Information Technology Blog (Archive)

Hello folks! You might be surprised that I suddenly decided to make a post in this blog. This is because I've worked with a packet tracer lab just recently as part of my CCENT class. Yes I had a CCENT class. But there's only one student. He was an aspiring network engineer, planning a career shift and I have a fair share of experience and knowledge gained from the past three years of working in this field. So I thought why not? I can share what I know and was hopeful that I could inspire another to learn the world of networking. After all I had such a fun ride, networking is hard, but fun!  So for the final assessment I had to let him see the big picture. What is Routing really? What is Switching? What is the significance of IP? What is branch and enterprise networking?  I taught him the basic essentials. I showed him my own technique in IP subnetting. I kept on telling him to see the pattern in everything because that's how I got it. I explained to him where Routi...

The purpose of this lab is to present the two of the four OSPF network types that you can use with Frame Relay: Point-to-point and Multipoint and some issues you may encounter because mainly, OSPF works differently on each type. Wendell Odom in his book, CCNP Route Official Certification Guide outlined the three important points when using OSPF over Frame Relay which is basically the inspiration of this lab.  To get started, paste the base configuration below for each router: R1 hostname R1 ! interface Loopback0  ip address 10.2.1.1 255.255.255.0 ! interface Serial0/0  no ip address  encapsulation frame-relay  no shutdown ! interface Serial0/0.2 point-to-point  ip address 10.2.12.1 255.255.255.0 ! interface Serial0/0.3 point-to-point  ip address 10.2.13.1 255.255.255.0 ! interface Serial0/0.45 multipoint  ip address 10.2.145.1 255.255.255.0 ! router ospf 1  log-adjacency-changes  network 10.2.0.0 0.0.255.255 area 0 R2 hostname R2 ! inter...

IPv6 is one of those CCNA topics I was not confident explaining to someone. I was intimidated by its new features and whenever I see those series of 32 hexadecimal numbers, I get really uneasy. So I decided to put an end to it by getting in the bottom of things with IPv6. Now I am no longer intimidated and I am glad to finally get this off of my chest. ;) So here, I want to share my study notes on IPv6. Some facts about IPv6 - 128 bit address; 32 hexadecimal numbers; 8 quartets of 4 hex digits - IPsec is required on IPv6 hosts - improvement of IPv6 header: no more recalculation of checksum for every packet sent & includes flow label for easy identifaction of packets sent over the same TCP/UDP connection - strategic IPv6 address assignment has been adapted from IPv4 and this process is being handled by Internet Corporation for Assigned Network Numbers (ICANN) - no more broadcast (uses multicast, unicast and anycast) Subnetting A company was assigned by ISP with address 2340:1111:AAA...

Using virtualization, we can try executing a basic Asterisk dialplan and make a SIP call between two Windows machines. Requirements 1. Fully setup Asterisk call manager on your Linux Machine with configuration all set to default 2. Softphone applications (3CX) on Windows 7 host and Windows XP guest 3. Enabled Microsoft Loopback Adapter on Windows 7 host 4. Knowledge on basic networking (LAN connectivity) Setup LAN Connectivity All three machines must be on the same subnet. This is the IP configuration I used in this scenario: Windows 7 host [Microsft Loopback Adapter] IP Address: 172.30.100.13 Subnet mask: 255.255.255.0 Windows XP guest IP address: 172.30.100.14 Subnet mask: 255.255.255.0 Ubuntu guest IP address: 172.30.100.20 Subnet mask: 255.255.255.0 Now we need to test our virtualized LAN connectivity. All machines must be able to ping each other. This is possible using the Microsoft Loopack Adapter on our host machine. Setup Asterisk This is the default script for our asterisk.con...

I have always dreamed of this day when I can finally post here as a CCNA. For 3 months (November to January), I've focused all my energy in studying for this exam and at 12PM of March 06, 2012, all of it finally paid off. It wasn't really planned that I will take the exam on that date. A week before, I have hopes of finally taking the exam but I only knew when I'll be taking the exam the day before the exam itself when my parents finally got the money they loaned. So for a month, I just waited. Good thing I have my notes with me and the CCNA Labs for light reviewing. On the day of the exam, I have to go to the testing center to have my exam scheduled on that same day. I travelled all the way from Pasay, Metro Manila to Sampaloc, Manila. At the testing center, the staff was having problem including my discount voucher from Cisco Networking Academy and it was because I haven't entered my Academy Connection ID in my PearsonVUE account. I resolved the issue, had my photo t...

I am doing the lab,  CCNA Labs - Cisco for the Real World in   GNS3 and as of now I have reached the end of Phase 3 and I can say that this lab is amazing. I've configured familiar things which are on the CCNA scope like VLANS and Trunking, NAT, Static route. I also configured EtherChannel which is discussed in CCNA but I don't remember having configured one during labs on my Cisco Networking Academy class few years back. There are also major topics which are not in the CCNA scope like Inter-VLAN with L3 Switching and (drum roll) ... VPN configuration! In this lab, I am to setup the Branch Office network which has different VLANS, runs VOIP, with two APs one for Public and one for Private. The Private AP is connected to the internal private network while the Public AP can only connect to the Internet. There is a SERVER which can be accessed from the Internet and hosts should be able to access the Internet by passing through NAT. Then the Branch Office must be able to conn...

Wow, I am not aware it's almost a month since my last post here. I've been busy with other stuffs, sending out applications, getting interviewed, etc. I'm counting down the days towards graduation and hopefully my CCNA exam. After that, I think I can really focus all my energy in finding that networking job. I don't usually write a post unless I have an inspiration for it and for this post, I got the inspiration from the 8th nugget of  CCNA Labs – Cisco for the Real World.  I am going to setup Inter-VLAN not with router-on-a-stick but with Layer 3 switching.  This is the topology: The switches in the topology are actually 3725 routers with a 16-port EtherSwitch module. This is how you emulate switches in GNS3. For the IOS, I am using c3725-advipservicesk9-mz.124-3 which I have been using in my labs. I changed the icon so that I can really feel that I am configuring switches and not routers. There are 3 VLANS:  VLAN 10 on SW2, VLAN 20 on SW3 while VLAN 30 i...