diff --git a/data/ci/known-good/ci-apiv4-b2-rs1-lan1-ipv4.conf b/data/ci/known-good/ci-apiv4-b2-rs1-lan1-ipv4.conf
index ed08b6ffe..a770a2735 100644
--- a/data/ci/known-good/ci-apiv4-b2-rs1-lan1-ipv4.conf
+++ b/data/ci/known-good/ci-apiv4-b2-rs1-lan1-ipv4.conf
@@ -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 );
     }
 
@@ -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 );
@@ -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 );
@@ -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 );
diff --git a/data/ci/known-good/ci-apiv4-b2-rs1-lan1-ipv6.conf b/data/ci/known-good/ci-apiv4-b2-rs1-lan1-ipv6.conf
index 35fc3a24b..b6deed3d3 100644
--- a/data/ci/known-good/ci-apiv4-b2-rs1-lan1-ipv6.conf
+++ b/data/ci/known-good/ci-apiv4-b2-rs1-lan1-ipv6.conf
@@ -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 );
     }
 
@@ -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 );
@@ -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 );
diff --git a/resources/views/api/v4/router/server/bird2/community-filter.foil.php b/resources/views/api/v4/router/server/bird2/community-filter.foil.php
index 91642f11b..ab30faf84 100644
--- a/resources/views/api/v4/router/server/bird2/community-filter.foil.php
+++ b/resources/views/api/v4/router/server/bird2/community-filter.foil.php
@@ -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 );
     }
 
diff --git a/resources/views/api/v4/router/server/bird2/neighbors.foil.php b/resources/views/api/v4/router/server/bird2/neighbors.foil.php
index 25e4ec940..f154629cb 100644
--- a/resources/views/api/v4/router/server/bird2/neighbors.foil.php
+++ b/resources/views/api/v4/router/server/bird2/neighbors.foil.php
@@ -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 {