Failed connections 7.6 to 5.2

[Darren Tucker]

On 6 March 2018 at 12:39, CLOSE Dave <Dave.Close at us.thalesgroup.com> wrote:
> Trying to connect to a Dell iDRAC 6. The iDRAC reports it is running
> OpenSSH 5.2.
>
> From Fedora Linux 20 with OpenSSH 6.4p1, connections succeed.
> From Fedora Linux 23 with OpenSSH 7.2p2, connections succeed.
> From Fedora Linux 27 with OpenSSH 7.6p1, connections fail prior to

Compare the output of working and non-working configurations and pay
particular attention to the key exchange algorithms and ciphers
selected.

> debug1: SSH2_MSG_KEX_DH_GEX_INIT sent
> ... (long pause)
> debug3: receive packet: type 1
> Received disconnect from (IP address) port 22:11: Logged out.

I suspect your DRAC's CPU is to weedy to complete 8kbit Diffie-Hellman
within a reasonable time and you're hitting some kind of timeout.  You
could try one of the smaller key exchange methods (eg ssh -vvv -o
kexalgorithms=diffie-hellman-group14-sha1 yourdrac).

> There must be a setting to accommodate this situation. I have no way to
> upgrade the iDRAC nor to run with -ddd on it.

As the vendor what's going on?

-- 
Darren Tucker (dtucker at dtucker.net)
GPG key 11EAA6FA / A86E 3E07 5B19 5880 E860  37F4 9357 ECEF 11EA A6FA (new)
    Good judgement comes with experience. Unfortunately, the experience
usually comes from bad judgement.