In this replay, we are discussing the Non-Technical Side of IT. Guest Speakers:Simone B.Kierra @iamkierradKim @lipstickandtechMary @Girasol_MaryCharmain @lovee_charmsTerrence @bmoreopensourceBrittney @bossy_brittObi @ProgrammerPapi

In the Replay, we discuss tips for choosing which technologies you should learn and get certified in.

On this episode I am discussing what a network engineer is, what we do and an overview of what a typical day may look like. I also discuss some differences between the Network+ and CCNA and answer a listener question from Instagram. Show Notes are available at https://www.ccieby30.com/show-notes

CVST-4/25/10 – Join Cisco Certified expert John Friedrich as he gives out weekly tips involving Cisco Voice and Security related concepts! Visit dynacomp.com for the show notes! This podcast is produced by TechJives.net – Chris Popeadmin による

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 drastically different bandwidth (a frame-relay hop has the same cost as a 10-gig-ethernet in RIPng). Each router m…

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 understand. At first glance they appear simple. You just manually configure which next-hop to go to for each subnet…

In this tutorial I will share with you step by step how to deploy a rogue wcs server and sniff an RRM packet to own a Cisco Wireless Network.George Stefanick Jr による

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 not have solved this problem. The email download would simply have been faster, but the VOIP call would still…

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 replacing one layer in the stack, most applications and most layer-2 network devices will continue to function. IPv6…

There is more to the OTAP issue that Cisco didn't tell you ! Even when OTAP is disabled the WLAN controller information is still being transmitted.George Stefanick Jr による

Did you know when you associate to an access point your wireless NIC reports to the OS a 4201 code? Or, when your wireless NIC loses connectivity it reports a 4202 code? In this nugget, we will review the System Event Log for a wireless NIC. More specifically the 4201 and 4202 event code. I will also reproduce these event code in our lab.... Just a…

This nugget covers DHCP 43 configuration for a Cisco LWAPP deployment using a Windows Server 2003. You dont want to miss this nugget!George Stefanick Jr による

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 need. Different IOS "packages" have different features. For example, the "LAN base" package includes basic…

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 to many production networks, where maintaing comments and old revisions of ACL's is a requirement. We also s…

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 network. It's important to understand that most IOS routers have relatively slow CPU's. An IOS router is fine a…

Learn how to leverage Cisco's AP Group functionality in your enterprise to enhance your network by shaping the broadcast domains of your wireless clients while keeping intact a common SSID!! I will show you the steps, start to finish, how to configure Cisco AP Group!George Stefanick Jr による

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 subnet can use the virtual IP for their default route. This way if one router goes down the redundant router wil…

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 convergence time of the historic 802.1d spanning-tree protocol. Rapid spanning tree replaces timers wit…

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 link with twice the bandwidth. In addition to increased bandwidth, etherchannels fail over in a fraction of…

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 flooding. VTP can eliminate outages thanks to the uniform VLAN configuration. But it can also cause outages if inco…

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 information. ISL is an older Cisco-proprietary trunking protocol. Newer switches do not even support ISL. Newer…

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 bpduguard to disable portfast-enabled ports where someone erroneously plugs in a switch. Using errdisable timeout…

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 purposes (IT, accounting, network management) on one physical switch. This saves money and cabling while decr…

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 packet onto a physical medium. Examples of physical mediums include fiber, twisted pair, coax, radio wav…

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 autonomous system to make intelligent routing decisions regarding which of multiple paths to take to send traf…

We filter BGP routes in 4 different ways.Darrell Root による

We put together what we learned about eBGP, iBGP, and OSPF.Darrell Root による

An iBGP example with 1 autonomous system with 3 routers.Darrell Root による

An eBGP example with 3 autonomous systems with 1 router each.Darrell Root による

An introduction to BGP theory.Darrell Root による

OSPF routes should be filtered or summarized at area border routers.Darrell Root による

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 as RIP distribute lists. In fact, using distribute-lists within an OSPF area is dangerous.…

OSPF totally stubby areas and not-so-stubby areas are ways to improve OSPF scalability. But they can be very confusing.Darrell Root による

We cover OSPF stub areas and neighbor synchronization.Darrell Root による

We redistribute from RIPv2 into OSPF and introduce autonomous system boundry summary LSAs and external summary LSAs.Darrell Root による

We introduce multiple OSPF areas and network summary LSA's.Darrell Root による

We show a single area OSPF network and go into router and network link state advertisements (LSA's) in detail.Darrell Root による

A brief tutorial on Dijkstra's Shortest Path First Algorithm. This algorithm is used by most link state routing protocols, including OSPF and IS-IS.Darrell Root による

RIP version 2 includes subnet information in the route advertisement. It also improves efficiency by multicasting to RIPv2 routers instead of broadcasting to all hosts.Darrell Root による

If you run two different routing protocols in two different parts of your network, you need to redistribute routes between the two routing protocols. This session is an introduction to route redistribution by example. In production you must be cautious about route redistribution because the route metric is not converted in a meaningful manner. This…

"Ships in the night" routing refers to two routing protocols which do not interact with each other. We can migrate from one routing protocol to a more believable one by simply turning on the new protocol then turning off the old protocol. Bug be careful to turn the new protocol on in the entire routing domain before turning off the old protocol.…

IGRP is a Cisco-proprietary routing protocol. It is a classful distance vector protocol with a metric based on bandwidth and delay. This is superior to RIP, whose metric is based on hop-count. IGRP's classfulness makes it a bad choice for new deployments, but its advanced metric is worth study.Darrell Root による

RIP distribute lists deny specific route advertisements. RIP offset-lists increase the metric (hopcount) for specific route advertisements.Darrell Root による

RIP version 1 route advertisements do not include a field for the netmask. This means receiving routers have to gess the netmask based on whatever information they have available. That includes the "natural" netmask of that classful network. That also includes the receiving routers own configuration. This means that variable length subnets and disc…

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.Darrell Root による

Routing protocols (and static routing) update the route table. The route table is used to forward packets. Cisco Express Forwarding (CEF) is a special route table optimized to forward packets more efficiently.Darrell Root による

We cable and configure ethernet and synchronous serial point-to-point links. In the next session these will be the "legs" of our triangle.Darrell Root による

Routers route packets based on the destination IP address: a 32-bit number included in the header of every IP packet. Historically, "large" sites were allocated IP address blocks starting with 0 (binary). Medium sites were allocated address blocks starting with the bits 10. "Small" sites were allocated address blocks starting with the bits 110.…

Every network engineer needs to be able to deal with a router with an unknown password. Whether you are taking over a site where the previous engineer was "hit by a bus", or scrounging routers from the storage closet, good network engineers can deal with routers with unknown passwords.Darrell Root による

You can best take advantage of the Cisco training podcast series by getting routers and following along. First you need to scrounge or buy routers and cables. This episode helps you decide what to get. This episode also explains how to access the console.Darrell Root による