These are the communities we carry in iBGP. Communities in blue are sent to customers who have requested send-community. Communities in black are accepted from customers to influence routing policy.

Communities
Description Origination 1 Prepend 2 Prepends 3 Prepends Do not advertise
Transit 42579:1000 42579:10001 42579:10002 42579:10003 42579:10009
Transit - UK 42579:1001 42579:10011 42579:10012 42579:10013 42579:10019
Transit - USA 42579:1002 42579:10021 42579:10022 42579:10023 42579:10029
Transit - NTT 42579:1101 42579:11011 42579:11012 42579:11013 42579:11019
Transit - Datahop 42579:1102 42579:11021 42579:11022 42579:11023 42579:11029
Transit - Atlantic Metro 42579:1103 42579:11031 42579:11032 42579:11033 42579:11039
Transit - Level3 42579:1104 42579:11041 42579:11042 42579:11043 42579:11049
Public Peering 42579:2000 42579:20001 42579:20002 42579:20003 42579:20009
Public Peering - NYCx 42579:2001 42579:20011 42579:20012 42579:20013 42579:20019
Public Peering - LINX 42579:2002 42579:20021 42579:20022 42579:20023 42579:20029
Public Peering - LONAP 42579:2003 42579:20031 42579:20032 42579:20033 42579:20039
Public Peering - BigAPE 42579:2004 42579:20041 42579:20042 42579:20043 42579:20049
Private Peering 42579:3000 42579:30001 42579:30002 42579:30003 42579:30009
Customer 42579:4000
Customer - lsrei01 42579:4001
Customer - lsmit01 42579:4002
Customer - lnpop01 42579:4003
Customer - lnpop02 42579:4004
Customer - clbis02 42579:4005
Sargasso originated 42579:5000
Sargasso originated - lsrei01 42579:5001
Sargasso originated - lsmit01 42579:5002
Sargasso originated - lnpop01 42579:5003
Sargasso originated - lnpop02 42579:5004
Sargasso originated - clbis02 42579:5005
Description Increase Normal Decrease
Influence localpref 42579:10 42579:11 42579:12
Description Community
Announce (Sargasso+customer) 42579:501
Blackhole route 42579:666

Each route also carries a local preference. The following are common examples:

Local Preference
localpref Description
160 Preferred customer or internal
150 Standard customer or internal
140 De-prefed customer or internal
130 Preferred private peer
120 Standard private peer
110 De-prefed private peer
100 Preferred public peer
90 Standard public peer
80 De-prefed public peer
70 Preferred transit
60 Standard transit
50 De-prefed transit