diff --git a/proto/bgp/attrs.c b/proto/bgp/attrs.c
index 4346cd5d..85646647 100644
--- a/proto/bgp/attrs.c
+++ b/proto/bgp/attrs.c
@@ -89,7 +89,7 @@ bgp_set_attr(ea_list **attrs, struct linpool *pool, uint code, uint flags, uintp
       attrs,
       pool,
       EA_CODE(PROTOCOL_BGP, code),
-      flags & ~BAF_EXT_LEN,
+      bgp_attr_table[code].flags | (flags & BAF_PARTIAL),
       bgp_attr_table[code].type,
       val
   );
@@ -1158,13 +1158,6 @@ bgp_attr_name(uint code)
   return (code < ARRAY_SIZE(bgp_attr_table)) ? bgp_attr_table[code].name : NULL;
 }
 
-void bgp_fix_attr_flags(ea_list *attrs)
-{
-  for (u8 i = 0; i < attrs->count; i++)
-  {
-    attrs->attrs[i].flags = bgp_attr_table[EA_ID(attrs->attrs[i].id)].flags;
-  }
-}
 
 /*
  *	Attribute export
@@ -1182,7 +1175,8 @@ bgp_export_attr(struct bgp_export_state *s, eattr *a, ea_list *to)
   {
     const struct bgp_attr_desc *desc = &bgp_attr_table[code];
 
-    /* The flags might have been zero if the attr was added by filters */
+    /* The flags should be correct, we reset them just to be sure */
+    ASSERT(!((a->flags ^ desc->flags) & (BAF_OPTIONAL | BAF_TRANSITIVE)));
     a->flags = (a->flags & BAF_PARTIAL) | desc->flags;
 
     /* Set partial bit if new opt-trans attribute is attached to non-local route */
diff --git a/proto/bgp/config.Y b/proto/bgp/config.Y
index 1173ff06..4ce06488 100644
--- a/proto/bgp/config.Y
+++ b/proto/bgp/config.Y
@@ -349,33 +349,33 @@ bgp_proto_channel: bgp_channel_start bgp_channel_opt_list bgp_channel_end;
 
 
 dynamic_attr: BGP_ORIGIN
-	{ $$ = f_new_dynamic_attr(EAF_TYPE_INT, T_ENUM_BGP_ORIGIN, EA_CODE(PROTOCOL_BGP, BA_ORIGIN)); } ;
+	{ $$ = f_new_dynamic_attr(EAF_TYPE_INT, T_ENUM_BGP_ORIGIN, EA_CODE(PROTOCOL_BGP, BA_ORIGIN));	$$.flags = BAF_TRANSITIVE; } ;
 dynamic_attr: BGP_PATH
-	{ $$ = f_new_dynamic_attr(EAF_TYPE_AS_PATH, T_PATH, EA_CODE(PROTOCOL_BGP, BA_AS_PATH)); } ;
+	{ $$ = f_new_dynamic_attr(EAF_TYPE_AS_PATH, T_PATH, EA_CODE(PROTOCOL_BGP, BA_AS_PATH));		$$.flags = BAF_TRANSITIVE; } ;
 dynamic_attr: BGP_NEXT_HOP
-	{ $$ = f_new_dynamic_attr(EAF_TYPE_IP_ADDRESS, T_IP, EA_CODE(PROTOCOL_BGP, BA_NEXT_HOP)); } ;
+	{ $$ = f_new_dynamic_attr(EAF_TYPE_IP_ADDRESS, T_IP, EA_CODE(PROTOCOL_BGP, BA_NEXT_HOP));	$$.flags = BAF_TRANSITIVE; } ;
 dynamic_attr: BGP_MED
-	{ $$ = f_new_dynamic_attr(EAF_TYPE_INT, T_INT, EA_CODE(PROTOCOL_BGP, BA_MULTI_EXIT_DISC)); } ;
+	{ $$ = f_new_dynamic_attr(EAF_TYPE_INT, T_INT, EA_CODE(PROTOCOL_BGP, BA_MULTI_EXIT_DISC));	$$.flags = BAF_OPTIONAL; } ;
 dynamic_attr: BGP_LOCAL_PREF
-	{ $$ = f_new_dynamic_attr(EAF_TYPE_INT, T_INT, EA_CODE(PROTOCOL_BGP, BA_LOCAL_PREF)); } ;
+	{ $$ = f_new_dynamic_attr(EAF_TYPE_INT, T_INT, EA_CODE(PROTOCOL_BGP, BA_LOCAL_PREF));		$$.flags = BAF_TRANSITIVE; } ;
 dynamic_attr: BGP_ATOMIC_AGGR
-	{ $$ = f_new_dynamic_attr(EAF_TYPE_OPAQUE, T_ENUM_EMPTY, EA_CODE(PROTOCOL_BGP, BA_ATOMIC_AGGR)); } ;
+	{ $$ = f_new_dynamic_attr(EAF_TYPE_OPAQUE, T_ENUM_EMPTY, EA_CODE(PROTOCOL_BGP, BA_ATOMIC_AGGR)); $$.flags = BAF_TRANSITIVE; } ;
 dynamic_attr: BGP_AGGREGATOR
-	{ $$ = f_new_dynamic_attr(EAF_TYPE_OPAQUE, T_ENUM_EMPTY, EA_CODE(PROTOCOL_BGP, BA_AGGREGATOR)); } ;
+	{ $$ = f_new_dynamic_attr(EAF_TYPE_OPAQUE, T_ENUM_EMPTY, EA_CODE(PROTOCOL_BGP, BA_AGGREGATOR));	$$.flags = BAF_OPTIONAL | BAF_TRANSITIVE; } ;
 dynamic_attr: BGP_COMMUNITY
-	{ $$ = f_new_dynamic_attr(EAF_TYPE_INT_SET, T_CLIST, EA_CODE(PROTOCOL_BGP, BA_COMMUNITY)); } ;
+	{ $$ = f_new_dynamic_attr(EAF_TYPE_INT_SET, T_CLIST, EA_CODE(PROTOCOL_BGP, BA_COMMUNITY));	$$.flags = BAF_OPTIONAL | BAF_TRANSITIVE; } ;
 dynamic_attr: BGP_ORIGINATOR_ID
-	{ $$ = f_new_dynamic_attr(EAF_TYPE_ROUTER_ID, T_QUAD, EA_CODE(PROTOCOL_BGP, BA_ORIGINATOR_ID)); } ;
+	{ $$ = f_new_dynamic_attr(EAF_TYPE_ROUTER_ID, T_QUAD, EA_CODE(PROTOCOL_BGP, BA_ORIGINATOR_ID));	$$.flags = BAF_OPTIONAL; } ;
 dynamic_attr: BGP_CLUSTER_LIST
-	{ $$ = f_new_dynamic_attr(EAF_TYPE_INT_SET, T_CLIST, EA_CODE(PROTOCOL_BGP, BA_CLUSTER_LIST)); } ;
+	{ $$ = f_new_dynamic_attr(EAF_TYPE_INT_SET, T_CLIST, EA_CODE(PROTOCOL_BGP, BA_CLUSTER_LIST));	$$.flags = BAF_OPTIONAL; } ;
 dynamic_attr: BGP_EXT_COMMUNITY
-	{ $$ = f_new_dynamic_attr(EAF_TYPE_EC_SET, T_ECLIST, EA_CODE(PROTOCOL_BGP, BA_EXT_COMMUNITY)); } ;
+	{ $$ = f_new_dynamic_attr(EAF_TYPE_EC_SET, T_ECLIST, EA_CODE(PROTOCOL_BGP, BA_EXT_COMMUNITY));	$$.flags = BAF_OPTIONAL | BAF_TRANSITIVE; } ;
 dynamic_attr: BGP_AIGP
-	{ $$ = f_new_dynamic_attr(EAF_TYPE_OPAQUE, T_ENUM_EMPTY, EA_CODE(PROTOCOL_BGP, BA_AIGP)); } ;
+	{ $$ = f_new_dynamic_attr(EAF_TYPE_OPAQUE, T_ENUM_EMPTY, EA_CODE(PROTOCOL_BGP, BA_AIGP));	$$.flags = BAF_OPTIONAL; } ;
 dynamic_attr: BGP_LARGE_COMMUNITY
-	{ $$ = f_new_dynamic_attr(EAF_TYPE_LC_SET, T_LCLIST, EA_CODE(PROTOCOL_BGP, BA_LARGE_COMMUNITY)); } ;
+	{ $$ = f_new_dynamic_attr(EAF_TYPE_LC_SET, T_LCLIST, EA_CODE(PROTOCOL_BGP, BA_LARGE_COMMUNITY)); $$.flags = BAF_OPTIONAL | BAF_TRANSITIVE; } ;
 dynamic_attr: BGP_OTC
-	{ $$ = f_new_dynamic_attr(EAF_TYPE_INT, T_INT, EA_CODE(PROTOCOL_BGP, BA_ONLY_TO_CUSTOMER)); } ;
+	{ $$ = f_new_dynamic_attr(EAF_TYPE_INT, T_INT, EA_CODE(PROTOCOL_BGP, BA_ONLY_TO_CUSTOMER));	$$.flags = BAF_OPTIONAL | BAF_TRANSITIVE; } ;
 
 custom_attr: ATTRIBUTE BGP expr type symbol ';' {
   if ($3 > 255 || $3 < 1)