Elisa IP Transit technical details

ROUTING POLICY


This is how our routing works:

  • We usually announce our own routes summarized the way that we received the IP blocks from Réseaux IP Européens.
  • We announce our AS customers' routes the way they announce them to us, unless the customer requests proxy aggregation. We will make effort to ensure that the customers' routes are efficiently aggregated though. We also take protective measures to prevent harm originating from our customers to the global routing system.
  • We do not redistribute our IGP into BGP (nor do we redistribute BGP into the IGP.)
  • We follow RIPE's dampening regulations thus we do not damp routes.
  • We will filter routes and traffic to illegal destinations such as IANA reserved networks. We won't accept traffic that should originate from within our own network. We protect ourselves from over specific routes and accept them only on a case by case basis. Please refer to our other documents about filtering etc.
  • Our AS at all exchanges is AS6667 and we announce the ASes listed in the Réseaux IP Européens AS macros AS-EUNETIP and RS-EUNETIP.

ROUTE AND PACKET FILTERING

 
AS6667 filters routes considered harmful at the border. These can be of the following types:
 
  • Our own IP blocks
  • IANA reserved IP blocks
  • Prefixes longer than /24 (netmask 255.255.255.0)
  • Prefixes longer than /22 (netmask 255.255.248.0)
 
We will never accept prefixes more specific than /24. We will always accept /24 routes within The Swamp (192.0.0.0/7). Outside that range the default filter will get rid of prefixes longer than /22.
 
If a peer's routes are otherwise well behaved, but they have a few legitimate routes that would get caught by the default filter, we will use a more lenient filter. Should we ever give a peer subnets from our own CIDR allocations (such as if a customer with a large continuous chunk of address space moved to another provider), there's also a filter that lets almost anything through.
 

BGP COMMUNITIES


These communities are recognized and used by AS6667
COMMUNITYEFFECT
6667:80
Set LOCAL_PREF to 80
6667:90
Set LOCAL_PREF to 90
6667:100
Set LOCAL_PREF to 100
6667:110
Set LOCAL_PREF to 110
NOTE: These communities will evolve with changes in transit providers and exchange points. If you are having problems with the communities, check here first to see if a community has been changed or removed. We will try to not change the meaning of a community unless the new meaning is a direct replacement.

LOCAL PREFERENCE

 
The communities that set the local preference within our network are usable by all customers and peers. The default local preference for customers is 101 and for peers it is 100. The default local preference for transits is 90. Local preference of 80 is meant for backup provided by a customer or peer to someone else and the local preference of 110 is meant for overriding routing to choose a certain path over others. Peers can't set a preference of 110.

ANNOUNCE ROUTE

 
The communities that control route announcement to peers and transits are only available to customers. The x specifies what the action for the said target is:
0 Announce as is ..
1 Announce with 6667 prepended to as-path ...
2 Announce with 6667 6667 prepended to as-path ...
3 Announce with 6667 6667 6667 prepended to as-path ...
9 Don't announce ... (default and takes precedence if present)
We will also let external communities through from customers. This will enable customers to use similar communities of our peers and transits. Some pages describing these communities have been collected at the end of the page.
COMMUNITYEFFECT
6667:90x
to all AS6667 customers
6667:100x
to all transits
6667:101x
to AS3356 CenturyLink
6667:102x
to AS174 Cogent
6667:107x
to AS3257 GTT Communications
6667:109x
to AS1299 TSIC
X:200x
to all peers
X:201x
to peers in Helsinki Finland and at Ficix
719:202x
to peers in Tampere Finland
790:202x
to peers in Tampere Finland
6667:202x
to peers in Stockholm Sweden and at Netnod-stockholm (Netnod)
6667:203x
to peers in London UK and at LINX
6667:204x
to peers in Frankfurt Germany and at DECIX
6667:206x
to peers in Copenhagen Denmark and at DIX
6667:207x
to peers in Oslo Norway and at NIX
6667:208x
to peers in Amsterdam Netherlands and at AMSIX
6667:209x
to peers in New York USA and at NYIIX
6667:210x
to peer AS8359 (Comstar)
6667:211x
to peer AS3249 (Elion)

ROUTE ORIGINS


These communities are tagged on all routes to distinguish their origins. They are sent to everyone but not excepted from outside. They are there to let customers filter routes based on route source. Standard customers announce all their routes to us with communities 6667:900, 6667:1000 and 6667:2000. When Elisa receives the routes, they are tagged with 6667:300x and the local location community (6667:4xxx.).

COMMUNITYEFFECT
X:3000
Internal or customer
X:3001
Public peering
X:3003
Private peering
X:3004
Transit
X:4000
Tampere, Finland
X:4001
Turku, Finland
X:4002
Helsinki, Finland
X:4003
Oulu, Finland
6667:4003
Stockholm, Sweden
6667:4004
London, United Kingdom
6667:4005
Frankfurt, Germany
6667:4007
Copenhagen, Denmark
6667:4008
Oslo, Norway
6667:4009
Amsterdam, The Netherlands
6667:4010
New York, United States
6667:4011
Tallinn, Estonia

PEERING POLICY


If you are interested in peering, please contact peering(at)elisa.fi.