management
For complete system recovery, make sure that you have a copy of each Catalyst's configuration file stored somewhere other than on the Catalyst itself. If anything happens to the Catalyst Supervisor module, you might not be able to recover the configuration file. It is a crime to have to rebuild the entire configuration file from scratch during a system outage when it is easy to create a backup on a network accessible machine. Through TFTP, you can store your configuration fi..
SMTP, defined in RFC 821, is used to provide e-mail services to IP devices over the Internet. Typically, two mail servers "talk" SMTP to exchange e-mail. After the e-mail is exchanged, the users can retrieve their mail from the mail server and read it. This can be done using any mail client, such as Pine, Eudora, Outlook, and so on, which use different protocols, such as Post Office Protocol 3 (POP3), to connect to the server. SMTP uses well-known ports TCP port 25 and UDP po..
Changing Administrative Distances
When dealing with administrative distances, always bear in mind that they only affect route selection on this particular router. Administrative distances are not distributed by the routing protocols. However, they can affect the routing protocols. Distance vector algorithms in particular only distribute the routes that are used locally. Adjusting the administrative distance could change which routes are used. So you should always be extremely careful when adjusting administra..
