DNSSEC (DNS Security Extensions), a more secure DNS protocol is to be implemented on May 5th. With the rise of DNS Poisoning and Man-in-the-Middle attacks rising, the Domain Name System will be going to a secure version of DNS next month. The changes will add digital signatures to the DNS protocol. This will reduce the […]
Routing Protocols Overview
There are different techniques and methods for maintaining accurate routing information, thus different types of routing protocols were invented over the years. The following post is intended to offer you an overview of the different types of routing protocols currently available. Distance Vector / Link State The above terms refer to the algorithms that govern […]
Routing Redistribution on Cisco Routers (Cheat Sheet)
In order for two Layer 3 devices (routers or layer 3 switches) to be able to exchange routing information, it is necessary to use the same routing protocol, such as RIP, EIGRP, OSPF, BGP, etc. Different routing protocols, or protocols configured differently (eg different EIGRP autonomous system) do not exchange information. However, when a device […]
This is the new domain home for Cisco-Tips
Hello there, this is Harris Andrea. Today I have redirected my older blog Cisco-Tips.com to its new domain home which is the website you are viewing now (NetworksTraining.com). Please update your bookmarks accordingly. I have configured a permanent 301 domain redirect (using .htaccess file) for the whole cisco-tips.com website and I have moved the old […]
How to Recover a preshared key of IPSEC VPN on Cisco ASA
One of the ways to configure authentication between two Cisco ASA firewalls having a site-to-site IPSec VPN tunnel between them is to configure a pre-shared key under the tunnel group attributes. This is actually the most common implementation of IPSEC lan-to-lan authentication that you will find in most real life networks. The pre-shared key must […]
Understanding the Transport Layer and Port Numbers CCNA Tutorial
This is another CCNA exam preparation tutorial about the Transport Layer of the TCP/IP suite. Understanding the purpose and functionality of the Transport Layer (Layer 4 in the OSI model) is fundamental for understanding how data is transmitted in network environments. When preparing for the Cisco CCNA 200-301 exam, you need to have strong knowledge […]
DoS Protection on Cisco 7600 Routers and IP Networks
The Cisco 7600 router is in my opinion one of the most versatile High End routing machines on the planet!! It is one of my favorite networking devices. If you take a look at Cisco website under the Routers Product Category, you will notice that the 7600 can be used in Data Centers, in Service […]
Configure Cisco ASA 5505 to allow Remote Desktop access from Internet
A very popular scenario for small networks is to have a Cisco ASA 5505 as border firewall connecting the LAN to the Internet. Administrators in such networks are usually encountered with requests from their users that are not very security conscious. Such a request could be to allow Remote Desktop (RDP) access from the Internet […]
Cisco ASA version 8.3 is here
On March 8, 2010 Cisco announced the newest Cisco ASA 5500 firewall software version 8.3. This is a release with the most radical changes compared to the previous releases since version 7.x. The most important change regarding configuration is the way Network Address Translation (NAT) is implemented. Also, another big change regarding hardware is that […]
Comparison Between Cisco ASA WebVPN Technologies
Cisco ASA supports two major WebVPN modes: Clientless WebVPN and Anyconnect WebVPN. Let’s see the differences between the two WebVPN modes and I’m sure you will understand why the AnyConnect mode is much better in my opinion. Clientless WebVPN does not require any VPN client to be installed on user’s computer. It uses a normal […]
Overview of Cisco ASA VPN Technologies and Types
Cisco supports several types of VPN implementations on the ASA but they are generally categorized as either “IPSec Based VPNs” or “SSL Based VPNs“. The first category uses the IPSec protocol for secure communications while the second category uses SSL. SSL Based VPNs are also called WebVPN in Cisco terminology. The two general VPN categories […]
Cisco Aggregation Services Router 9000-ASR 9000
The ASR 9000 has 6 times more capacity and is 4 times faster than any other router in the same category. It is able to transmit data at a rate of 6.4 terabits per second. What does this mean? It means that it is capable of transmitting 200 dvd video / sec or 250.000 mp3s […]
Connecting two Cisco Unified Communication Manager Express with H323
The Cisco Unified Communications Manager Express (CUCME) is the new brand name given by Cisco to the older Call Manager Express (CME) system. The concept is the same however: IP Telephony software running on Cisco routers. Therefore, the CUCME is a normal Cisco router (models supported are 1800, 2800, 2900, 3800, 3900 series) with a […]