configuration questions on my cisco router

need some assistance with my cisco 1841.  i have an app on my phone that needs to get info from a pc inside our network.  very green on cisco ios but was able to config an entry that worked for a while, however im now learning i did not add the entry to the startup routine and low and behold the power went out and now the app is not connecting anymore.

here's what i into the router,

typed "config t" to get into config mode

typed "ip nat inside source static tcp <inside IP address> 80 <public IP address> 80 extendable"

(used my internal static assigned to that pc, used the port number i assigned in the software im communicating with which is not 80, and my public external ip)

type "end" to exit config

then exited my telnet session.  got on my phone and it worked perfectly for months.  till a power outage caused the router to reboot.

im now realizing once i exited the config mode i think should have typed "copy run start" to add that line to my startup?

so is that line somewhere still in the router but not in effect obviously as i cant connect with my phone anymore?  or can i do it exactly the same again but this time do the "copy run start", then exit my telnet?

how do i look to see if the command is still in there hidden somewhere?
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Dan CraciunIT ConsultantCommented:
show history

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It should show you the last 10 commands you typed.

To copy the running configuration to use on startup:
copy running-config startup-config

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coonastyAuthor Commented:
show history did not show anything.  

i guess im asking is the original ip nat command that i did not add to the startup, is it gone once the router rebooted?

do i simply need to just do the exact same thing i did to get it working then this time copy it to the startup config?
When you use "config t" to edit the configuration, you are editing the "running config", which is NOT stored in flash, so is lost during a reboot.

When you have finished editing the running config, you can use the command "copy run start" to copy the running config to the startup config. The startup config is read when (you guessed it) the router starts up.

If you want to see the two configs, you can do "show run" and "show start" and compare the two.

If you want to include just some lines about NAT, then you could do:

show run | i nat
show start | i nat

which will match any lines that have the string "nat" in them.
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To specifically answer you last two question:

is the original ip nat command that i did not add to the startup, is it gone once the router rebooted?


do i simply need to just do the exact same thing i did to get it working then this time copy it to the startup config?

coonastyAuthor Commented:
ok ill do it again exactly like last time but of course after i exit the config t...ill type "copy run start".

so this will simply add that line to the startup and not affect anything else?  

it will be the exact same startup config but just have my ip nat line added so my phone app can connect to my computer?

If that is the only change you made (in config mode) then that is the only change that will be saved. If you want to be definitely sure, reboot the router again (so that it reloads the startup config as it is saved) and make the changes directly after that.
coonastyAuthor Commented:
and to really show my ignorance in cisco ios....if i log in and and at the first prompt, what the command to reboot router?
The command is "reload". You can't do it until you get to "enable" mode though (when you have a hash# prompt).
coonastyAuthor Commented:
is enable and config mode the same?  from first login i type "config t" then type "reload"?
You should type "reload" from enable prompt. If you type this command in config mode it will give you an error (unrecognised command), eg:

% Invalid input detected at '^' marker.

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As opposed to doing it from enable mode where it will prompt you to confirm reload:

Proceed with reload? [confirm]

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Don JohnstonInstructorCommented:
Here's what you need to do (assuming that command was the only thing changed):

config t
ip nat inside source static tcp <inside IP address> 80 <public IP address> 80 extendable
copy run start

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You don't need to reload the router.

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