Today I have stumbled upon an interesting technique from the Cisco Blog and Cisco Support Forum which is about defending an SQL injection using IPS, ASA or IOS firewall. I will concentrate on the ASA here to show you what you can do with this great device. Ofcourse what I will show works only for […]
Site to Site VPN with Dynamic Crypto Map
In this post I will talk about Hub-and-Spoke VPN with one dynamic and two static crypto-maps between Cisco routers. The scenario is as following: There is a central HQ site which will be the Hub of our VPN network and also two branch sites which will be the spokes in our VPN network (see diagram […]
Configuring AnyConnect WebVPN on Cisco Router (With Example Config)
In this post I will explain how to configure WEB VPN (or sometimes called SSL VPN) using the Anyconnect VPN client on a Cisco 870 router. However the configuration example and concept is the same for other Cisco router models as well. Web Based VPN has three Remote Access modes: Clientless – You connect to […]
Using USB Flash Drives in Cisco routers
A few days ago I have written a post about Booting a Cisco Router from USB Flash. Related to that post and since I got some questions about the subject, it seems appropriate to add some more information about how USB Drives can be managed and used in Cisco IOS routers. Some things to consider: […]
Upgrading Memory of Cisco ASA Firewall (5505,5510 etc)
After the introduction of Cisco ASA software version 8.3 a few years ago, the device’s memory requirements for low-end models have been doubled. Many firewall administrators have been discouraged from this move from Cisco because they had to upgrade their firewalls RAM memory in order to upgrade to the newest versions. Upgrading the memory not […]
I took the 642-524 SNAF Exam
Last week I took the Securing Networks with ASA Foundation (642-524) exam and passed with a score of 954/1000. It has been 3 years since the last time I took a Cisco exam because I had to renew my CCNA/CCNP/CCSP certifications which were going to expire this coming March. The good thing about recertification is […]
New Cisco ASA version 8.4 introduced
In January 2011 Cisco announced the newest Cisco ASA 5500 version 8.4. This release is coming after almost one year from the previous major release (version 8.3 was introduced in Feb-March 2010). You can upgrade to version 8.4 from any previous ASA version but you should know that if your current software release is older […]
Booting a Cisco IOS Router from a USB Flash Drive in Rommon Mode
Cisco routers typically store a copy of the device’s operating system (Cisco IOS) in their flash memory, and load this operating system image into RAM during the boot-up process. The flash memory of Cisco routers is usually internal or can be a removable flash card on higher end routers. However, it may happen that for […]
Characteristics of dynamic IP routing protocols
Below are some important characteristics of various Dynamic Routing Protocols that are used in Cisco IOS routers. RIPv2 * Distance Vector Protocol. * Suitable for small to medium networks. * Average convergence speed. * Supports VLSM. * Supports CIDR. * Standardized protocols (supports multi-vendor networks.) * Multicast address for updates: 224.0.0.9 * Administrative distance: 120. […]
Some Questions and Answers about the Cisco CCNA Exam
The CCNA certification exam is surrounded by many myths and mysteries that are maybe the result of the information overload and excessive literature, books and opinions out there. In this post I will try to dispel some of these myths and answer some questions that many people have about the test. NOTE: If you want […]
Important Points to Know About IPV6
We are slowly approaching the implementation of IPv6 in a mass scale and thus we must be ready to learn some significant differences over IPv4. Also, some IP addressing terms will start to appear with increasing frequency in our day to day work. So let’s see some notable concepts that you need to know about […]
How does VoIP work-Brief Overview
Just as in classical telephony, the voice signal is sent to the phone microphone handset in the form of an analog signal. An analog to digital converter transforms this signal into a digital one which is then encoded according to an audio format. There are different encoders for compression of a conversation with varying degrees […]
Cisco Training – Configuring Routing Information Protocol (RIP)
This routing protocol, also known as RIP, is a dynamic routing protocol which is utilized in both local area and wide area networks. It is classified as distance vector protocol. The metric to calculate the distance between a source and a destination network is hop count. The routing information protocol has had several revisions thus […]