Often when typing commands in a hurry, or just typing incorrect commands, Cisco routers will try to do a lookup to find out if the invalid command is the name of another device you are trying to connect to. This results in the router displaying ‘Translating “the command”…domain server (255.255.255.255)’ three times and not accepting […]
In yesterday’s post ‘Static Routing’ we saw that we needed to create a static route to allow the Cisco router “AOIP.ORG” to ping “R2”. The static route that we created was ‘ip route 10.0.1.0 255.255.255.0 192.168.1.1’ and ping was successful to the IP address 10.0.1.2 (R2’s Serial interface). The problem with that configuration was that […]
One of the first steps in troubleshooting a network, is to identify if the lines (links) are operational. On a Cisco router, the quickest way to see all lines as well as their status is by using the “show ip interface brief” command. In the live demo below, you will see that I have […]
In order to set up an IP address on an interface, we need to be in the interface level of the command line. This is a level within the global configuration level. From global configuration mode, we can enter the ‘interface serial 1/0’ command. If you are unsure of what interfaces are on the router, […]
Every Cisco device has 2 sets of configurations. On routers and switches these configurations are called ‘running-config’ and ‘startup-config’ When you make any changed on a router or switch, the change applies to the running-configuration and will affect the router or switch with immediate effect. However, if the device is reloaded for whatever reason, all […]
It is advisable that on all your devices in your network, you have a disclaimer or message that appears when someone connects to your device. There have been many cases over the years where a hacker has gained access, been caught, and got away with it since there was nothing in place informing that they […]
Using the Pipe ‘|’ is by far one of the most important things you can learn on a Cisco device. I never really appreciated this command when I started out in Cisco, as it seemed to take me longer to use it, and I didn’t get to see what I was looking for. In hind […]
One of the most annoying things I kept doing when I started out in Cisco, was constantly typing ‘show’ commands when in the wrong level of the configuration. By default, Cisco only allows you to do a ‘show’ command when you are in privileged mode (AOIP.ORG#). This can be frustrating when you are multiple levels […]
VTY (Virtual Terminal Lines) are used when you wish to telnet into a router remotely. In order for the router to allow telnet connections, the VTY lines need to be configured with a password, which is not a default setting. If you were to try connect to a router with telnet and the VTY password […]
The first thing to get used to on a Cisco device, is how to navigate. When you first connect to the Cisco device, you will see the following Would you like to enter the initial configuration dialog? [yes/no]: In most cases, using the configuration wizard is not the best idea, so at this point you […]