Don’t Drink Too Much of the Kool-Aid First let me see a show of hands of how many people know what a vendor certification is? … A vendor certification is created by a computer equipment manufacturer, like a Cisco, Juniper Networks or Microsoft to help train their minions to operate …
Read More »Time–Based Access Control Lists
As you probably know, access control lists (ACLs in further text) are a means of providing firewall protection. Except the basic division on standard and extended ACLs, we distinguish between time-based, reflexive ACLs, turbo ACLs, and many other. The focus of this article are time-based ACLs, when should you use …
Read More »Router Stuck in ROMmon Mode
If you have ever experienced the ROMmon mode problem, you probably came across one of the following: configuration register forced the router to go to ROMmon mode during the boot process corrupt image (IOS) on Flash (indicated by bad_checksum message) router was unable to find the IOS (either on Flash …
Read More »Understanding Access Control Lists (ACL)
Defining an access control list may seem a challenging and complex task, especially to those that have just delved into the world of computer networking and network security. The aim of this article is to explain the role of access control lists and basic concepts used to understand them. The …
Read More »CCNA Notes: How to Study
Cisco Press has published several great books that cover the topics of the CCNA and CCENT in much detail.These books provide value to anyone looking to pass the exam, mainly because of the way they are structured. Cisco Press has designed the study books for those who have no experience …
Read More »CCNA Notes: Simple Network Management Protocol (SNMP) & Syslog
Notes: SNMP is an application layer protocol that provides a message format for communication between SNMP managers and agents. Information stored in the management information base (MIB) Cisco Prime is a SNMP manager Messages that send data are Get Messages Messages that write data are Set Messages SNMP traps are …
Read More »Understanding VLANs and Routed VLAN Interface in Cisco Switch
VLANs are virtual LANs that is used to segregate broadcast domains in a layer 2 domain. Logically, VLANs allows you to setup multiple switches in a same physical switch. VLANs are used to isolate different types of traffic in IP networks like voice, data, management, web, and so on. Similarly, …
Read More »Preparing a Cisco Certification – What you must do to succeed?
Amongst the many sought after certifications, the ones offered by Cisco are considered by hiring managers, recruiters, industry professionals and generally everybody in the IT industry as the most valuable certifications you can have on your resume. Whether it’s CCNA or higher-level Cisco certifications like the CCNP or CCIE, each …
Read More »FHRP or “First Hop Redundancy Protocols”
First Hop Redundancy Protocols (a.k.a. FHRP) are used to allow gateway redundancy. In this article, we cover the basics of this technology, with practical examples of configurations. I’m amazed at how the approach of the CCNA certification has changed since the time I took my test and entered the Cisco world …
Read More »Interview with Liz Burn, Juniper Networks Certification Program Director
The subject of Juniper Networks certifications is becoming more and more popular here on RouterFreak – just check the post You Don’t Need Cisco to be a Great Network Engineer and Junos Genius: your APP for Juniper Networks certifications. The question many of you have in mind is: why get a …
Read More »