Network/Renumbering

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..255]	network devices
10.208.1.[0..255]	servers
10.208.[23].[0..254]	clients / dhcp

Gateway: 10.208.0.1

DNS: 10.208.1.53

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

10.208.10.0/24

Range is empty, yay

10.208.11.0/24

IP	Host	Device type	New IP	Reconfigured?	Notes
10.208.11.1	gw.vm.nurd.space	network	10.208.0.1
10.208.11.2	wekan.vm.nurd.space	server	10.208.1.1	Yes
10.208.11.4	auth.vm.nurd.space	server	10.208.1.2	Yes
10.208.11.6	revproxy01.vm.nurd.space	server	10.208.1.3	Yes	Old machine, take special care
10.208.11.7	gitea.vm.nurd.space	server	10.208.1.4	Yes
10.208.11.8	docker.vm.nurd.space	server	10.208.1.5	Yes
10.208.11.10	parts.vm.nurd.space	server	10.208.1.6	Yes
10.208.11.11	soundfx.vm.nurd.space	server	10.208.1.7	Yes
10.208.11.13	asterisk.vm.nurd.space	server	10.208.1.8	Yes
10.208.11.26	portal.vm.nurd.space	server	10.208.1.9	Yes
10.208.11.30	jarvis2.vm.nurd.space	server	10.208.1.10	TODO: weird ip config	Forgotten migration project?
10.208.11.31	influx.vm.nurd.space	server	10.208.1.11	Yes
10.208.11.32	jarvis.vm.nurd.space	server	10.208.1.12	TODO: weird ip config
10.208.11.42	ipam.vm.nurd.space.	server	10.208.1.13	Yes
10.208.11.111	ldap-dev.vm.nurd.space	server	10.208.1.14	Yes	still used??
10.208.11.210	postgresql.vm.nurd.space	server	10.208.1.15	Yes
10.208.11.250	egg.vm.nurd.space	server	10.208.1.16	Yes	NAT rules on gateway

10.208.20.0/24

Range is empty, yay

10.208.30.0/24

IP	Host	Device type	New IP	Reconfigured?	Notes
10.208.30.1	gateway.lan.nurd.space	network	10.208.0.1
10.208.30.2	core-sw.lan.nurd.space	network	10.208.0.2	Yes
10.208.30.3	zaal1-sw.lan.nurd.space	network	10.208.0.3	Yes
10.208.30.4	slabpi.lan.nurd.space	server	10.208.1.17	Yes
10.208.30.6	backup.vm.nurd.space	server	10.208.1.18	Yes
10.208.30.7	sdr.vm.nurd.space	server	10.208.1.19	Yes
10.208.30.10	ticktack.lan.nurd.space	server	10.208.1.20
10.208.30.11	librenms.vm.nurd.space	server	10.208.1.21	Yes
10.208.30.18	webmpd.vm.nurd.space	server			removed
10.208.30.19	spacesound.vm.nurd.space	server	10.208.1.23	Yes
10.208.30.21	zaal1-ap.lan.nurd.space	network	10.208.0.3	Yes
10.208.30.24	gpu.vm.nurd.space	server	10.208.1.24	Yes
10.208.30.40	mongodb.vm.nurd.space	server	10.208.1.25	Yes
10.208.30.60	harmony.lan.nurd.space	server	10.208.1.26	Yes
10.208.30.66	nurdwiki-migration.lan.nurd.space	server		will not be migrated
10.208.30.67	harkbot.vm.nurd.space	server	10.208.1.27	Yes
10.208.30.68	ticker-proxy.vm.nurd.space	server	10.208.1.28	Yes
10.208.30.70	erratic.lan.nurd.space	server	10.208.1.29	Yes
10.208.30.71	erratic-bmc.lan.nurd.space	server	10.208.1.30	Yes
10.208.30.100	xmpp.vm.nurd.space	server	10.208.1.31	Yes
10.208.30.101	monitor.vm.nurd.space	server	10.208.1.32	Yes
10.208.30.110	ipfixer.lan.nurd.space	server	10.208.1.33
10.208.30.111	iptv-server.lan.nurd.space	server	10.208.1.34	Yes
10.208.30.150	pdu01.lan.nurd.space	server	10.208.1.47	Yes
10.208.30.152	epc2.lan.nurd.space	server	10.208.1.44	Yes
10.208.30.153	epc3.lan.nurd.space	server	10.208.1.45	Yes
10.208.30.154	epc4.lan.nurd.space	server	10.208.1.46	Yes
10.208.30.188	minecraft.vm.nurd.space	server	10.208.1.39	Yes
10.208.30.222	lora-gateway.lan.nurd.space	server	10.208.1.40
10.208.30.254	nurdservices.lan.nurd.space	server	10.208.1.42, 10.208.1.53	Yes	Maybe use this alias for DNS?

Reconfiguring a server

Modify the network configuration

/etc/network/interfaces

vi /etc/network/interfaces

Modify the contents to the following:

address <new ip address>/22
gateway 10.208.0.1
post-up ip addr add <old ip address>/24 dev eth0

NetworkManager

nmcl connection edit <interface>
set ipv4.addresses <new ip address>/22
set ipv4.gateway 10.208.0.1
save persistent

Netplan

vi /etc/netplan/00-installer-config.yaml

• Add new ip address under network.ethernets.<network card>.addresses
• Change the default route to point to 10.208.0.1

Apply the configuration without rebooting

Login to the server via gateway.lan.nurd.space (you need to be in a directly attached subnet for the server for this step)

ip addr add <new ip address>/22 dev <network card> && ip route delete default && ip route add default via 10.208.0.1