No internet on my server

[Josep MO]

Hi, my server version is:
pve-manager/5.4-15/d0ec33c6 (running kernel: 4.15.18-30-pve

and I have a problem with Internet, I cannot do ping.I try all thing, but It doesn't run.
The problem was when I try to copy files between two VM, and the network was stop. It has happened to me again and after a few hours it has gotten well again, but I can not find the problem.
Everything worked correctly before doing the copying process between virtual machines.
It smells like a network or configuration issue to me, but I don't know where to look.

Ping to IP Proxmox is run, ping to IP Google is

Some help?

 

[Josep MO]

I have the problem, but I cannot find the solution.

 

[Josep MO]

please any help @dcsapak

 

[dcsapak]

1. please do not bump your posts without more information
2. do not use systemd-networkd on you pve, this will conflict with ifupdown/ifupdown2
3. please use a supported and current version of pve (6/7)
4. please post the config of all relevant hosts/guests as well as 'ip a' ,'ip r' and 'ip l'