Cisco "copy startup-config tftp" results in a 0 byte file on the server?

Question

I'm pulling my hair out figuring this out. My startup-config is good, I can view it with a show command. I'm trying to copy it to a tftp server:

asa5505# copy startup-config tftp

Address or name of remote host []? ipaddress

Destination filename [startup-config]? t
!!
%Error writing tftp://ipaddress/t (Timed out attempting to connect)

On my TFTP server (SolarWinds), I get the following:

binary, PUT. Started file name: C:\TFTP-Root\t
binary, PUT. File Exists, C:\TFTP-Root\t
binary, PUT. Deleting Existing File.
binary, PUT. Interrupted by client, cause: The process cannot access the file 'C:\TFTP-Root\t' because it is being used by another process

I've used tftpd32 with same results. I've tried different servers, even one on the same network as the asa ... same results. It'll create a 0 byte file and never do the dump. What's going on? Everything is working normally except for this.

What happens when you try to copy a file to/from from a non-Cisco TFTP client? — user48838, Oct 26 '10 at 21:42
Are the "test" clients and the Cisco unit in the same network? — user48838, Oct 27 '10 at 01:53
Then you might check the interface settings (maybe line, MTU, etc.) which is being utilized for the TFTP transfers on the Cisco. — user48838, Oct 27 '10 at 05:43

score 2 · Answer 1 · answered Jan 19 '21 at 22:51

The zero byte indicates that cisco sent the WRQ command to tftp port (69). The file is created at this step. The problem happens after this point.

The server acks from a different port to the cisco client tftp port. Cisco, then, sends the data to this different port.

The problem might be either with the ack not reaching or being rejected by cisco or the server rejecting the first data packet from cisco. The first problem is normally a firewall/acl issue while the second one could also be MTU mismatching. If you set jumbo frames on, cisco will use that for its outgoing traffic, including tftp.

score 1 · Answer 2 · answered Oct 13 '11 at 18:54

1

Looks like the answer is right in the question:

binary, PUT. Interrupted by client, cause: The process cannot access the file 'C:\TFTP-Root\t' because it is being used by another process

It's a problem with the TFTP server. Fix it there.

answered Oct 13 '11 at 18:54

MikeyB

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I think it's a problem with the path the cisco TFTP client is requesting to write to. Works from other TFTP clients . . . – Craig Constantine Nov 08 '11 at 18:32
If you delete the 't' file on the server first and then try the transfer again, what shows up in the log? – MikeyB Nov 08 '11 at 20:24

score 1 · Answer 3 · answered Sep 21 '12 at 13:06

1

not experienced with Windows TFTP servers, but with tftpd-hpa on Debian and the built in TFTP server on Mac OS X, I found I had to create the file first, make it world writable and then push the tftp file from IOS.

Then it worked.

answered Sep 21 '12 at 13:06

Squeeb

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score 0 · Answer 4 · answered Sep 12 '11 at 02:46

You may have to specify some or part of the TFTP-server-side path in your Cisco command. I haven't done this in a while. But I recall having a TFTP server that had rules that you could only write into a sub directory. So its TFTP dir was home'd in like /usr/tftp and writing was only permitted into /usr/tftp/incoming and, (this doesn't seem to be a problem in your case,) it only let you write onto existing files. So I had to 'touch' a file (eg, 'cisco.config' in my example here,) on the TFTP server first too. Then on the Cisco I had to say...

copy conf tftp
host.example.com
incoming/cisco.config

...so my "answer" is: check that your specifying any relative path that the TFTP server expects. Other TFTP clients might be doing that behind the scenes for you . . .

Interesting I'm getting down voted for suggesting the problem might with the path he's specifying on the Cisco's TFTP command. OP states the TFTP server works from other TFTP clients. People are upvoting the answer that misses this aspect of OP's description? Curiouser and curiouser. — Craig Constantine, Nov 08 '11 at 18:31

score 0 · Answer 5 · edited Oct 17 '12 at 08:40

0

Have you tried the deprecated write net to copy to TFTP?

edited Oct 17 '12 at 08:40

HopelessN00b

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answered Sep 20 '12 at 21:01

Fred

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score 0 · Answer 6 · answered Sep 21 '12 at 11:15

0

Did you delete

C:\TFTP-Root\t

before TFTP copy ?

It looks that file is already exist and it's locked by other process, so TFTP can not rewrite it.

answered Sep 21 '12 at 11:15

score 0 · Answer 7 · answered Jan 07 '19 at 12:48

0

set the interface, you are using for tftp as source interface. Here is the command,

#ip tftp source-interface gigabitEthernet 0/0

answered Jan 07 '19 at 12:48

Babasaheb

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Cisco "copy startup-config tftp" results in a 0 byte file on the server?

7 Answers7