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Add large community auto-append for standard communities #1

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bd6cbf7
[RS] Auto-append large communities from standard prepend communities
claude May 11, 2026
ae9fad8
[RS] Recognize 65501/65502/65503 large communities for AS-path prepen…
claude May 11, 2026
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54 changes: 48 additions & 6 deletions data/ci/known-good/ci-apiv4-b2-rs1-lan1-ipv4.conf
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Original file line number Diff line number Diff line change
Expand Up @@ -150,23 +150,23 @@ function ixp_community_filter(int peerasn)
return false;

# AS path prepending
if (routeserverasn, 103, peerasn) ~ bgp_large_community then {
if (routeserverasn, 103, peerasn) ~ bgp_large_community || (routeserverasn, 65503, peerasn) ~ bgp_large_community then {
bgp_path.prepend( bgp_path.first );
bgp_path.prepend( bgp_path.first );
bgp_path.prepend( bgp_path.first );
} else if (routeserverasn, 102, peerasn) ~ bgp_large_community then {
} else if (routeserverasn, 102, peerasn) ~ bgp_large_community || (routeserverasn, 65502, peerasn) ~ bgp_large_community then {
bgp_path.prepend( bgp_path.first );
bgp_path.prepend( bgp_path.first );
} else if (routeserverasn, 101, peerasn) ~ bgp_large_community then {
} else if (routeserverasn, 101, peerasn) ~ bgp_large_community || (routeserverasn, 65501, peerasn) ~ bgp_large_community then {
bgp_path.prepend( bgp_path.first );
} else if (routeserverasn, 103, 0) ~ bgp_large_community then {
} else if (routeserverasn, 103, 0) ~ bgp_large_community || (routeserverasn, 65503, 3) ~ bgp_large_community then {
bgp_path.prepend( bgp_path.first );
bgp_path.prepend( bgp_path.first );
bgp_path.prepend( bgp_path.first );
} else if (routeserverasn, 102, 0) ~ bgp_large_community then {
} else if (routeserverasn, 102, 0) ~ bgp_large_community || (routeserverasn, 65502, 2) ~ bgp_large_community then {
bgp_path.prepend( bgp_path.first );
bgp_path.prepend( bgp_path.first );
} else if (routeserverasn, 101, 0) ~ bgp_large_community then {
} else if (routeserverasn, 101, 0) ~ bgp_large_community || (routeserverasn, 65501, 1) ~ bgp_large_community then {
bgp_path.prepend( bgp_path.first );
}

Expand Down Expand Up @@ -340,6 +340,20 @@ int set allas;
# RFC 8326 - facilitate Graceful BGP Session Shutdown
if (65535, 0) ~ bgp_community then bgp_local_pref = 0;

# Auto-append large communities when corresponding standard communities are detected.
# Per-peer variant: a standard community of (65501|65502|65503, peer) gets the
# large community (routeserverasn, 65501|65502|65503, peer) appended.
for pair pc in bgp_community do {
if pc.asn = 65501 then bgp_large_community.add( (routeserverasn, 65501, pc.data) );
if pc.asn = 65502 then bgp_large_community.add( (routeserverasn, 65502, pc.data) );
if pc.asn = 65503 then bgp_large_community.add( (routeserverasn, 65503, pc.data) );
}
# All-peers variant: a standard community of (routeserverasn, 65501|65502|65503) gets
# the large community (routeserverasn, 65501|65502|65503, 1|2|3) appended.
if (routeserverasn, 65501) ~ bgp_community then bgp_large_community.add( (routeserverasn, 65501, 1) );
if (routeserverasn, 65502) ~ bgp_community then bgp_large_community.add( (routeserverasn, 65502, 2) );
if (routeserverasn, 65503) ~ bgp_community then bgp_large_community.add( (routeserverasn, 65503, 3) );

# Filter small prefixes
if ( net ~ [ 0.0.0.0/0{25,32} ] ) then {
bgp_large_community.add( IXP_LC_FILTERED_PREFIX_LEN_TOO_LONG );
Expand Down Expand Up @@ -598,6 +612,20 @@ int set allas;
# RFC 8326 - facilitate Graceful BGP Session Shutdown
if (65535, 0) ~ bgp_community then bgp_local_pref = 0;

# Auto-append large communities when corresponding standard communities are detected.
# Per-peer variant: a standard community of (65501|65502|65503, peer) gets the
# large community (routeserverasn, 65501|65502|65503, peer) appended.
for pair pc in bgp_community do {
if pc.asn = 65501 then bgp_large_community.add( (routeserverasn, 65501, pc.data) );
if pc.asn = 65502 then bgp_large_community.add( (routeserverasn, 65502, pc.data) );
if pc.asn = 65503 then bgp_large_community.add( (routeserverasn, 65503, pc.data) );
}
# All-peers variant: a standard community of (routeserverasn, 65501|65502|65503) gets
# the large community (routeserverasn, 65501|65502|65503, 1|2|3) appended.
if (routeserverasn, 65501) ~ bgp_community then bgp_large_community.add( (routeserverasn, 65501, 1) );
if (routeserverasn, 65502) ~ bgp_community then bgp_large_community.add( (routeserverasn, 65502, 2) );
if (routeserverasn, 65503) ~ bgp_community then bgp_large_community.add( (routeserverasn, 65503, 3) );

# Filter small prefixes
if ( net ~ [ 0.0.0.0/0{25,32} ] ) then {
bgp_large_community.add( IXP_LC_FILTERED_PREFIX_LEN_TOO_LONG );
Expand Down Expand Up @@ -771,6 +799,20 @@ int set allas;
# RFC 8326 - facilitate Graceful BGP Session Shutdown
if (65535, 0) ~ bgp_community then bgp_local_pref = 0;

# Auto-append large communities when corresponding standard communities are detected.
# Per-peer variant: a standard community of (65501|65502|65503, peer) gets the
# large community (routeserverasn, 65501|65502|65503, peer) appended.
for pair pc in bgp_community do {
if pc.asn = 65501 then bgp_large_community.add( (routeserverasn, 65501, pc.data) );
if pc.asn = 65502 then bgp_large_community.add( (routeserverasn, 65502, pc.data) );
if pc.asn = 65503 then bgp_large_community.add( (routeserverasn, 65503, pc.data) );
}
# All-peers variant: a standard community of (routeserverasn, 65501|65502|65503) gets
# the large community (routeserverasn, 65501|65502|65503, 1|2|3) appended.
if (routeserverasn, 65501) ~ bgp_community then bgp_large_community.add( (routeserverasn, 65501, 1) );
if (routeserverasn, 65502) ~ bgp_community then bgp_large_community.add( (routeserverasn, 65502, 2) );
if (routeserverasn, 65503) ~ bgp_community then bgp_large_community.add( (routeserverasn, 65503, 3) );

# Filter small prefixes
if ( net ~ [ 0.0.0.0/0{25,32} ] ) then {
bgp_large_community.add( IXP_LC_FILTERED_PREFIX_LEN_TOO_LONG );
Expand Down
40 changes: 34 additions & 6 deletions data/ci/known-good/ci-apiv4-b2-rs1-lan1-ipv6.conf
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Original file line number Diff line number Diff line change
Expand Up @@ -159,23 +159,23 @@ function ixp_community_filter(int peerasn)
return false;

# AS path prepending
if (routeserverasn, 103, peerasn) ~ bgp_large_community then {
if (routeserverasn, 103, peerasn) ~ bgp_large_community || (routeserverasn, 65503, peerasn) ~ bgp_large_community then {
bgp_path.prepend( bgp_path.first );
bgp_path.prepend( bgp_path.first );
bgp_path.prepend( bgp_path.first );
} else if (routeserverasn, 102, peerasn) ~ bgp_large_community then {
} else if (routeserverasn, 102, peerasn) ~ bgp_large_community || (routeserverasn, 65502, peerasn) ~ bgp_large_community then {
bgp_path.prepend( bgp_path.first );
bgp_path.prepend( bgp_path.first );
} else if (routeserverasn, 101, peerasn) ~ bgp_large_community then {
} else if (routeserverasn, 101, peerasn) ~ bgp_large_community || (routeserverasn, 65501, peerasn) ~ bgp_large_community then {
bgp_path.prepend( bgp_path.first );
} else if (routeserverasn, 103, 0) ~ bgp_large_community then {
} else if (routeserverasn, 103, 0) ~ bgp_large_community || (routeserverasn, 65503, 3) ~ bgp_large_community then {
bgp_path.prepend( bgp_path.first );
bgp_path.prepend( bgp_path.first );
bgp_path.prepend( bgp_path.first );
} else if (routeserverasn, 102, 0) ~ bgp_large_community then {
} else if (routeserverasn, 102, 0) ~ bgp_large_community || (routeserverasn, 65502, 2) ~ bgp_large_community then {
bgp_path.prepend( bgp_path.first );
bgp_path.prepend( bgp_path.first );
} else if (routeserverasn, 101, 0) ~ bgp_large_community then {
} else if (routeserverasn, 101, 0) ~ bgp_large_community || (routeserverasn, 65501, 1) ~ bgp_large_community then {
bgp_path.prepend( bgp_path.first );
}

Expand Down Expand Up @@ -374,6 +374,20 @@ int set allas;
# RFC 8326 - facilitate Graceful BGP Session Shutdown
if (65535, 0) ~ bgp_community then bgp_local_pref = 0;

# Auto-append large communities when corresponding standard communities are detected.
# Per-peer variant: a standard community of (65501|65502|65503, peer) gets the
# large community (routeserverasn, 65501|65502|65503, peer) appended.
for pair pc in bgp_community do {
if pc.asn = 65501 then bgp_large_community.add( (routeserverasn, 65501, pc.data) );
if pc.asn = 65502 then bgp_large_community.add( (routeserverasn, 65502, pc.data) );
if pc.asn = 65503 then bgp_large_community.add( (routeserverasn, 65503, pc.data) );
}
# All-peers variant: a standard community of (routeserverasn, 65501|65502|65503) gets
# the large community (routeserverasn, 65501|65502|65503, 1|2|3) appended.
if (routeserverasn, 65501) ~ bgp_community then bgp_large_community.add( (routeserverasn, 65501, 1) );
if (routeserverasn, 65502) ~ bgp_community then bgp_large_community.add( (routeserverasn, 65502, 2) );
if (routeserverasn, 65503) ~ bgp_community then bgp_large_community.add( (routeserverasn, 65503, 3) );

# Filter small prefixes
if ( net ~ [ ::/0{49,128} ] ) then {
bgp_large_community.add( IXP_LC_FILTERED_PREFIX_LEN_TOO_LONG );
Expand Down Expand Up @@ -556,6 +570,20 @@ int set allas;
# RFC 8326 - facilitate Graceful BGP Session Shutdown
if (65535, 0) ~ bgp_community then bgp_local_pref = 0;

# Auto-append large communities when corresponding standard communities are detected.
# Per-peer variant: a standard community of (65501|65502|65503, peer) gets the
# large community (routeserverasn, 65501|65502|65503, peer) appended.
for pair pc in bgp_community do {
if pc.asn = 65501 then bgp_large_community.add( (routeserverasn, 65501, pc.data) );
if pc.asn = 65502 then bgp_large_community.add( (routeserverasn, 65502, pc.data) );
if pc.asn = 65503 then bgp_large_community.add( (routeserverasn, 65503, pc.data) );
}
# All-peers variant: a standard community of (routeserverasn, 65501|65502|65503) gets
# the large community (routeserverasn, 65501|65502|65503, 1|2|3) appended.
if (routeserverasn, 65501) ~ bgp_community then bgp_large_community.add( (routeserverasn, 65501, 1) );
if (routeserverasn, 65502) ~ bgp_community then bgp_large_community.add( (routeserverasn, 65502, 2) );
if (routeserverasn, 65503) ~ bgp_community then bgp_large_community.add( (routeserverasn, 65503, 3) );

# Filter small prefixes
if ( net ~ [ ::/0{49,128} ] ) then {
bgp_large_community.add( IXP_LC_FILTERED_PREFIX_LEN_TOO_LONG );
Expand Down
12 changes: 6 additions & 6 deletions resources/views/api/v4/router/server/bird2/community-filter.foil.php
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Original file line number Diff line number Diff line change
Expand Up @@ -46,23 +46,23 @@ function ixp_community_filter(int peerasn)

<?php if( $t->router->bgp_lc ): ?>
# AS path prepending
if (routeserverasn, 103, peerasn) ~ bgp_large_community then {
if (routeserverasn, 103, peerasn) ~ bgp_large_community || (routeserverasn, 65503, peerasn) ~ bgp_large_community then {
bgp_path.prepend( bgp_path.first );
bgp_path.prepend( bgp_path.first );
bgp_path.prepend( bgp_path.first );
} else if (routeserverasn, 102, peerasn) ~ bgp_large_community then {
} else if (routeserverasn, 102, peerasn) ~ bgp_large_community || (routeserverasn, 65502, peerasn) ~ bgp_large_community then {
bgp_path.prepend( bgp_path.first );
bgp_path.prepend( bgp_path.first );
} else if (routeserverasn, 101, peerasn) ~ bgp_large_community then {
} else if (routeserverasn, 101, peerasn) ~ bgp_large_community || (routeserverasn, 65501, peerasn) ~ bgp_large_community then {
bgp_path.prepend( bgp_path.first );
} else if (routeserverasn, 103, 0) ~ bgp_large_community then {
} else if (routeserverasn, 103, 0) ~ bgp_large_community || (routeserverasn, 65503, 3) ~ bgp_large_community then {
bgp_path.prepend( bgp_path.first );
bgp_path.prepend( bgp_path.first );
bgp_path.prepend( bgp_path.first );
} else if (routeserverasn, 102, 0) ~ bgp_large_community then {
} else if (routeserverasn, 102, 0) ~ bgp_large_community || (routeserverasn, 65502, 2) ~ bgp_large_community then {
bgp_path.prepend( bgp_path.first );
bgp_path.prepend( bgp_path.first );
} else if (routeserverasn, 101, 0) ~ bgp_large_community then {
} else if (routeserverasn, 101, 0) ~ bgp_large_community || (routeserverasn, 65501, 1) ~ bgp_large_community then {
bgp_path.prepend( bgp_path.first );
}

Expand Down
16 changes: 16 additions & 0 deletions resources/views/api/v4/router/server/bird2/neighbors.foil.php
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Original file line number Diff line number Diff line change
Expand Up @@ -93,6 +93,22 @@
# RFC 8326 - facilitate Graceful BGP Session Shutdown
if (65535, 0) ~ bgp_community then bgp_local_pref = 0;

<?php if( $t->router->bgp_lc ): ?>
# Auto-append large communities when corresponding standard communities are detected.
# Per-peer variant: a standard community of (65501|65502|65503, peer) gets the
# large community (routeserverasn, 65501|65502|65503, peer) appended.
for pair pc in bgp_community do {
if pc.asn = 65501 then bgp_large_community.add( (routeserverasn, 65501, pc.data) );
if pc.asn = 65502 then bgp_large_community.add( (routeserverasn, 65502, pc.data) );
if pc.asn = 65503 then bgp_large_community.add( (routeserverasn, 65503, pc.data) );
}
# All-peers variant: a standard community of (routeserverasn, 65501|65502|65503) gets
# the large community (routeserverasn, 65501|65502|65503, 1|2|3) appended.
if (routeserverasn, 65501) ~ bgp_community then bgp_large_community.add( (routeserverasn, 65501, 1) );
if (routeserverasn, 65502) ~ bgp_community then bgp_large_community.add( (routeserverasn, 65502, 2) );
if (routeserverasn, 65503) ~ bgp_community then bgp_large_community.add( (routeserverasn, 65503, 3) );

<?php endif; ?>
# Filter small prefixes
<?php if( $t->router->protocol == 6 ): ?>
if ( net ~ [ ::/0{<?= config( 'ixp.irrdb.min_v6_subnet_size', 48 ) == 128 ? 128 : config( 'ixp.irrdb.min_v6_subnet_size', 48 ) + 1 ?>,128} ] ) then {
Expand Down