2 Replies Latest reply: Jun 22, 2009 7:22 AM by Nicolas MICHEL RSS

    Flash: config.text

    Nicolas MICHEL

      Hello guys !

       

      I passed my CCNA last january and actually studying for my BCMSN but I found something today and could't understand it . So I decided to ask here if some you guys could help.

       

      A switch and a router load their startup-config from their NVRAM right ?

      So on my switch when i do show flash: I can see a config.text file

      Then I do a more flash: config.text i can see my startup-config ... And when I delete, my startup-config , the config.text disappear ... So What's the deal ?

       

      Does my switch loads the startup from the NVRAM of from the FLASH ? Does the flash acts only like a backup of the nvram startup config file ?

       

      I don't get that point .....

       

      Anyway here is my real problem , Swtiches won't allow me to change the config-register via the global command . So how I can i ask the switch to get an IP from a DHCP server and how can I download my startup from a TFTP when it boots    (I know it's a silly method but I have to do it )

       

       

      Many thanks for the help guys

       

      BTW if someone is interested : I did a HSRP Summary here

       

      http://winol.free.fr/?p=134

        • 1. Re: Flash: config.text
          Paul Stewart  -  CCIE Security

          I think the switch actually stores the configuration in flash:config.text.  That is actually how you go through the password recovery process.  As for your task, I'm not sure you can do that without any configuration.  One way would probably be to have "boot config-file tftp://<ipaddress>/filename in the configuration file initially.

           

          The other option (and the one it sounds like you are looking for) is that I am pretty sure that most of the Cisco switches will do DHCP on VLAN 1 out of the box.  So if that is the case, you may be able to use the "bootfile" option along with option "150" in the dhcp server to signal to the switch which config file to use.  Even without the bootfile option, the switch may boot up and request common filenames like "network-config" and "cisconet.cfg". Just deliver the tftp server address to it via DHCP, delete the configuration, reboot and see if it tries to talk to the tftp server.

          • 2. Re: Flash: config.text
            Nicolas MICHEL

            Thanks Paul for the help

             

             

            I'll try this in my lab before implementing it on my production network

             

            I'll keep you informed if I have difficulties , that will help some readers too

             

             

            Nicolas