Netnod IX technical information

Netnod IX technical information

Swedish national Internet exchange points are built on Ethernet technology. It is a layer 2 service with no routing facilities existing within the exchange points. The connected ISP's routers are responsible for the routing of packets through the exchange points. Netnod internet exchange points currently exist in Stockholm, Gothenburg, Copenhagen/Malmö, Sundsvall and Luleå.

Common  Switching Equipment

In Stockholm the exchange points consists of two large Ethernet switches located in two main safe facilities operated by Netnod. There are also a couple of co-location sites where Netnod has either switches or DWDM-equipment to backhaul traffic to the two main sites.

All of the installed infrastructure equipment has redundancy to protect from electrical breakdown for high reliability demands. The main sites are called STH-A and STH-B. There is no direct connection between the switches in the different locations. The switches and other common equipment are physically protected according to current rules and recommendations from the Swedish regulator (PTS). The exact locations of the two main sites are not published. 

In Stockholm Netnod also have on-site presence on the larger commercial co-location-sites. On those sites two local cross-connects are needed to connect. These sites also have a high degree of physical access-safety, redundant power and fire suppression. 

In Gothenburg, Malmö, Sundsvall and Luleå the exchange point consists of one switch located in a safe facility, operated by Netnod. All installed infrastructure equipment has redundancy from electrical breakdown for high reliability demands. The two sites in Copenhagen that are, together with VG4 and NNB, form Netnod IX Copenhagen are located at commercial colocation companies. These sites also have a high degree of physical access-safety, redundant power and firesuppresion.

Technical description

In Gothenburg, Sundsvall and Luleå the exchange points are single, standalone, non- interconnected switches. 
In Copenhagen/Malmö the switches on the five different sites are interconnected creating a distributed exchange point.
In Stockholm there are two standalone, non-interconnected switches. 

Network connections in Stockholm

There are two ways to connect to the switch fabrics in Stockholm: 
1. Two separate single mode fibre-optic cables, provided by Netnod, connect the two switches with the address/addresses of the ISP.
2. Two on-site connections at the data centers where Netnod is present throught the datacenter Meet Me Rooms (MMRs).

MAC addresses

The ports on the switches will be configured to allow only the connected customers' interface-MAC-addresses. The MAC adresses of the customers' interfaces need to be provided to Netnod in advance.


The exchange points consist of two different VLANs on each main switch. One VLAN handles standard-sized ethernet frames (MTU <1500 bytes) and one handles Ethernet Jumbo frames with MTU-size 4470 bytes. The VLANs are implemented according to IEEE802.1Q. The VLAN supporting 1500 bytes MTU is VLAN #215 and the VLAN for MTU-size 4470 is VLAN #216 on STH-A. For STH-B the VLAN supporting 1500 bytes MTU is VLAN #15 and VLAN for MTU-size 4470 is VLAN #16. The customer has to decide which MTU-size to be used, so as to connect to the correct VLAN. As there is no connection within the exchange points between the different VLANs, a customer that communicates with parties using different MTU-sizes MUST have a connection to each VLAN.

IP addresses

All Netnod exchange points support IPv4 and IPv6. There are up to four different IP networks used on each switch-fabric, two for IPv4 (MTU 1500 and MTU4470) and two for IPv6 (MTU1500 and MTU4470). This means that in Stockholm there are 8 IP-networks available in total. Netnod will assign and distribute IP addresses to the connected customers.

Unicast traffic

Peering between an ISP'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.


Netnod operates route servers at the Stockholm IX as well as the Copenhagen exchange point (Copenhagen-Malmö). 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.

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.

This is the list of colocation providers in Stockholm, Copenhagen, Malmö and Göteborg.

Transport network suppliers and fibre suppliers for connecting in Göteborg, Malmö and Sundsvall.

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

All traffic statistics for the Netnod Internet exchange points are publicly available.
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