Networking

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