10 second delay when using vnc over ssh session

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phil.e
Posts: 97
Joined: 2018/02/13 20:28:14

10 second delay when using vnc over ssh session

Post by phil.e » 2021/02/02 23:02:53

I've got a user using ssh to get to another server, and then from that server using vnc sessions to do their work. Every time he does an action, there is about a 10 second delay before the action takes place, which makes for a very painful way of working.

We've had an issue with GSSAPI authentication where when that is enabled, it causes delays because we don't use that in our network. That is disabled in both ssh_config and sshd_config.

It appears to be a user profile related issue because he gets the same issue when using the workstations of others that do not experience the same problem. I looked through ~/.ssh and ~/.vnc to see if there might be some options in there that might be causing problem, but .ssh only has known_hosts in it and .vnc has a log file and a PID file.

His client is CentOS 6.10 (yes, I know, out of date - we're hoping to get off 6 completely by the end of March), openssh version 7.4, Tigervnc 1.1. The remote end is on CentOS 7.

Any ideas?

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TrevorH
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Joined: 2009/09/24 10:40:56
Location: Brighton, UK

Re: 10 second delay when using vnc over ssh session

Post by TrevorH » 2021/02/03 00:58:30

So you have this now?

Client -> Jump-host (user runs vnc here) -> target

I'd not do it that way at all. I'd use something like

[trevor@client]$ ssh -L:5901:targethost:5901 jump-host

Then use vncviewer 127.0.0.1:5901 on your client

So there you are going from client to jumphost and using that connection to open a tunnel going from your localhost:5901 to targethost:5901 then you're connecting vncviewer to your own localhost.

And if that works you can use ~/.ssh/config to automate it.
The future appears to be RHEL or Debian. I think I'm going Debian.
Info for USB installs on http://wiki.centos.org/HowTos/InstallFromUSBkey
CentOS 5 and 6 are deadest, do not use them.
Use the FAQ Luke

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