MikroTik

I am using VanDyke's SecureFX for accessing my boxes via SFTP.
However SecureFX fails to connect to a Mikrotik RouterOS device. At some point the connection process just stops.

People at VanDyke say there is a bug with Mikrotik's SSH server: it is sending a packet with an invalid "request-id" value.

Could you (the Mikrotik guys) please look into this? It should not be very hard to fix.

SecureCRT/SecureFX are very popular among system and network engineers.

I have attached a log file reflecting this issue.

Hi ners,
Mikrotik guys checks the forum quite often but your request can get lost due to high number of posts.
I strongly suggest you to send an email to support@mikrotik.com with your issue so it can get the correct attention.

I would begin by looking at your path MTU. Every ssh / ssl issue I have dealt with has been caused by a path MTU being less than 1500. Check your interfaces, VPN's, bridges, everything. I use SecureFX on Windows boxes and Forklift on my Macs with no sftp issues at all.

I contacted VanDyke's support and after an investigation they told me
the following:

> the SSH server is sending a packet with an invalid SFTP request ID.

> Here is the malformed packet SecureFX receives from the server: 00
> 00 00 2c 0d 5e 00 00 00 00 00 00 00 15 00 00 00 11 65 73 2d 6d 75 00
> 00 00 08 00 00 00 00 00 00 00 00
>
> The data suggests that the server is attempting to send an
> UNSUPPORTED message (00 00 00 08) in response to SecureFX's
> STAT/REALPATH request. But, the server supplies an invalid request
> ID (73 2d 6d 75), in violation of the SFTP protocol. Rather than
> assume or guess the server's intention, SecureFX terminates the
> connection.

So this doesn't look like an MTU problem (also WinSCP connects fine)