BGP Community questions

Jan Czmok czmok at
Fri Jan 16 13:41:21 UTC 1998

I have a question regarding BGP Community. How can this be done ?

remarks:     Community    Definition
remarks:     1755:666     Route received from other provider with
remarks:     agreement with EBONE.
remarks:     1755:667     Route received from Sprint/ICM.

That is clear, they do a match against the AS Num and set community 666
and 667
remarks:     Communities to control traffic (settable by RBSes).
remarks:     Community    Definition
remarks:     1755:1000    No ICM(US) announcement of route
remarks:     1755:1001    Backup through ICM
remarks:     1755:1100    No DIGEX(US) announcement of route
remarks:     1755:2000    No announcement to european peers
remarks:     1755:2001    Prepend to path when announcing to european

how is this done ?

int xxx
ip access-group community-list 10 out

ip community-list 10 deny 1755:2000
ip community-list 10 ?????????????

whats the permit rule for that?

remarks:     1755:2101    Do not announce to EUnet      (AS286)
remarks:     1755:2102    Do not announce to IBM GN     (AS2686)
remarks:     1755:2103    Do not announce to RIPE NCC   (AS3333)
remarks:     1755:2104    Do not announce to BT         (AS5400)
remarks:     1755:2105    Do not announce to AUCS       (AS3300)
remarks:     1755:2106    Do not announce to UUNET      (AS702)
remarks:     1755:2107    Do not announce to Compuserve (AS5621)
remarks:     1755:2201    Prepend when announcing to EUnet      (AS286)
remarks:     1755:2202    Prepend when announcing to IBM GN     (AS2686)

remarks:     1755:2203    Prepend when announcing to RIPE NCC   (AS3333)

remarks:     1755:2204    Prepend when announcing to BT         (AS5400)

remarks:     1755:2205    Prepend when announcing to AUCS       (AS3300)

remarks:     1755:2206    Prepend when announcing to UUNET      (AS702)
remarks:     1755:2207    Prepend when announcing to Compuserve (AS5621)

the prepend stuff is clear

Many thanks for help


Jan Czmok

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