Tag: tftp

TFTP via VRF

As you can see from my article list, I’m going through some VRF configuration in the last few weeks 🙂

I ran into this today and it sounded interesting enough to share it with you. The issue with TFTP IOS image copy to flash when having all interfaces in specific VRF and no interface in Global Routing Table.

Long story short, you kick in this command for normal IOS download to the router:

R1#copy tftp://10.10.10.11/c890-universalk9-mz.154-3.M5.bin flash:
Destination filename [c890-universalk9-mz.154-3.M5.bin]? 
Accessing tftp://10.10.10.11/c890-universalk9-mz.154-3.M5.bin...
%Error opening tftp://10.10.10.11/c890-universalk9-mz.154-3.M5.bin (Timed out)

…and it isn’t working of course.

Saving Router Configuration to Server

VoIP protocols functionalityIf you want to store a backup copy of your router’s configuration on a TFTP server we have a simple solution for you. This article will explain all the commands needed to save backup configuration of a device to TFTP server. All this for Cisco and also for Juniper device.

CISCO

You need to make regular backups of your router configuration files and keep copies in a safe place. If you have a serious failure that damages a router’s hardware or software, the configuration will be destroyed. And anybody who has had to reconstruct a complex router configuration file from memory will tell you how difficult and stressful this task is. But if you have a backup of the last working configuration file, you can usually get a router working again within minutes of fixing any hardware problems.

Use TFTP to configure a Router

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.