Mystical network problems.

[webak]

Proxmox 8.1.10. The server is located at hetzner. For two nights in a row, the server has lost Internet access. Rebooting doesn't help. Only the *service networkmanager restart* helps - through KVM. Where to dig into the solution of the problem?

/etc/network/interfaces
# network interface settings; autogenerated
# Please do NOT modify this file directly, unless you know what
# you're doing.
#
# If you want to manage parts of the network configuration manually,
# please utilize the 'source' or 'source-directory' directives to do
# so.
# PVE will preserve these directives, but will NOT read its network
# configuration from sourced files, so do not attempt to move any of
# the PVE managed interfaces into external files!

source /etc/network/interfaces.d/*

auto lo
iface lo inet loopback

iface lo inet6 loopback

auto enp193s0f0np0
iface enp193s0f0np0 inet manual
# address 142.xx.xx.253/26
# gateway 142.xx.xx.193
# up route add -net 142.xx.xx.192 netmask 255.255.255.192 gw 142.xx.xx.193 dev enp193s0f0np0
# route 142.xx.xx.192/26 via 142.xx.xx.193

iface enp193s0f1np1 inet manual

iface enxb68244e54cdd inet manual

auto vmbr0
iface vmbr0 inet static
address 142.xx.xx.253/25
gateway 142.xx.xx.193
bridge-ports enp193s0f0np0
bridge-stp off
bridge-fd 0
# up route add -net 142.xx.xx.192 netmask 255.255.255.192 gw 142.xx.xx.193 dev enp193s0f0np0

auto vmbr2
iface vmbr2 inet static
address 192.168.0.1/24
bridge-ports none
bridge-stp off
bridge-fd 0
post-up echo 1 > /proc/sys/net/ipv4/ip_forward
post-up iptables -t nat -A POSTROUTING -s '192.168.0.1/24' -o vmbr0 -j MASQUERADE
post-down iptables -t nat -D POSTROUTING -s '192.168.0.1/24' -o vmbr0 -j MASQUERADE