In this article we will define and discuss Default and Static Routes. We often see the incorrect implementation and understanding of ‘default routes’. The default route is a “gateway of last resort.” This special route tells computers or other routers to contact the defined next hop of the default router if they don’t have a […]
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Everyone knows that constantly entering commands on Cisco routers and switches can become uncomfortably repetitive. To make life somewhat easier, Cisco offers the alias command, which can help dispel part of this repetition. This is a Global Configuration command. To use it, enter the alias command and identify which privilege level you want to specify
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In this How To, we will discuss the clock setting in IOS. When Cisco IOS boots up, the default date and time is set to March 1, 1993. You can view this using the ‘show clock’ command: cell_pe1> show clock *00:01:10.415 UTC Mon Mar 1 1993 It isn’t necessary for a router to have
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‘Lines’ are physical async serial ports on the router (such as a terminal or modem), a virtual network connection, or another type of serial line on the router. To see which lines you have on your router, use the show line command: Cell_Router#show lineTty Typ Tx/Rx A Modem Roty AccO AccI Uses Noise Overruns Int0
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In this How To we will reveal how to bypass the system password on Cisco IOS routers. This procedure is used regularly by CellStream consultants. As you will see, we are changing the configuration register to alter the boot process to exclude the configuration files that the router has, as within those configuration files is
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In this How To we will reveal how to bypass the system password on Cisco IOS routers. This procedure is used regularly by CellStream consultants. As you will see, we are changing the configuration register to alter the boot process to exclude the configuration files that the router has, as within those configuration files is
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Let’s say you’re implementing some changes on a router that has a large configuration file. Maybe something distracted you when you were making the change, but the new feature doesn’t work when you go to test it. You just want to back everything out and start from scratch. How can you do that? You have
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GLBP is a new protocol similar in function to HSRP (discussed here). It has been available since IOS version 12.2(14)S and you can read more at the Cisco site in this article on Gateway Load Balancing Protocol. GLBP and HSRP are both Cisco proprietary solutions, but VRRP is an open standard based on RFC 3768.
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This How To explaing how to use Extended Ping and Extended Traceroute options in Cisco IOS. Extended Ping The ping command is just about as simple as it gets when it comes to troubleshooting. Ping is actually ICMP. ICMP sends a encho request to a particular address and, if present, that device send back an
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In this How To we will discuss the process for backing up and restoring configurations of your Cisco IOS devices. Whenever you have a good working configuration, it is always a good idea to create a backup – I like to call them “golden configurations”. This way, if you make changes that cause problems, you
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This How To will explain the process to back up your IOS image. Your IOS image is stored as a file in the non-volatile memory of your switch or router. This image file is compressed to reduce its size and reduce the transfer times as much as possible. Before starting the procedure of IOS file
This How To addresses the method of limiting bandwidth on ports of a Cisco Switch or Router. Why should you limit bandwidth? There are a number of reasons for limiting bandwidth on a Cisco switch Ethernet port. For example, let’s say you work for an Internet service provider in a colocation facility, and you sell
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While RIP is not used for the ‘real’ Internet routing, and hasn’t been for many years, we often use RIP to do testing as it is so quick and easy to configure the protocol. Also, if you are learning shortest path routing for the first time, RIP is a great place to start as it
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In our high level overview of QoS we stated that configuring QoS can be complicated. Cisco developed NBAR as the QoS ‘autopilot’ as one solution to this problem. More recently, Cisco has developed something called AutoQoS, which also configures QoS settings for you. You can use AutoQoS to a)create policies based on real-time traffic flowing
This How To covers something called Black Hole Routing using the NULL interface in Cisco IOS. The entire YouTube network went down in 2009, across the globe, for about two hours — thanks to a mistake made by an ISP in Pakistan. That mistake involved a black hole route accidentally distributed around the world. While
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