SFTP Transfer aborted to 3650

[aweise]

I'm trying to transfer an IOS image down to a 3650 switch and on every attempt, I get the following:

%Error opening sftp://*@192.168.174.174/c1100-universalk9.16.12.05.SPA.bin (Transfer aborted)

This happens no matter what server IP I use (we have three). I've tested this with other 3650s at remote branch office locations and they all work.

Our firewall logs do show a difference - for the switch in question, we see the firewall log indicate the session was ended by a TCP RST from the client. For the switches where the SFTP works, the end of the session is a TCP FIN. Obviously, the switch I'm working with is the issue.

My question - has anyone seen this? What else besides a sniffer capture can I do to troubleshoot this?

[Leo Laohoo]

NOTE:  You're transferring an firmware meant for a 1100 router into a 3650, is that correct? 

How about TFTP?  

What is the current firmware version of the switch? 

Reboot the switch and see if it makes any difference.

[aweise]

Yes, I understand that I was transferring an 1100 image. I was just using that for testing purposes.

I thought about rebooting, but need to find a maintenance window to do so.

[marce1000]

 - In 'worst case' it could recognize that the image is wrong and abort , not sure that happens , to exclude use valid image for the device.

 M.

[Georg Pauwen · Accepted solution]

Hello,

is there a difference in the SSH settings between the non-working and the working switches ? Or the ssh source interface being used ?

https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst3650/software/release/16-11/configuration_guide/sec/b_1611_sec_3650_cg/sftp.html

[aweise]

Georg - good call. I had added the command "ip ssh window-size 131072" in an attempt to speed up the transfer. When I removed that, the SFTP transfer worked.

As for the other idea - all other switches were successfully able to download the 1100 router image, so I knew that wasn't the issue.

Thanks for the responses!