CCNA Help Guide

CAD for VLSI Design I

2011-02-08T01:26:00.000-08:00

The below mentioned chapters cover the Front end design aspects of Very large Scale Integration Chip manufacturing Cycle. It also teaches verilog Hardware Description language (HDL) that shall help in describing a circuit to the tools for simulation and further processing of the same towards manufacturing the chip.

Computer Networking

2011-01-31T06:51:00.000-08:00

Below mentioned presentations covers various important topics in Computer Networking viz. OSI reference model, topology design, maccess control level, LAN design, IEEE LAN standards, Logical link control protocols, HDLC, ALOHA, Slotted ALOHA, FDDI, client server model, network layer level, WAN, MAN, TCP/IP, Novel Netware, Routers, Bridges, Gateways. X.25, NETSCAPE, MOSAIC, Transport layer, upper layers, e-mail and other applications

Wildcard Bits

2008-09-13T19:08:00.000-07:00

How to Check the Corresponding Address Bits

–0 means check value of corresponding address bit.
–1 means ignore value of corresponding address bit.

Wildcard Bits to Match a Specific IP Host Address

–For example, 172.30.16.29 0.0.0.0 checks all the address bits.
–Abbreviate this wildcard mask using the IP address preceded by the keyword host (host 172.30.16.29).

Wildcard Bits to Match Any IP Address

–Accept any address: 0.0.0.0 255.255.255.255.
–Abbreviate the expression using the keyword any.

Wildcard Bits to Match IP Subnets

Access Lists

2008-08-23T19:21:00.001-07:00

What Are Access Lists?
–Standard
- Checks source address
- Generally permits or denies entire protocol suite
–Extended
- Checks source and destination address
- Generally permits or denies specific protocols
• Inbound or outbound
Why Use Access Lists?
– Manage IP traffic as network access grows.
– Filter packets as they pass through the router
Access List Applications
– Permit or deny packets moving through the router.
– Permit or deny vty access to or from the router.
– Without access lists, all packets could be transmitted onto all parts of your network.
Other Access List Uses

- Special handling for traffic based on packet tests
Outbound Access Lists
• If no access list statement matches, then discard the packet.

Interior Gateway Routing Protocol (IGRP)

2008-08-02T19:29:00.000-07:00

Interior Gateway Routing Protocol (IGRP) is a kind of IGP which is a distance-vector routing protocol invented by Cisco, used by routers to exchange routing data within an autonomous system.

– More scalable than RIP
– Sophisticated metric
– Multiple-path support

IGRP Composite Metric

– Bandwidth
– Delay
– Reliability
– Loading
– MTU

IGRP Unequal Multiple Paths

– Maximum 6 paths (default = 4)
– Within metric variance
– Next-hop router closer to destination

Configuring IGRP

IGRP Configuration Example

debug ip igrp transaction Command

Routing Information Protocol (RIP)

2008-08-01T19:55:00.000-07:00

The Routing Information Protocol (RIP) is a dynamic routing protocol used in local area networks. As such it is classified as an interior gateway protocol (IGP) using the distance-vector routing algorithm

- Maximum is 6 paths (default = 4).
- Hop-count metric selects the path.
- Routes update every 30 seconds.

RIP Configuration

- Selects participating attached networks.
- Requires a major classful network number

RIP Configuration Example

Verifying the Routing Protocol—RIP

Displaying the IP Routing Table

debug ip rip Command