Merge pull request #17241 from opensourcerouting/fix/backport_d46511d4456ccaccfdac34b456c1c225a29609c8_9.1

bgpd: compare aigp after local route check in bgp_path_info_cmp()

2 files changed, 30 insertions, 33 deletions

diff --git a/bgpd/bgp_route.c b/bgpd/bgp_route.c
index 6dc19a6256..4f1afac5d5 100644
--- a/bgpd/bgp_route.c
+++ b/bgpd/bgp_route.c
@@ -953,7 +953,32 @@ int bgp_path_info_cmp(struct bgp *bgp, struct bgp_path_info *new,
 		}
 	}
 
-	/* Tie-breaker - AIGP (Metric TLV) attribute */
+	/* 3. Local route check. We prefer:
+	 *  - BGP_ROUTE_STATIC
+	 *  - BGP_ROUTE_AGGREGATE
+	 *  - BGP_ROUTE_REDISTRIBUTE
+	 */
+	new_origin = !(new->sub_type == BGP_ROUTE_NORMAL || new->sub_type == BGP_ROUTE_IMPORTED);
+	exist_origin = !(exist->sub_type == BGP_ROUTE_NORMAL ||
+			 exist->sub_type == BGP_ROUTE_IMPORTED);
+
+	if (new_origin && !exist_origin) {
+		*reason = bgp_path_selection_local_route;
+		if (debug)
+			zlog_debug("%s: %s wins over %s due to preferred BGP_ROUTE type", pfx_buf,
+				   new_buf, exist_buf);
+		return 1;
+	}
+
+	if (!new_origin && exist_origin) {
+		*reason = bgp_path_selection_local_route;
+		if (debug)
+			zlog_debug("%s: %s loses to %s due to preferred BGP_ROUTE type", pfx_buf,
+				   new_buf, exist_buf);
+		return 0;
+	}
+
+	/* 3.5. Tie-breaker - AIGP (Metric TLV) attribute */
 	if (CHECK_FLAG(newattr->flag, ATTR_FLAG_BIT(BGP_ATTR_AIGP)) &&
 	    CHECK_FLAG(existattr->flag, ATTR_FLAG_BIT(BGP_ATTR_AIGP)) &&
 	    CHECK_FLAG(bgp->flags, BGP_FLAG_COMPARE_AIGP)) {
@@ -983,34 +1008,6 @@ int bgp_path_info_cmp(struct bgp *bgp, struct bgp_path_info *new,
 		}
 	}
 
-	/* 3. Local route check. We prefer:
-	 *  - BGP_ROUTE_STATIC
-	 *  - BGP_ROUTE_AGGREGATE
-	 *  - BGP_ROUTE_REDISTRIBUTE
-	 */
-	new_origin = !(new->sub_type == BGP_ROUTE_NORMAL ||
-		       new->sub_type == BGP_ROUTE_IMPORTED);
-	exist_origin = !(exist->sub_type == BGP_ROUTE_NORMAL ||
-			 exist->sub_type == BGP_ROUTE_IMPORTED);
-
-	if (new_origin && !exist_origin) {
-		*reason = bgp_path_selection_local_route;
-		if (debug)
-			zlog_debug(
-				"%s: %s wins over %s due to preferred BGP_ROUTE type",
-				pfx_buf, new_buf, exist_buf);
-		return 1;
-	}
-
-	if (!new_origin && exist_origin) {
-		*reason = bgp_path_selection_local_route;
-		if (debug)
-			zlog_debug(
-				"%s: %s loses to %s due to preferred BGP_ROUTE type",
-				pfx_buf, new_buf, exist_buf);
-		return 0;
-	}
-
 	/* Here if these are imported routes then get ultimate pi for
 	 * path compare.
 	 */
diff --git a/doc/user/bgp.rst b/doc/user/bgp.rst
index 35004db2fb..46653595f4 100644
--- a/doc/user/bgp.rst
+++ b/doc/user/bgp.rst
@@ -157,16 +157,16 @@ bottom until one of the factors can be used.
 
    Prefer higher local preference routes to lower.
 
+3. **Local route check**
+
+   Prefer local routes (statics, aggregates, redistributed) to received routes.
+
    If ``bgp bestpath aigp`` is enabled, and both paths that are compared have
    AIGP attribute, BGP uses AIGP tie-breaking unless both of the paths have the
    AIGP metric attribute. This means that the AIGP attribute is not evaluated
    during the best path selection process between two paths when one path does
    not have the AIGP attribute.
 
-3. **Local route check**
-
-   Prefer local routes (statics, aggregates, redistributed) to received routes.
-
 4. **AS path length check**
 
    Prefer shortest hop-count AS_PATHs.