Netnod’s IXP Architecture
Technical overview
In Stockholm the exchange point consists of two redundant peering LANs located in two main safe facilities operated by Netnod. There are also a couple of co-location sites where Netnod has switches and 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 two peering networks are labelled “Green” and “Blue”. Netnod has two core sites in Stockholm where the switches and other common equipment are physically protected according to current rules and recommendations from the Swedish regulator (PTS). The exact locations of these sites are not published.
For customers connecting to Netnod at a data centre, one or two local cross-connects are needed to connect. One for single-port and two for a redundant connection. If a redundant connection is ordered Netnod will ensure that the paths will be diverse.
In Gothenburg, Malmö, Sundsvall and Luleå the exchange point consists of one peering network 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, together with VG4 and NNB, form Netnod IX Copenhagen are located at data centres. These sites also have a high degree of physical access-safety, redundant power and fire suppression.
Technical description
In Gothenburg, Sundsvall and Luleå the exchange points are single, standalone, non-interconnected switches.
In Stockholm and Copenhagen the exchange points are built in a redundant manner providing the possibility of connecting to both the “Green” and “Blue” peering networks (Netnod IX Redundant). There is also the possibility of connecting to both peering networks over a single port (Netnod IX Single Port). The networks will then be provided in tagged VLANs on the same physical customer port.
Network connections in Stockholm
There are two ways to connect to the peering LANs in Stockholm:Netnod on-net locations
If the customer is present at an on-net location where Netnod has an established presence, the customer only needs to order a cross-connect.Netnod off-net locations
If the customer wants to connect from an off-net location, the cost for the access fibre will be added.
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 need to be notified at least one full working day in advance.
IP addresses
All Netnod exchange points 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 (as in Stockholm and Copenhagen) each peering LAN is configured with either 1 or 2 VLANs per peering LAN according to the two types shown above.
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 |
*You need to connect to two sites for full redundancy
Setup in Stockholm:
Setup in Copenhagen:
Setup in Gothenburg:
Setup in Sundsvall:
Setup in Luleå:
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.
Redundant Ports vs Single Port
In the exchange points that have both a Blue and a Green Network, a fully redundant setup is possible (currently Stockholm and Copenhagen). As can be seen in the picture below Customer A has redundant connections and connects to the Blue network with one physical link/interface and to the Green network with a second physical link/interface. Customer B and C use single connections and will connect to the Blue AND Green Networks via a single physical link/interface.
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.