Cisco CUCM interop problem

Bruno_S · Post by **Bruno_S** » Tue Sep 12, 2017 2:12 pm

Hi there

I have an interop problem with the latest version and Cisco CUCM.
V. 2.1.1 was still working w/o issues, but with 2.1.4 CUCM is no more connecting and sending CDR's
I have a Wireshark, but no way to upload here...

Thanks
Bruno

cp · Post by cp » Wed Sep 13, 2017 4:33 pm

send info to feedback at coreftp . com

wireshark information may not be very helpful since most info is encrypted. if you have plain text logs available, include those.

cp · Post by cp » Thu Sep 21, 2017 7:53 pm

there were no SFTP packets in the wireshark trace. Good chance there was no connection to the server at all. You may need to plug in your hostname or IP into Options -> IP/Address.

Older versions may have been listening on the callback address for localhost (127.0.0.1) and newer versions might not. You can specify multiple addresses separated by a comma.

Bruno_S · Post by **Bruno_S** » Fri Sep 22, 2017 11:53 am

Just resent the trace for V 2.1.4.
There is communication on port 22 but it seems there are problems during key exchange. This was/is working fine with V. 2.1.1

Best
Bruno

cp · Post by cp » Fri Sep 22, 2017 5:56 pm

The 2.12 version did have a DH group exchange (gex) fix. It wasn't showing up in the DH exchange (even though it was supported and would work).

diffie-hellman-group1-sha1,diffie-hellman-group14-sha1,diffie-hellman-group-exchange-sha256

in the dh exchange was updated to show:

diffie-hellman-group1-sha1,diffie-hellman-group14-sha1,diffie-hellman-group-exchange-sha1,diffie-hellman-group-exchange-sha256

It could be that the Cisco CUCM has something cached (host key, etc) and then tries to use DH group exchange (instead of dh-group1) and it causes it to reject the connection. Knowing what the CUCM error is will be the most helpful information in terms of figuring out what the problem is.