Category Archives: Networking

Configuring OSPF with Multiple Areas

Posted on June 1, 2012 by Humair

In this lab, I use three Cisco 3725 routers [IOS 12.4(15)T10] to demonstrate how to setup OSPF with multiple Areas. Below is the network diagram for this lab.

Posted in Cisco, Labs, Networking, Protocols, Technology, Troubleshooting | Tagged Area, Areas, Cisco, Cisco 3725, Cisco 3725 router, Multiple Areas, Multiple OSPF Areas, OSPF, OSPF area, OSPF Areas, router | Leave a comment

Important IPv6 Addresses

Posted on May 1, 2012 by Humair

For easy reference, I’ve listed some important IPv6 address ranges below.

Posted in Networking, Protocols, Technology | Tagged important ipv4 addresses, important ipv6 addresses, ip, ip address, IPv4, ipv4 ip address, IPv6, ipv6 ip address, networking, special ipv4 addresses, special ipv6 ip addresses | Leave a comment

Networking: Blocking Access to a Website via Extended Access List [Video]

Posted on April 16, 2012 by Humair

This video demonstrates how to use an extended access list to prevent specific hosts from accessing a website. In this lab I use two Cisco 2811 routers [IOS 12.4(15)T1] and two Cisco 2950-24 switches [IOS 12.1(22)EA4].

Posted in Cisco, Labs, Networking, Technology | Tagged ACL, Cisco 2811, Cisco 2811 router, Cisco 2950, Cisco 2950-24, Cisco 2950-24 switch, Cisco switch, extended access list, Extended ACL, prevent hosts from accessing a website, prevent specific hosts from accessing a website, router | Leave a comment

Networking: Spanning Tree Protocol Basics [Video]

Posted on April 15, 2012 by Humair

This video covers some of the basics of how Spanning Tree Protocol (STP) works in a network. To learn more about Spanning Tree Protocol see some of my prior blogs on STP.

Posted in Networking, Protocols, Technology | Tagged Loop Avoidance, loop prevention, network loops, Spanning Tree Protocol, STP | 1 Comment

Coding a XenServer Client in Python – Monitoring Multiple VMs via Multiple Threads

Posted on March 30, 2012 by Humair

In some prior blogs I had written about developing an ESXi client in Java which could connect to a VMware ESXi server and perform some management tasks. In this blog, I will describe developing a Cirtrix XenServer Client in Python … Continue reading →

Posted in Networking, Programming Languages, Protocols, Python, Technology, Virtualization and Cloud Computing | Tagged Citrix, Citrix Xen, Citrix Xen API, Citrix XenAPI, Citrix XenServer, HueXenClient, ICMP, ICMP packets, Network Monitoring, ping, PMW, port, ports, PyDev, PyDev plug-in, Python, Python megawidgets, Python megawidgets library, python pmw, thread, threads, Tkinter, Tkinter GUI library, VM Monitoring, VM Network Monitoring, Xen, XenAP, XenCenter, XenClient, XenServer, XenServer 6.0, XenServer pool | Leave a comment

EIGRP – Best Path Selection

Posted on March 27, 2012 by Humair

By default EIGRP uses bandwidth and delay of the line to determine the best path to a remote network. However, if desired, EIGRP can use a composite of four metrics: bandwidth, delay, reliability, and load. Maximum transmission unit (MTU) is … Continue reading →

Posted in Cisco, Labs, Networking, Protocols | Tagged bandwidth, Cisco, Cisco 3725, Cisco 3725 router, Cisco 3725 routers, delay, delay of the line, EIGRP, EIGRP calculation, eigrp load balancing, Enhanced Interior Gateway Routing Protocol, equal cost load balancing, load balancing, router, routing table, topology table | Leave a comment

Setting-up Basic iBGP and eBGP on Cisco Routers

Posted on March 15, 2012 by Humair

The Border Gateway Protocol (BGP) is a protocol used to make core routing decisions on the Internet. BGP is commonly mislabeled or referred to as an IP routing protocol. However, it is not a routing protocol; rather, it is a … Continue reading →

Posted in Cisco, Networking, Protocols, Technology | Tagged AS, Autonomous Number, Autonomous Numbers, BGP, BGP table, Border Gateway Protocol, Cisco, Cisco 3725, Cisco 3725 router, eBGP, established, established state, External BGP, iBGP, Internal BGP, Multihomed, neighbor, neighbor relationship, Neighbors, ping, prefxes, redistribute connected, redistribute static, redistribution of static and connected routes into BGP, show ip bgp, show ip bgp summary, state | Leave a comment

Single/Dual and Multihomed Connections

Posted on March 12, 2012 by Humair

Network engineers will sometimes speak of connections to their ISP(s) in terms of single homed, dual homed, single multihomed, and dual multihomed. Here is a breakdown and clarification of what this terminology means: – Single Homed (1 link per ISP, … Continue reading →

Posted in Networking, Protocols, Technology | Tagged BGP, Border Gateway Protocol, connection redundancy, dual homed, dual multihomed, internet redundancy, isp, isp redundancy, redundancy, single homed, single multihomed | 1 Comment

EIGRP and OSPF Redistribution on Cisco Routers

Posted on February 7, 2012 by Humair

This was a quick lab I threw together which I thought was pretty cool. In this lab I use five Cisco 3725 routers [IOS 12.4(15)T10] in which I have two groups of routers each on a different subnet and running … Continue reading →

Posted in Cisco, Labs, Networking, Protocols, Technology | Tagged Cisco, Cisco 3725, Cisco 3725 router, cisco router, EIGRP and OSPF Redistribution, EIGRP Redistribution, EIRGP, OSPF, Redistribution, router | Leave a comment

Setup and Troubleshoot EIGRP

Posted on February 2, 2012 by Humair

I discussed Enhanced Interior Gateway Routing Protocol (EIGRP) briefly in a prior blog, Load Balancing with EIGRP, however, in this lab I use two Cisco 3725 routers [IOS 12.4(15)T10] to demonstrate how to configure EIGRP; additionally, I’ll discuss some useful … Continue reading →

Posted in Cisco, Labs, Networking, Protocols, Technology, Troubleshooting | Tagged Cisco, Cisco 3725, Cisco 3725 router, Cisco 3725 routers, dynamic routing, EIGRP, Enhanced Interior Gateway Routing Protocol, router | Leave a comment