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How to Copy IOS Image on Router from Internet

Hi Guys,

I am sitting on Internet and want to copy IOS Image to router. I can SCP, itu authenticated to Router but ends with a message "host is not communicating for more than 15 seconds".

Router :               Cisco 2821

Current IOS:       (C2800NM-ADVENTERPRISEK9-M), Version 12.4(24)T1.

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New Member

How to Copy IOS Image on Router from Internet

Hi Edison,

This could Solve my problem if my machine had Public IP assigned but my machine is Inside a Corp Network behind the Firewall which gives me Firewall IP as my Public IP Address(Due to NAT). Only thing which could work for me was FTP which I tried and it was successful but Copying on FTP and again from FTP to Router, It will take almost 8-10 Hours. not sure about RCP.

but thanks I Got the answer here which is helpful and I have option for FTP here.


Super Bronze

Re: How to Copy IOS Image on Router from Internet


The  Author of this posting offers the information contained within this  posting without consideration and with the reader's understanding that  there's no implied or expressed suitability or fitness for any purpose.  Information provided is for informational purposes only and should not  be construed as rendering professional advice of any kind. Usage of this  posting's information is solely at reader's own risk.

Liability Disclaimer

In  no event shall Author be liable for any damages whatsoever (including,  without limitation, damages for loss of use, data or profit) arising out  of the use or inability to use the posting's information even if Author  has been advised of the possibility of such damage.


8-10 hours?  What's the public side bandwidth?

Two things that might help could be setting the router's RWIN to 64 KB and enabling PMTUD.  Enabling SACK might help too.


ip tcp selective-ack

ip tcp window-size 64240

ip tcp path-mtu-discovery

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