RIP version 1 is a classful routing protocol. We cover the RIP packet format and configuration. We see examples of split horizon and triggered updates using the RIP debug commands.

IPv6 RIPng dynamic routing

Mar 14th, 2010

The linked video demonstrates RIPng, our first dynamic routing protocol for IPv6. This is a simple but inefficient routing protocol. The metric is based on number of router hops, with no provision for differentiating between links with drasti

IPv6 Static Routing

Nov 2nd, 2009

In this hands-on exercise, we configure IPv6 addresses on 3 routers in a triangle. Then we configure IPv6 static routes to allow the 6 IPv6 subnets (3 loopback, 3 P2P links) to be accessible on all 3 routers.Static routes are easy to understan

The need for QOS versus Net Neutrality

Sep 27th, 2009

In 2003, I made a VOIP call from home while downloading a large email attachment. The DSL line saturated and my audio quality became horrible while VOIP packets (and email packets) were being dropped. Doubling the bandwidth to my home would n

IPv6 theory

Sep 20th, 2009

The linked video introduces IPv6 theory. IPv6 is the 128-bit address replacement for IPv4. The Internet is expected to run out of it's 4-billion IPv4 addresses in 2012. IPv6 will replace IPv4 at the network-layer of the OSI stack. By replac

IOS Version Selection Tactics

May 31st, 2009

The linked video provides guidance for optimal IOS version selection.The large number of IOS versions makes choosing the best version for your router or switch difficult. You must pick the most reliable version which includes the features you

IOS Access Control Lists

Mar 24th, 2009

In this video demonstration, we show an example of writing IOS Access Control Lists (ACL's) on a home router. We use the revision control system (RCS) to maintain the master ACL file and push the ACL's to the router via TFTP. This is similar

IOS DHCP and NAT

Mar 23rd, 2009

IOS routers can act as DHCP clients and DHCP servers. They can also function as Network Address Translation (NAT) devices. In this video we show a demonstration using a 2621 as a DHCP client, server, and NAT translation device for my home net

Hot Standby Router Protocol

Mar 22nd, 2009

In this episode we show a video demonstration of the hot standby router protocol. This is a Cisco proprietary redundancy protocol. The purpose is to allow two routers to share one virtual IP address on an access subnet/vlan. Hosts on the sub

Rapid Spanning Tree 802.1w

Mar 8th, 2009

This video demonstrates layer-2 convergence in less than 2 seconds thanks to rapid spanning-tree.Rapid per-vlan spanning-tree is configured with "spanning-tree mode rapid-pvst".The rapid spanning tree protocol, 802.1w, is the answer to the slow

Etherchannels and the port aggregation protocol

Mar 3rd, 2009

When you have two different links between the same two switches, normally spanning tree will forward on one and block on the other. This means half of your bandwidth is sitting idle. An etherchannel is a way to bind two links into one logical

VTP Vlan Trunking Protocol

Mar 1st, 2009

VTP is the VLAN trunking protocol. It's used to disseminate uniform vlan information between switches over 802.1q or ISL trunks. It can also "prune" vlans, dynamically removing unneeded VLANs from trunks. This decreases unneeded frame floodi

802.1q and ISL trunks

Feb 24th, 2009

Switches can have multiple vlans. When we connect switches together we use 802.1q trunks (or older ISL trunks) to run multiple vlans over one physical link. With either trunking protocol, a tag is added to the ethernet frame with the vlan inf

Intermediate spanning tree

Feb 23rd, 2009

We cover intermediate spanning tree concepts. The importance of specifying your root bridge and backup root bridge with spanning-tree priority. Using portfast to allow host ports to start forwarding without waiting for 30 seconds. Using bpdu

VLANs and spanning tree

Jan 31st, 2009

VLANs are a feature of ethernet switches which makes them act like multiple "virtual switches". Each VLAN is a separate broadcast domain and could be configured with a separate subnet. That way could could have separate subnets for separate p

How ARP and Ethernet Work

Jan 25th, 2009

So far we've talked about how IPv4 encodes data into a packet, and how routers learn which direction to forward those IPv4 packets based on the destination IP address and the route table.But in the end, routers and hosts need to encode the IPv4

BGP route selection with MEDs

May 29th, 2008

In BGP, MED stands for Multi Exit Discriminator. It is a well-known optional attribute which allows one autonomous system to inject it's IGP route metrics into its BGP advertisements to another BGP autonomous system. This allows the second au

BGP route filtering

Apr 11th, 2008

We filter BGP routes in 4 different ways.

eBGP and iBGP

Mar 22nd, 2008

We put together what we learned about eBGP, iBGP, and OSPF.

iBGP

Mar 20th, 2008

An iBGP example with 1 autonomous system with 3 routers.

eBGP

Mar 19th, 2008

An eBGP example with 3 autonomous systems with 1 router each.

Introduction to BGP theory

Mar 15th, 2008

An introduction to BGP theory.

OSPF route filtering and area border routers

Oct 21st, 2007

OSPF routes should be filtered or summarized at area border routers.

OSPF distribute-list problems

Oct 7th, 2007

OSPF's fundamental design is that all routers in an area have the same exact view of the network topology. This is fundamentally incompatible with filtering routes within an area. As a result OSPF distribute lists do not have the same effect