Occasionally I have an issue when I try to SCP a file to one of our Cisco devices. When the connection starts, it immediately drops and says "lost connection". I've had this happen when there wasn't enough space on the flash drive but this isn't the case today.

Below is the failure from a 3750X switch and the pertinent config info from the switch.

laptop:C3750X user$ scp c3750e-universalk9-tar.150-2.SE4.tar cisco@
c3750e-universalk9-tar.150-2.SE4.tar            0%    0     0.0KB/s   --:-- ETAConnection to closed by remote host.
lost connection
laptop:C3750X user$ ssh cisco@

temp#sh run | sec aaa
aaa new-model
aaa authentication login default local
aaa authorization exec default local 
aaa session-id common
temp#sh run | sec ssh|scp
ip ssh version 2
ip scp server enable
 transport input ssh
temp#sh run | sec line
line con 0
line vty 5 15
 transport input ssh
Directory of flash:/

  526  -rwx         616  Mar 30 2011 01:39:31 +00:00  vlan.dat
  527  -rwx        2072  Mar 30 2011 01:40:52 +00:00  multiple-fs
  528  drwx         512  Mar 30 2011 03:23:11 +00:00  update
  529  -rwx        2955  Mar 30 2011 01:40:52 +00:00  config.text
  530  -rwx        3561  Mar 30 2011 01:40:52 +00:00  private-config.text
    2  drwx         512   Mar 1 1993 00:12:47 +00:00  c3750e-universalk9npe-mz.150-2.SE3

57671680 bytes total (31971328 bytes free)

I forgot to include the user section but cisco/cisco is a temp account with privilege 15.

Any ideas why SCP is failing when SSH works just fine?

EDIT: SCP debug output

Mar 30 03:33:37.452: SCP: [22 ->] send <OK>
Mar 30 03:33:37.687: SCP: [22 <-] recv C0644 25548800 c3750e-universalk9-tar.150-2.SE4.tar
Mar 30 03:33:37.704: SCP: [22 ->] send <OK>
Mar 30 03:33:38.400: SCP: [22 ->] send Write failed
  • 2
    Here you are pushing a file from your laptop to the switch. What happens when pull the file, by running the copy command on the switch?
    – jwbensley
    Jul 29, 2013 at 12:30
  • That should be the solution. I haven't been successful with pushing files to Cisco devices, in general.
    – netdad
    Jul 29, 2013 at 21:26
  • 1
    Pulling files to it works but I don't see that as a solution. I run scripts off my laptop, so pushing is needed. Pulling is a workaround. Aug 1, 2013 at 14:51
  • 1
    @legioxi Try adding -v on the SCP command to get a more verbose output of what's happening.
    – Ryan Foley
    Dec 24, 2013 at 15:06
  • 1
    Can you update the post with the output of the solutions proposed?
    – Ryan Foley
    Jul 22, 2014 at 15:15

4 Answers 4


So, just to make sure that you haven't simply missed or misconfigured a step. Check Cisco's guide to SCP here

Also I noticed that your scp command was in the form

 scp image.tar cisco@

You may want to try

scp image.tar cisco@

I added flash: per the sugggetion in this support forum on cisco.

So, just to break it down, make sure you have an AAA model created, a user created, and the scp server enabled, then try it again. Also try connecting with the flash:.


For others that come across this, here is my solution. I had the same issue, similar scenario:

$ scp c2900-universalk9-mz.SPA.155-3.M.bin user@ Password: c2900-universalk9-mz.SPA.155-3.M.bin 0% 0 0.0KB/s --:-- ETA lost connection

This was my fix:

$ scp c2900-universalk9-mz.SPA.155-3.M.bin user@

  • It seems dumb, but this solved it for me. I don't know why you should need to specify the destination file name.
    – Tim G
    Sep 13, 2017 at 0:46

I'll just attempt to enter an answer.. I've never seen an scp copy to a Cisco device work in the way you are trying to do it.

I believe you should be able to use the Cisco Flash MIB to do remote pulls (initiated by your management server, as you are trying to do.)

I believe this article should help you accomplish this.



It works except on ASA devices. The key is you have to have destination file name. Whether you use x.x.x.x:flash:filename or x.x.x.x://filename

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