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.