Posts Tagged ‘CCNP’

Quite often I hear people reference the Native VLAN and they’re unsure what exactly they’re talking about. In the RFC standards “Native” is considered an “Untagged” VLAN on a port and that is the preferred terminology. So, this is really simple, “native” means “Untagged” because on each Cisco “Trunk” port you can have a different native VLANs on each Cisco “Trunk” port. Thus, the concept of a native VLAN isn’t always VLAN 1 it is just a convenience that VLAN 1 is the default VLAN on Cisco switches when they’re unpacked and that confuses most people. In reality, you won’t have an untagged port on a Cisco trunk because you’d rather have all inter-switch traffic tagged to prevent VLAN-hopping.

In a VTP environment I would recommend using passwords in your domains to prevent malicious users from screwing with your VTP domain. Just remember, if they have the domain name and a higher revision number, you can kiss your setup goodbye! Make sure the passwords are set on each switch and good luck.

If you’re wondering if you should use this I think you should. Having any traffic unauthenticated is just stupid and you’re asking for issues on your network with someone coming in and sniffing your traffic and discovering that you have hello messages with no or plain text authentication set. One shouldn’t have to explain the benefits; however, do understand that EIGRP has the advantage of using multiple keys in a ring that have expirations which helps rotate keys to prevent someone from getting a key that has been in use for years. OSPF does not have such a feature in IOS.

If you are working with the Nexus NX-OS and you want to redistribute static routes into EIGRP you MUST use route-maps. See below on how to use these in Nexus.

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Classful routing/networking is no valid into today’s CIDR (Classes Inter-Domain Routing) networks; however, it seems that people are still over using the classful terminology almost interchangeably. The concept of classes in network is obsolete and should no longer be used when referencing network subnets because classful routing has defined network ranges that make them classful and CIDR does not. Read the rest of this entry »

So as I study for the ASE I am reading the new HP Press books (that were purchased as bundle) for the test. Before this I was reading the older HP material that is in a wire bound book and was nothing more than HP copying crap from their website, print and wire bind it to a book. It was very dry, out of date, laced with grammatical errors and multiple configuration errors. Needless to say, the material is crap and I was excited to see that instead of trying to not be “Cisco Like” they joined the crowd and hired authors. Here is my review in comparison to the crap material that I read before… Read the rest of this entry »

HP vs Cisco Certifications

Being that I am a dual certification holder (HP and Cisco) I am going to weigh in on the Value of the certifications. Read the rest of this entry »

Core vs. Edge Routing Topology

There isn’t a lot of talk about this; however, there is a lot of training material that references this debate and makes recommendations for edge based routing. For those not familiar with the topic I am talking about “Campus LANs” and not ISP networks where you essentially have to push routing to the edge for some customers. In my article I am talking about Core vs Edge in the aspect of where we perform all of our routing in a “Campus LAN” Read the rest of this entry »

There are numerous occasions where we would like to utilize a more “human” name to view our physical switchport and router port connections; however, I find that most people don’t maintain these names/descriptions in a proper manner. While this configuration has no bearing on the operation of the switch it will create confusion for those who have to read through the documentation. Read the rest of this entry »

Just though I would put this out there for the world to read…use new network cables! If the cable doesn’t have a locking clasp you’re begging to have someone just brush by and jiggle it loose and then you’re troubleshooting an issue that looks complex when in reality all you have to is plug in a cable! ALWAYS USE NEW CABLES