Post Views: 1,182 Many people are using VPN technology today to ensure data confidentiality between remote locations. When using a site-to-site type VPN (say between a Router and a Firewall), a common complaint among end users is intermittent delay before VPN traffic is successful. This is usually due to Security Associations (SA) becoming too old […]
Keeping VPN SA’s Refreshed in Cisco IOS Read More »
Post Views: 1,515 As many of our students and clients have learned, Spanning Tree in Layer 2 Ethernets is a basic control protocol that removes logical loops from physically looped networks creating the Spanning Tree. This How To focuses on the essential configuration commands in Cisco IOS that you need to know to manage Spanning
Spanning Tree Protocol Configuration Basics in Cisco IOS Read More »
Post Views: 1,779 IP mobility is software and hardware designed to provide network access as a user travels from network to network. Cisco calls this the ubiquitous connection. Cellular telephone networks already accomplish this: You can begin a cellular call in Los Angeles, CA and (in theory) you should be able to drive to New
IP Mobility Primer in Cisco IOS Read More »
Post Views: 2,658 When learning Cisco IOS, students often ask, what happens if there is conflicting information? Cisco IOS order of operations plays an important role in how a router processes traffic and makes choices, especially if there are two possible answers. If you’re simply using the most basic features of the router, chances are
Cisco IOS Order of Operations for NAT and QoS Read More »
Post Views: 1,725 The following is a quick example on how to configure Cisco’s HSRP protocol. Many net admins ask about redundancy in Cisco routers and the answer is usually always the same: If your uptime has to be high, and the thought of having a failure and suffering the downtime that it will take
HSRP – A Quick Configuration in Cisco IOS Read More »
Post Views: 1,460 Finding the right piece of information that you need from a Cisco router can often be a challenge. For example, if you use the show running-config command on a large production router, you can end up with 25 pages of text output. Locating that one piece of information you’re looking for can
Finding Configuration Details Quickly in Cisco IOS Read More »
Post Views: 17,942 Similar to a Windows or Linux operating systems that have a command line or terminal commands to manipulate files, the Cisco IOS (though rooted in Unix) and has its own list of commands to manipulate files. These commands are very similar to DOS/Windows commands. Files could be your IOS router operating system
File Commands and their Usage in Cisco IOS Read More »
Post Views: 1,432 What is EtherChannel? EtherChannel technology is another way for you to increase the bandwidth of your core network links and provide redundancy of LAN links. It allows you to achieve greater speed by bundling Fast Ethernet or Gigabit Ethernet links, which makes a switch or router use the merged ports as a
Configuring EtherChannel on Cisco Switches Read More »
Post Views: 3,137 No one wants it to happen but, sooner or later, you will experience a router crash. When you do, you will want to be prepared to save that critical router memory information in order to find out why the router crashed and prevent future crashes. To do this, you need to configure
Core Dump in Cisco IOS Read More »
Post Views: 3,342 In this article, I will explain steps to correct a CONFIG_RESOLVE_FAILURE error in Cisco IOS. \If you are like many users of the latest IOS, you may find your routers constantly outputting a message like this: cell_pe1# %Error opening tftp://255.255.255.255/cisconet.cfg (Timed out) 19:20:43: %SYS-4-CONFIG_RESOLVE_FAILURE: System config parse from (tftp://255.255.255.255/cisconet.cfg) failed The reason
CONFIG_RESOLVE_FAILURE error Quick Fix in Cisco IOS Read More »
Post Views: 3,037 Anyone who has network admin access can make changes to the running configuration on a router or switch at any time. If you are running a large IT shop or in charge of just a few folks, this feature will enable you to control the concurrent changes to your running configuration. Exclusive
Configuration Lock in Cisco IOS Read More »
Post Views: 1,147 Sometimes, we need to transfer IOS from one router/platform to another. Other times, we can end up in Rommon> prompt because an IOS download failed of similar issue. Let’s start with a stranded router. It is strongly suggested that you get a PCMCIA memory card, insert it into a good router. From
Copying Cisco IOS from One Router to Another Read More »
Post Views: 2,880 This How To discusses how to set up one Cisco Router as a PKI Server and one Cisco Router as a client. That’s right, you can set up a Cisco router as a Certificate Authority (CA) and then set up other routers as clients to use that CA to authenticate on your
PKI Server and Client Setup in Cisco IOS Read More »
Post Views: 1,822 CAR — or “rate limiting” — is a method for managing unwanted traffic on your network and making sure it doesn’t affect important traffic. Essentially, CAR controls the bandwidth of a certain type of traffic, and an access control list (ACL) defines which traffic it controls. Once you’ve created the ACL, you
Committed Access Rate in QoS with Cisco IOS Read More »
Post Views: 1,756 As VoIP becomes more widely used in the enterprise, the number of voice calls traversing the enterprise WAN becomes larger and larger. Typically the use of a proper codec is implemented to reduce the amount of bandwidth a voice call requires. The most commonly used codec for WAN voice traffic is called
Compressed Real Time Protocol (cRTP) to Streamline Voice in Cisco IOS Read More »
