Tag: IP

/31 subnet in point-to-point links. Is that possible?

subnet /31

Ok, this is strange! At least this was my first reaction when I saw that in one of my CCIE labs that I am trying to resolve all the links between routers are addresses with a subnet /31.

Isn’t that weird that something like this you see for this first time after couple of years in networking. For me it was. It blow my mind out. I asked my more experienced networking colleagues later but for them it seemed new too. They said at first: Ok men, that’s not possible!

Well, try to type it on router interface and you will se that it is possible. It strange for sure, but it’s possible. Router OS (Cisco IOS in this case) will try to be sure that you will use this kind of subneting only for Point-to-point links. That’s why it will issue a warning message if you apply this subnet mask on an Ethernet interface. For serial it will go without the warning.

The idea behind this is of course simple if you put it this way:

Don’t use 192.168.1.0/24 on work LAN

This story will be a turning point for my blog future starting with a change in writing methods and changing those methods to a more causal fashion.

INTRO

Flame VirusFor now all my text here where somehow depersonalized and tech oriented in a way that it was all written like in some book. User manual to me concise. Maybe this is the main reason that now when I got back to revise some parts of the texts there was an impression that those text are very boring. There is something missing inside them, maybe me?
Of course, I didn’t start to write this blog two years ago because there was a huge need for someone new to write about old networking stories about protocols and networking standards. I did start to write because I was young enthusiastic freshy networker who was in his all day job searching, part-time Cisco teaching and CCNP studying period.
That was actually not job free time for me, but it was intense and fulfilling time. Having some experience with web before and now spending whole days with my head inside Cisco Press books it was somehow natural to start a blog. Yes I know, everybody wants to write something on the web, but that is the main reason for this post, I you wondered what is this all about. I can now finally say that if I did not give up writing this blog until now then it’s the real proof that there is actually somebody reading it and that I can finally consider myself a networking blogger but more that all an networking geek. Jup, that’s right, there are people who are not ashamed of being geeky technicians.

What is my IP address

Online visitors usually want to know their IP address for certain reasons like: for game playing purpose, technical support, remote connection and proxy detection etc. Moreover, they can also check is their address changed or still there are using their personal e-mail server. If you want to gallop your personal e-mail or web server then static IP address will best for you.

IP Address – Internet Protocol address: Basic about IPv4

An IP address (Internet Protocol address) is actually a numerical tag that is assigned to each participating device over the network either a computer or a printer. These devices are attached via networking using internet protocols for their communication.

Two main functions of an IP address are given under:

  1. Identifying a host or a network interface
  2. allocating addresses

UDP – User Datagram Protocol

Let’s see what is UDP – User Datagram Protocol. Inside the computer world, term “networking” is denoted to the physical joining of two machines for different purposes like communication and data distribution. But mesh of this hardware and computer’s software can communicated with each other with the help of specially designed protocols. Moreover, computer networks can be categorized on the basis of such communication languages (protocols) used by a network.