what is the purpose of network on eth0?

Posted May 9, 2018 3.6k views
SecurityNetworkingFirewallUbuntu 18.04

while configuring firewall rules for a new (ubuntu 18.04 in nyc3) droplet today, i noticed that the output of route (below) shows three networks instead of the normal two (public, private).

can anyone tell me why the network exists in our droplets? - public - private - ???

root@104:~# route
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
default         _gateway         UG    0      0        0 eth0     U     0      0        0 eth0     U     0      0        0 eth1   U     0      0        0 eth0


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4 answers

Are you using any floating IPs or a load balancer with your droplet? Floating IPs will appear as another local network interface rather than an interface with the public floating ip shown.

Thanks for the speedy reply ryanpq!

Nope, it’s just a basic droplet with private networking, so no floating IPs or load balancing. Also no backup plan, monitoring, cloud-firewall or IPv6.

ok. got it. thanks!

so apparently, even when a droplet has no floating ip enabled at the time of it’s creation, the anchor ip will be configured for the droplet regardless, to ease the process of enabling floating ip at a later time.