[openssl-users] Troubleshooting SSL connections
paul.greene.va at gmail.com
Thu Nov 2 14:23:49 UTC 2017
I've got two servers that need to communicate with each other using SSL.
The applications that are supposed to talk to each other are custom in
When I try to connect to the upstream server, you can see the initial
connection established - "Connecting to "<upstream server><ip
address>":8443 ... connected"
Then you get "Initiating SSL handshake. SSL handshake failed. Closed fd
3. Unable to establish SSL connection"
The network path between the two servers is rather convoluted - the IP
address of my server gets NATed at least twice, it passes through a
couple of different firewalls, proxy servers, and load balancers. The
upstream server is on a public IP address, but the path to get there is
an internal network that doesn't hit the public internet directly.
As a test with the application administrator, I cloned my server and
moved the cloned copy (vmware servers) to a public IP address and
attempted the connection from there, and it worked without an issue. The
connection was established and it started polling the upstream server
the way it was supposed to. That should indicate that there isn't an
issue with either the server I'm managing or the upstream server, and
the problem must be somewhere in the network in between. (the upstream
server has been up and running for at least a year, so I'm pretty sure
there is no issue with their server itself)
There's three different tech support groups that I have to deal with to
troubleshoot this issue. They all have monitored the traffic and seen
the initial connection being established, so they believe there is
nothing on their side blocking the traffic, but no one can determine why
the SSL connection keeps failing. But something, somewhere in that
network path is messing with the network stream when it comes to
processing the SSL packets.
Sorry this post is rather convoluted and long winded - what I'm hoping
is that someone might suggest what might be happening here that is
messing with the connections (because this is an openssl list and the
problem is related to failing ssl connections). I don't manage or have
control over any of the network devices in between, so all I can do is
suggest something "out of the box" that they might not have thought of
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