Hello Athmane,
At first glance, this does appear to be a network connectivity issue with your VM/Host. Here are a few things to check in the config to ensure the system is configured as you expect. These commands are to be run in the LROS Shell.
DNS Name Server:
Ensure there is an external DNS Resolver configured in "show ip dos". If there are no servers listed here under "Name Servers:" you can configure them with "ip dns" followed up "name-server a.b.c.d" in configure mode.
See this page for more detail: https://docs.lineratesystems.com/087Release_2.6.1/200CLI_Reference_Guide/Configure_Commands/IP_Mode_Commandsname-server
DNS Resolution:
When you have confirmed a name server is configured properly, try running a query on it. The following command will test whether you are able to successfully resolve the address of the F5 licensing server. If this doesn't work, you may want to change the name-server you are using for your DNS resolution.
bash "nslookup license.f5.com"
IP Config:
Check "show ip interfaces brief" and ensure em0 has an IP address for the LAN that interface is on. If not, take a look at the docs to configure one:
https://docs.lineratesystems.com/087Release_2.6.1/200CLI_Reference_Guide/Configure_Commands/Interface_Mode_Commandsip_address
Intermittent connectivity?
From your host machine (or another one on the LAN of your em0 interface), try and run a sustained ping to the IP Address of em0. If you see drops periodically, something on your network may not be behaving properly. I would troubleshoot there.
These troubleshooting steps should get you started. Also, you mentioned this is using VMWare Player, so you may get some issues resolved by restarting your Host machine. Let us know how this goes!
-Andrew