What do they call you?

My 5-year old son Josh recently finished preschool.  He will be starting Kindergarten in August at Discovery Charter School, where 7-year old Mikey recently finished 1st grade.  The school is holding a 3-week summer school session where the kids can go to school for 4-hours a day, 4-days a week.  Returning students were invited to attend.  The school invited Josh to attend also.  Tonight as I was putting him in bed, I said to him:

“I wonder what the school calls you.  You’ve finished Preschool but you haven’t started Kindergarten yet.”

Without missing a beat, he said “I think they call me Josh.”

I sure love this kid. 🙂

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Michael H. Cox, CCNA

CCNA

Its official! I passed 640-816 ICND2 exam today so I am now officially a Cisco Certified Network Associate, more commonly called CCNA.  This was a hard exam.  I started working on ICND1 back in April or May.  Before then, I had never really worked on a Cisco device.  As I mentioned on my July 5 blog post “Oh Cisco“, I have wanted to work with Cisco devices for years, but never had.  I have started installing some Cisco gear at work.  I think the key to passing was the Cisco Notes that I typed up and posted here.  A great way to study a topic.  I printed these up and studied them at the testing center why I was waiting to sign in.

I will not be posting Cisco Notes as often as I have over the last few days, but if I find something worth while, I will post it.  In a year or so, I will be working to get my CCNA Security and will definitely start posting again then.

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OSPF notes

This is part of the Cisco Notes series on Mike’s World News.

Open Shortest Path First (OSPF) is a Link State Routing protocol.

It is a Classless protocol, so it supports Variable Length Subnet Masks (VLSM) and CIDR.

OSPF does not use Split Horizon nor does it use Auto Summarization.

It uses Dijkstra SPF algorithm.

Uses Multicast address 224.0.0.5 for updates (as well as 224.0.0.6).

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RIP v1 and RIP v2 notes

This is part of the Cisco Notes series on Mike’s World News.

There are 2 versions of RIP that IPv4 networks can use as a Routing Protocol, namely RIP version 1 and RIP version 2.

Both RIP v1 and v2 are Distance Vector protocols.  This means that the way they advertise routes is based on how far away in the routers are from each other.  If, for example, to get from Router 1 to Router 4, there are are ways two get there, both RIP v1 and v2 will count how many routers are each way and go the way with the fewest routers. This is referred to as a Hop Count.

See image below:
In this example, Router 1 can communicate with Router 4 either by talking to the router directly (1 Hop), or by talking to Router 2. then 3, and then finally 4 (3 Hops).  RIP v1 and RIP v2, regardless of the speeds  of the connections will always go from Router 1 to Router 4.

Every 30-seconds, the full routing table is sent to all other routers.  RIP v1 does this as a broadcast (255.255.255.255) and RIP v2 does this as a multicast to 224.0.0.9.

The Administrative Distance of RIP is 120.

RIP will load balance equal cost links.  So, in the example above, traffic from Router 1 to Router 3 will be load balanced, with half going via Router 2 and half going via Router 4.  By default, it will load balance up to 4 paths.

RIP uses Split Horizon, which prevents a Router update across the same interface that received it.

By default, RIP wil use Auto Summerization.

RIP v1 is a Classful Routing Protocol.  It does not, therefore, support Variably Length Subnet Masks (VLSM) or CIDR.

RIP v2 does support both VLSM and CIDR.

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Frame-Relay Notes

This is part of the Cisco Notes series on Mike’s World News.

Frame Relay is a Common WAN protocol which exists at layer 2 only, therefore frames are transmitted. The frames are a variable sized.

can transmit upto 1.54 mb.

Your router is the DTE. They receive the clocking speed from the DCE, inside the frame-relay cloud.
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CIDR Notes

This is part of the Cisco Notes series on Mike’s World News.

This post refers to the Subnet Cheat Sheet published earlier today and is some notes about CIDR and subnetting.

CIDR stands for Classless Inter-Domain Routing and is what replaced the Old Class A, B, and C networks. It is an abbreviation of sorts for the subnet mask. Rather than writing something like:

IP Address of 192.168.2.5 with a subnet mask of 255.255.255.0
you can write:
192.168.2.5/24.
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Subnet Cheat Sheet

This is part of the Cisco Notes series on Mike’s World News.

I think one of the most important things to write down once you get into the testing center during the Cisco tutorial is your CIDR notation, with the # of hosts, and the full Subnet Mask.  I would go from /22 – /30, although that is my personal preference. 
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Cisco Access Control Lists Notes

This is part of the Cisco Notes series on Mike’s World News

Standard Access Control Lists (ACLs) are 1-99 and 1300-1999.
Extended ACLs are 100-199 and 2000-2699.

Standard ACLs are typically placed close to the destination.
Extended ACLs are typically placed close to the source.
I remember this as: SD/ES
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