LinuxCNC Mesa card and network

Hello, When linuxcnc run (with a mesa card) it is not possible to use the network.
As I see on forum I installed network-manager but this doesn't solve the problem.

When I run linuxcnc, I am unable to ping the local router...

How can I solve this issue ?

Many thanks for your help.
Best regards
 

Many thanks for your reply. The machine has only one ethernet interface. I am very surprised that it can not be possible to use the ethernet when linux cnc is running.
How can I load the gcode file in the Linuxcnc application? Is that some alternative? I see on a forum that installing network manager solve the issue, but not for me...

No wifi....
I don't understand why the ethernet connection is 'blocked' when linux cnc run. Is that a linuxcnc design? Is it a possible to load a file from the network?

If I modify the machine and will have two Ethernet Interfaces, can I connect both Ethernet interfaces in the same switch ? ie one for the mesa card and one for local network ?

The Mesa card requires a dedicated point to point ethernet connection so the real time performance is not affected by network latency.  Its not a generic network device to install on your network. To also connect to the internet you must use a seperate NIC or wifi connection.

The documentation for th  hm2_eth driver tell syou how to set a fixed IP addres for the NIC on the PC. Asssuming the ip Address of the mesa card is 10.10.10.10, use 10.10.10.1 at the PC end. 
linuxcnc.org/docs/devel/html/man/man9/hm2_eth.9.html

Ok it's very clear now !
So If I add an interface, I will be able to load a file from a file server using the second interface.
Best regards

Thierry Vorms