Networking Service

Infrastructure

each server is connected to two top of the rack switches by 2x10G
connections are configured as redundant, active/active Layer 2 & 3 Setup (MLAG/VARP)
we make heavy usage of VLANs to seperate customer segements
all our servers and services are reachable by IPv4 and IPv6. Details are available at Dualstack IPv4/IPv6.

Configuration

all servers are setup with sane defaults, usually you dont have to worry about network configuration
for special cases, you can add the following settings

{
  "networking::interfaces": {
    "eth0": {
      "address": "99",
      "address_prefix_v4": "192.168.0",
      "netmask_v4": "255.255.255.0",
      "gateway_v4": "192.168.0.1",
      "address_prefix_v6": "2001:db8::",
      "netmask_v6": "64",
      "gateway_v6": "2001:db8::1"
    }
  }
}

this will led to the following Network Configuration

auto eth0
    iface eth0 inet static
    address 192.168.0.99
    netmask 255.255.255.0
    gateway 192.168.0.1

    iface   eth0 inet6 static
    address 2001:db8::99
    netmask 64
    gateway 2001:db8::1

usually, you only have to configure the “address” parameter. All other settings should get the appropriate value trough inheritance
by replacing eth0 with ethX, you can add additional interfaces in the same or other subnets
as both IPv4 and IPv6 is configured manually, we disable IPv6 autoconf and router advertisement