Post Views: 1,725 In this How To, we explain Cisco SNAT. Cisco SNAT allows two or more routers performing the NAT function as a group. This is really handy for redundancy purposes, and can be used in conjunction with Cisco’s HSRP function (click here to see how HSRP is configured). The NAT routers are going […]
Stateful Network Address Translation (SNAT) Feature on Cisco IOS Routers Read More »
Post Views: 3,384 This one is short and sweet. Is your traceroute responding with “* * *”, or did you enter 1000000000 for the number of extended pings? Easy – simply type CTRL-SHIFT-6 to break the process. That is the Control Key (hold down), the Shift Key (also hold down) and the “6” key –
Stopping PING or TRACEROUTE on Cisco IOS Routers Read More »
Post Views: 2,250 Monitoring the traffic pattern on a network are essential in today’s network. If network administrators do stay on top of the traffic patterns, they may make crucial mistakes in network provisioning or design. With the Internet in a constant state of flux as new and hot applications emerge, this task becomes even
Netflow Basic Operations in Cisco IOS Read More »
Post Views: 2,179 How many times have I received a router that has no operating system on it? Way to many!! You turn on the router and it comes up in ROM Monitor mode (ROMMON). There is a way to get the operating system on the router from ROMMON. Below, I have documented the procedure.
Upgrading IOS on a Cisco Router in ROMMON Mode Read More »
Post Views: 2,187 The order of operations is hard coded into Cisco IOS and tells the router how to process traffic according to the configuration of different router functions and features. While we cant’ make you think like a router, it is likely you have already picked up on some of these. When configuring features
Order of Operations in Cisco IOS Read More »
Post Views: 1,419 What is NBAR? NBAR is a powerful packet filtering/identification/firewall that you may already have installed on your Cisco router. For a list of what NBAR can detect look here. NBAR is also what we call Cisco’s “autopilot” for QoS. It has been in IOS since ver. 12.0 and has been continually updated
NBAR Explained in Cisco IOS Read More »
Post Views: 1,835 As we said in our basic ACL How To, ACL’s’ are vital to networking today. Everyone uses them, and proper usage is imperative. In this How To, we are going a little deeper into two ACL types: Intrastructure and Transit. We will discuss the two with examples and you will clearly understand
Access Control to Infrastructure (iACL) and Transit (tACL) Read More »
Post Views: 2,301 ACL’s’ are vital to networking today. Everyone uses them, and proper usage is imperative. Besides being difficult to use at times, the penalty for an ACL mistake is huge. In one swift swoop, you could incorrectly permit malicious attackers onto your network or incorrectly deny all valid users from your network. Either
Access Control List (ACL) Basics Read More »
Post Views: 1,493 What is AAA? It stands for Authentication, Authorization, and Accounting. When it comes to network security, AAA is one of many features a network manager may use. Here is what each of these are used for and why you should care: Why every network admin should care about AAA Besides passing certification
AAA Usage in IOS Classic Read More »
Post Views: 1,623 This How To explains how to fix an annoying default behavior on Cisco IOS. Mistype a command on a Cisco router and the router thinks you just typed a hostname. This is often an annoying problem. For example: Router#shwoTranslating “shwo”…domain server (10.1.1.1) % Unknown command or computer name, or unable to find
Stopping the Cisco Router from Trying to TELNET Read More »
Post Views: 1,503 This How To explains the fundamentals of configuring EIGRP. EIGRP is an advanced distance-vector routing protocol that is used on a computer network to help automate routing decisions and configuration. The protocol was designed by Cisco Systems as a proprietary protocol, available only on Cisco routers, but Cisco converted it to an
EIGRP Configuration in Cisco IOS Read More »
Post Views: 2,052 What happens if there is a system or user on a VLAN that is infected by malware or is deliberately running a scanning program? This can cause a massive amount of entries in the CAM Table of the switch. Think of the CAM table as the MAC address table. There is a
CAM Table Overflow Attack Mitigation on Cisco Switches Read More »
Post Views: 2,442 When a router has to forward a packet, it looks in its routing table to match as many bits as possible of the destination address to a route in its routing table. This is known as longest match routing. Once a match is found, the router forward the packet to the next
Administrative Distances in Cisco IOS Read More »
Post Views: 1,622 It is a great day! Mr. Walding’s book on MPLS is now available on the iTunes/iBooks! This book on MPLS (MultiProtocol Label Switching) reveals what MPLS is, how it works, what services it provides, and what problem it solves in networking. Instead of reading dozens of standards documents, this book summarizes
Mr. Walding’s Book on MPLS Released Read More »
Post Views: 2,696 Check out these great references as well: Our custom profiles repository for Wireshark Our Udemy course on Wireshark Our Udemy course on Wireless Packet capture As more and more of you are moving to Voice over IP, you will want to use Wireshark to do voice analysis. But first, you may want
Using tshark for Packet Voice Read More »
