Network/Renumbering

From NURDspace

Introduction

We need to renumber the network to reduce the latency spikes we see every now and then. The working theory is that, during network load, and because of the roundtrips on traffic between different subnets, and based on the drops in all gateway graphs in icinga, that the cpu of the edgerouter is occasionally at its limits, causing packetloss and high-latency.

To fix this, the network will be renumbered into a single subnet. This should be done in a least disruptive manner as possible

New numberplan

Subnet: 10.208.0.0/22 Netmask: 255.255.252.0

Segment Purpose
10.208.0.[1..254] network devices
10.208.1.[1..254] servers
10.208.[34].[1..254] clients / dhcp

Renumbering procedure

This is only for servers; Everything in the dhcp range will be managed by changing the dhcp start/end addresses. Note that we will need to check if devices in the dhcp range are configured with a static ip and if so, we need to reconfigure them to dhcp and fix their ip address in dhcp.

  1. Preparation
    1. Make inventory of 10.208.10.0/24
    2. Make inventory of 10.208.11.0/24
    3. Make inventory of 10.208.20.0/24
    4. Make inventory of 10.208.30.0/24
    5. Add 10.208.0.1/22 as an ip address on the gateway
  2. Execution (for each server host)
    1. Find new ip address in correct segment
    2. Configure new ip address as a primary ip
    3. Configure the old ip as a secondary ip
    4. Reconfigure DNS
  3. Migration of servers (this is done on a host-by-host basis)
    1. Watch for incoming traffic on the old ip address
    2. Find out which device is connected to the source ip's
    3. Reconfigure these devices to connect to the new ip (preferrably via dns)
    4. Repeat until no traffic arrives on old ip address
    5. Remove old ip address from server
  4. Migration of clients
    1. Reconfigure clients that have a static ip to receive that from the new dhcp range & reconfigure the devices for dhcp
    2. Set the dhcp range to 10.208.2.1 .. 10.208.3.254
  5. Finalize configuration
    1. Cleanup all traces of 10.208.10.0/24
    2. Cleanup all traces of 10.208.11.0/24
    3. Cleanup all traces of 10.208.20.0/24
    4. Cleanup all traces of 10.208.30.0/24


TODO: add ip address inventories and tables for managing and administering stuff