What do the network rules in SolusIO > Settings > Network Rules mean?
Enable ARP flood protection - This rule prevents ARP flood attacks and prevent IP stealing
Disable DHCP traffic - prevent DHCP traffic(the VPS cannot act as DHCP server) by blocking connections on ports 67 and 68.
Disable cloud-init server access - blocks connection from the network 169.254.0.0/16 used by Cloud-init metadata agent. This does not allow any cloud-init(other than SolusIO) instance to manage the VPS.
Disable SMTP traffic - blocks connection on ports 25, 465, 587
Disable ICMP traffic - blocks any incoming icmp traffic(ping)
Disable ICMP reply traffic - blocks outgoing ICMP response packets(ping reply)
Disable RPC Portmapper ports - blocks outgoing TCP port 111