Seabone makes use of some set of communities to help our customers to better tune their traffic without requiring a manual intervention from us.
All customers are allowed to send the following communities:
This community string implementation is used to permit our customers to control their announcements towards the largest peerings.
The format is 6762:40pXX where the fields are coded in the following way:
p if 0 do not announce this prefix to XX, if 1,2 or 3 prepend network 1, 2 or 3 times to XX
XX defines the network you don't want to send this route to, according to the following table:
The same scheme above is now extended so as to permit the customers to do selective announcements to the public peering points to which Seabone is connected.
The format is 6762:400XX where the fields are coded in the following way:
XX defines the IXP you don't want to send this route to, according to the following table:
The standard local preferences on Seabone are defined as 100 for customer Routes and 90 for peering routes.
A local preference of 50 is used for backup routes, such as when confining a route in a region.
This prevents the creation of blackholes in case a better route to destination is not learnt in other regions for any reason.
Customer can modify the local preference for their routes by sending a community 6762:1xxx. The following table shows the available values:
|6762:1090||Set local preference to 90 (same as peering)|
|6762:1070||Set local preference to 70 (lower than peering)|
|6762:1050||Set local preference to 50 (backup route)|
This scheme works only for peers that Seabone reaches over the public switch fabric. It is not implemented for private peers even if they are on the same router, nor for peers with a hybrid setup (private and public).
All customers will receive at least one of these communities. These communities will help you to choose the routes that you receive from Seabone, if you have the need to route only to a particular area, or if you want to treat your link as a peering link.
|6762:30||Route learnt in Europe|
|6762:31||Route learnt in North-America|
|6762:32||Route learnt in South-America|
|6762:33||Route learnt in Asia|
|6762:34||Route learnt in Africa|
|6762:60||Route learnt from a customer|
The distinction on geographic area is based on where the route entered Seabone's network. This means that you should not be surprised of seeing, for example, a South American customer tagged as North American.