Networking, Routers and Routing

1. Routers and routing protocols

Networks: LANs and WANs at OSI layers 1 and 2, routing at layer 3, interfaces between LANs and WANs

Router characteristics and operating systems: physical characteristics, components, interfaces, management port, need for an OS, user interface (UI), UI modes, connect to a router using terminal emulation software (eg HyperTerminal) command line interface (CLI), web based management, get information about remote devices, use, disconnect and suspend telnet, connectivity tests

Router configuration: command line modes, name the router, set passwords, examine router status, configure serial and Ethernet interface/s, save the configuration, set up host name resolutions, configure host tables, backup the configuration, document the router set up, troubleshoot IP connectivity, discover and connect to neighbouring routers, gather information about neighbours, implement, monitor and maintain neighbour links, create a network map

Routing protocols: purpose, classes (distance vector, link-state), route determination, configure, verify and troubleshoot routing (static, dynamic, default), autonomous systems, compare interior and exterior gateway protocols (IGP, EGP), Distance vector (protocol updates, OSI terminology, prevent count to infinity, eliminate routing loops with split horizon, route poisoning, avoid routing loops with triggered updates, prevent routing loops with hold-down timers), Routing Information Protocol (routing process, configure RIP, verify and troubleshoot RIP, RIP updates, prevent routing updates through an interface, balance loads across multiple paths, static routes), Interior Gateway Routing Protocol (features, metrics, routes, stability, configure IGRP, migrate RIP to IGRP, verify and troubleshoot IGRP.)

2. Router operating system management

Router boot process: manage the operating system and boot process, eg (boot sequence, verification, power-on boot sequence, locate and load OS, determine and configure the boot process, troubleshoot OS boot failure, file system management, OS naming conventions, router configuration files (load, save using TFTP), copy-and-paste configuration files, backup, restore and upgrade OS image with TFTP and XModem.)

3. TCP/IP suite and diagnostics

Internet Control Message Protocol: error (reporting, correction), message delivery, unreachable networks, ping, excessively long routes, echo messages, destination unreachable message

TCP/IP suite control messages: redirect/change requests, clock synchronisation, transit time estimation, information request and reply message formats, address mask requirements, router discovery message, router solicitation message, congestion and flow control messages

Network Testing: structured approach, test by OSI layers, layer 1 using indicator lights, layer 3 using ping, layer 7 using telnet, Router diagnostics (routing table, default gateway/route, Layer 2 and 3 addresses, administrative distance, route metric, next hop, most recent route update, multiple paths to destination, interface status, neighbours advertising on layer 2, using traceroute, serial controllers status, using debug)

Layer 4 Protocols: TCP Operation (synchronisation process, 3-way handshake, denial-of service attacks, windowing, sequencing numbers, positive acknowledgement), UDP operation

Transport Layer Ports: multiple conversations between hosts, ports for (services, clients), well known ports numbers, clarify the difference between (MAC addresses, IP addresses, and ports)

4. Access Control Lists

Access Control Lists (ACLs): describe how they work, how to create, wildcards, changing an ACL, verifying, standard and extended, named ACLs, where to place ACLs, firewalls, restricting virtual terminal access.