Netnod’s IXP Architecture

This page explains the technical setup at Netnod IXes and provides important connection details for customers.

Technical overview

Netnod’s Internet exchange points are built on Ethernet technology. They are a layer 2 service with no routing facilities existing within the exchange points.

For customers connecting to Netnod at a data centre, one cross connect is needed per port. If you order a redundant connection in Stockholm, Copenhagen or Helsinki (see below), you will need two cross connects. In that case, you will be guaranteed diverse paths to ensure redundancy.

Redundant ports vs single port

At the Netnod IXes in Stockholm, Copenhagen and Helsinki, the IX has two redundant peering fabrics located in separate, secure sites. There are also a number of co-location sites with switches and DWDM equipment to backhaul traffic to the two main sites. The switch fabrics in these metros use a dedicated fibre path for each switch to ensure multiple, redundant paths.

Customers at the IXes in Stockholm, Copenhagen and Helsinki can buy a redundant connection which gives them two ports connected to the separate switch fabrics on the Internet Exchange. These switch fabrics are labelled “Green” and “Blue”.

As you can see below, Network A has redundant ports and connects to the Blue peering fabric with one port and to the Green peering fabric with a second port. Networks B and C use a single connection over a single port to connect to the Blue AND Green peering LANs.

How does redundancy work at the Netnod IX?

The Netnod IXes in Gothenburg, Sundsvall, and Luleå do not currently have physical redundancy as an option. However, if there is customer demand, Netnod will add redundant switches to any of our IXes.

MAC addresses

The ports on the peering LAN will be configured to allow only the connected customers' interface-MAC-addresses. The MAC addresses of the customer's interfaces need to be provided to Netnod in advance. In case of a change in the customer's hardware, Netnod needs to be notified at least one full working day in advance.

IP addresses

All Netnod IXes support IPv4 and IPv6. Each VLAN connection should always have one of each.

The amount of IP addresses needed for each customer depends on two things: if the exchange is redundant and the MTU/VLAN setup on the peering LAN.

Netnod will assign and distribute IP addresses to the connected customers.

MTU/VLAN setup

Currently there are 2 standard setups:

Type:

MTU 9000 only peering VLAN per peering LAN (1 IPv4 + 1 IPv6)
MTU 1500 + MTU 4470 peering VLANs per peering LAN ( 2 IPv4 + 2 IPv6)

If the exchange is Redundant each peering LAN is configured with either 1 or 2 VLANs per peering LAN according to the two types shown above.

The VLANs are implemented according to IEEE802.1Q. As there is no connection within the exchange points between the different VLANs, a customer that communicates with parties using different MTU-sizes needs to have a connection to each VLAN they want to exchange traffic on.

Summary of MTU/VLAN setup at Netnod IXes

Exchange Location	Available VLANs	MTU-size(s)	Redundancy possible
Stockholm	BLUE GREEN	1500+4470 1500+4470	Yes
Copenhagen	BLUE GREEN	9000 9000	Yes
Helsinki	BLUE GREEN	9000 9000	Yes*
Gothenburg	BLUE	1500+4470	No
Sundsvall	BLUE	1500+4470	No
Luleå	BLUE	1500+4470	No

*Customers who need local redundancy in Helsinki are advised to connect to HE7

Setup in Stockholm:

VLAN setup Stockholm

Setup in Copenhagen:

VLAN setup Copenhagen

Setup in Helsinki:

Helsinki

Setup in Gothenburg:

VLAN setup Gothenburg

Setup in Sundsvall:

VLAN setup Sundsvall

Setup in Luleå:

VLAN Setup Lulea

Unicast traffic

Peering between a customer’s routers through the exchange point will be done via BGP4. Any kind of tunneling is explicitly forbidden.

Multicast traffic

Multicast traffic is supported over the exchange points.

Route servers

A route server facilitates the administration of peering arrangements for networks present at an exchange point. By connecting to the route server, you can replace some or all of your separate BGP sessions to your peers, with one single session towards the route server.

Router configuration examples

Here are example configurations that illustrates a router connected to both of the VLANs on the STH-B switch. The VLAN ids will be different for other Netnod IX's. The examples are only examples and will most likely need to be adopted to your environment and platform.

IX Technical info

Usage policy

This page summarises the usage and connection policy at the Netnod Internet Exchange.

IX FAQ

Here we answer some of the most common questions about peering, IXPs and Netnod IX.

Educational resources

What is peering?

Peering allows multiple networks to connect and exchange traffic. Find out how peering helps cut costs and increase the resilience, speed and performance of networks. This peering overview explains the different types of peering arrangements and what you need to do to get started.

Educational resources

What is interconnection?

Any company doing digital business needs an IT strategy that ensures network security, reach and performance. Interconnection plays a key role here. The right interconnection strategy grows your network, saves costs and provides the flexibility to scale and guarantee high-performing services.

Connected networks at Netnod IX

Learn more