# mpiexec of pvserver on hosts that are firewalled off to each other ?
**URL:** https://discourse.paraview.org/t/mpiexec-of-pvserver-on-hosts-that-are-firewalled-off-to-each-other/7910
**Category:** ParaView Support
**Created:** [September 2, 2021, 12:15am UTC](https://discourse.paraview.org/t/mpiexec-of-pvserver-on-hosts-that-are-firewalled-off-to-each-other/7910 "2021-09-02T00:15:52Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@Nicholas\_Yue](https://discourse.paraview.org/u/Nicholas_Yue)
#### Post date: [September 2, 2021, 12:15am UTC](https://discourse.paraview.org/t/mpiexec-of-pvserver-on-hosts-that-are-firewalled-off-to-each-other/7910/1 "2021-09-02T00:15:52Z")
I have a number of GPU hosts (hostA, hostB and hostC) which are only accessible via ssh
The following works
```auto
hostA$ ssh hostB ls
hostA$ ssh hostC ls
hostA$ mpiexec -hosts hostA /nfs/path/pvserver
```
The following does not as only port 22 is opened
```auto
hostA$ mpiexec -hosts hostA,hostB,hostC /nfs/path/pvserver
```
Is there some way to setup an ssh tunnel for mpiexec to communicate ?
Cheers
---
### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [September 2, 2021, 8:28am UTC](https://discourse.paraview.org/t/mpiexec-of-pvserver-on-hosts-that-are-firewalled-off-to-each-other/7910/2 "2021-09-02T08:28:41Z")
> [@Nicholas\_Yue](#):
>
> Is there some way to setup an ssh tunnel for mpiexec to communicate ?
Yes.
Manually:
[https://www.paraview.org/Wiki/ParaView:Server\_Configuration](https://www.paraview.org/Wiki/ParaView:Server_Configuration)
Natively in ParaView:
> [@Using SSH Support to secure your client/server communication with ParaView](https://discourse.paraview.org/t/using-ssh-support-to-secure-your-client-server-communication-with-paraview/682):
>
> Since [mr](https://gitlab.kitware.com/paraview/paraview/merge_requests/2652) and [mr](https://gitlab.kitware.com/paraview/paraview/merge_requests/2821), ParaView master now has a support for ssh, which includes port forwarding. In order to use it, you will need first to install a terminal and an ssh tool. Terminals are available by default on Windows, Mac and virtually on all linux distribution. Ssh is available by default on mac, on all package manager on all linux distribution. On windows ssh is now available by default with the Windows 10 Spring update but we recommend installing [Putty](https://www.chiark.greenend.org.uk/~sgtatham/putty/) as support for rc connection is bett…
---
### Author:  [@Nicholas\_Yue](https://discourse.paraview.org/u/Nicholas_Yue)
#### Post date: [September 2, 2021, 9:05pm UTC](https://discourse.paraview.org/t/mpiexec-of-pvserver-on-hosts-that-are-firewalled-off-to-each-other/7910/3 "2021-09-02T21:05:22Z")
@mwestphal Thank you.
Currently, I am able to connect remotely from my Windows box to a pvserver running on a linux box call LinuxHostA and visualize the data.
[I am currently running pvserver on LinuxHostA only]
```auto
ssh -R 8000:localhost:8000 LinuxHostA /home/nyue/systems/Paraview/ParaView-5.9.0-egl-MPI-Linux-Python3.8-64bit/bin/pvserver --reverse-connection --server-port=8000 --client-host=WindowsUserWorkstation
```
I believe I am making some progress, the Paraview UI indicates parallel/remote rendering
What I am still unable to figure out is how to run the mpiexec on LinuxHostA so that multiple pvserver is launch on e.g. LinuxHostB, LinuxHostC
Using this [wiki](https://www.paraview.org/Wiki/ParaView:Server_Configuration) as a reference, which case should I focus on reading more carefully to formulate the setup run the `mpiexec pvserver` on the multiple hosts LinuxHostA,LinuxHostB,LinuxHostC with the constraint that the only port number opened is 22 on all the Linux hosts?
Cheers
---
### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [September 3, 2021, 7:33am UTC](https://discourse.paraview.org/t/mpiexec-of-pvserver-on-hosts-that-are-firewalled-off-to-each-other/7910/4 "2021-09-03T07:33:49Z")
This would be case height:
[https://www.paraview.org/Wiki/ParaView:Server\_Configuration#Case\_Eight:\_Starting\_server\_using\_ssh](https://www.paraview.org/Wiki/ParaView:Server_Configuration#Case_Eight:_Starting_server_using_ssh)
But you can just do it manually.