TFTP sends 0Kb files to Linux

[action711]

 We are in the process of upgrading our 3650s to 9300s

On our 9300s we have archive set up to tftp the config on every write to a Linux tftp server.

However, the files appear as 0kb.

I can tftp successfully to a windows server running tftp64 from the 9300s

I can tftp successfully from every other network box to the linux server, it's just the 9300s that write 0kb files.

The 9300s are all running 16.6.4

Any ideas please?

[marce1000]

 Re-check credentials for the designated linux tftp server. Also check the tftp server's logs  around the time the 9300 connects, check for errors (e.g.) ; check whether authentication is successful (e.g.)

M.

[action711]

When a 9300 writes to the tftp server I get this in the logs:

smbd: pam_unix(samba:session): session closed for user nobody

The same happens when a 3650 does a write, so no clues there. It's tftp, so there's no authentication at all, right?

If I tcpdump tftp (I know!!) then I get the following:

9300:

15:45:18.587868 IP (tos 0x0, ttl 253, id 0, offset 0, flags [none], proto UDP (17), length 72)

    xxxxxx-car4-stack00.xxxxx.com.53053 > xxxxx-sec01.xxxxx.com.tftp:  44 WRQ "-Dec-28-15-45-18.596-1" octet blksize 8192

3650:

15:45:57.705803 IP (tos 0x0, ttl 254, id 0, offset 0, flags [none], proto UDP (17), length 70)

    192.168.230.40.59997 > xxxxx-sec01.xxxxxx.com.tftp:  42 WRQ "xxxxxx-mcr01--Dec-28-15-45-57.692-7" octet

The only difference between the 2 is the 9300 includes a blksize figure, but again, no real clues there....

I'd be pulling my hair out, but I have none left :(

[marce1000]

 - Is there any error in the 9300's logs just after  the time of the intended tftp and or tftp failure (issue show logging just after the tftp is attempted) ?

M.

[action711 · Accepted solution]

Solved!!!

So it WAS the blocksize.

On the switch I issued

ip tftp blocksize 512

and now it writes fine!

Now all I need is a cure for baldness

[marce1000]

- Great!