Category: Router Config

If we want to send previously prepared configs commands to Router via TFTP we can do this in very simple way and in this article we will se how to do it on Cisco and Juniper device.

CISCO

When we use TFTP to download configuration commands to the router, he is not making an echo of each command which reduces overall time consumption, CPU consumption and increases speed.

In this example, we will configure this router by making it receive the file named RConfig from the server at 20.20.1.1 by using the Trivial File Transfer Protocol – TFTP. The router will use the whole file received via TFTP before entering all the commands into the running configuration. This is particularly good because some commands in the configuration process could prevent your access to the router by locking you out or disconnecting you from the network, but the rest of the commands might fix the issue. If you enter the same configurations manually using telnet or “configure t”, you would simply lock yourself out of the router and not be able to continue with your work. A usual example of this issue happens when you change an active access-list. When you enter the first line, the router puts an implicit deny at the end, which will break your connection. Entering commands by using TFTP avoids any of this kind of problem.

In the first article we said some basic things about LLDP protocol and what is he doing. In this part, we will show all commands that can be inserted into Juniper router to make it run LLDP.

In this article we will see how you can easilly configure and tune router CDP capabilities. If you are more interested in what CDP really means and how it works, visit “about CDP” article.

• Cisco config

Address Resolution Protocol (ARP) cache is a table where router or computer is keeping Layer 2 MAC addresses to Layer 3 IP addresses mappings which hw resolved lately. Without MAC to IP mapping the device would not be able to build and send IP packets.

Device discovers the MAC to IP mapping using ARP protocol Broadcast requests on the local subnet and saves the mapping in the ARP cache. If a device wants to send a packet to a neighbour, and it doesn’t have a corresponding MAC address, it sends out a broadcast ARP request packet. This broadcast packet reaches every device on the local subnet. Everybody will receive that ARP request packet but only the one device with the IP address mentioned in  ARP broadcast request packet responds back with an ARP response packet to complete the process.

If You want to create aliases on Cisco device for commonly used or complex commands we will show you how in this short configuration article.

You can create command aliases on your router with the alias command: