bgpd, tests: don't send local nexthop from rr client

AS 65000 | AS 65001 | RR | | | R1 --- | --- R2 | When r1 peer is an iBGP route reflector client of rr and r2 peer is a eBGP neighbor of rr, and all three routers shares the same network, r2 receives announcements coming from r1 with a IPv6 link-local nexthop from rr. This is incorrect as r2 should send traffic to r1 without involving rr. Do not send an IPv6 link-local nexthop if the originating peer is a route-reflector client. Link: FRRouting#16219 (comment) Link: FRRouting#17037 (comment) Signed-off-by: Louis Scalbert <[email protected]>
louis-6wind · Oct 11, 2024 · d494470 · d494470
1 parent e40dd02
commit d494470
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Showing 3 changed files with 13 additions and 84 deletions.
diff --git a/bgpd/bgp_route.c b/bgpd/bgp_route.c
@@ -2472,6 +2472,7 @@ bool subgroup_announce_check(struct bgp_dest *dest, struct bgp_path_info *pi,
 			if (IN6_IS_ADDR_LINKLOCAL(&attr->mp_nexthop_local))
 				global_and_ll = true;
 		} else if (!ibgp_to_ibgp && !transparent &&
+			   !CHECK_FLAG(from->af_flags[afi][safi], PEER_FLAG_REFLECTOR_CLIENT) &&
 			   IN6_IS_ADDR_LINKLOCAL(&peer->nexthop.v6_local) && peer->shared_network &&
 			   (from == bgp->peer_self || peer->sort == BGP_PEER_EBGP))
 			global_and_ll = true;

diff --git a/tests/topotests/bgp_nexthop_ipv6/r4/show_bgp_ipv6_step2.json b/tests/topotests/bgp_nexthop_ipv6/r4/show_bgp_ipv6_step2.json
@@ -9,13 +9,7 @@
             "ip": "fd00:0:2::1",
             "hostname": "rr",
             "afi": "ipv6",
-            "scope": "global"
-          },
-          {
-            "ip": "link-local:rr:eth-sw",
-            "hostname": "rr",
-            "afi": "ipv6",
-            "scope": "link-local",
+            "scope": "global",
             "used": true
           }
         ]
@@ -28,13 +22,7 @@
             "ip": "fd00:0:2::2",
             "hostname": "rr",
             "afi": "ipv6",
-            "scope": "global"
-          },
-          {
-            "ip": "link-local:rr:eth-sw",
-            "hostname": "rr",
-            "afi": "ipv6",
-            "scope": "link-local",
+            "scope": "global",
             "used": true
           }
         ]
@@ -47,13 +35,7 @@
             "ip": "fd00:0:2::3",
             "hostname": "rr",
             "afi": "ipv6",
-            "scope": "global"
-          },
-          {
-            "ip": "link-local:rr:eth-sw",
-            "hostname": "rr",
-            "afi": "ipv6",
-            "scope": "link-local",
+            "scope": "global",
             "used": true
           }
         ]
@@ -117,13 +99,7 @@
             "ip": "fd00:0:2::1",
             "hostname": "rr",
             "afi": "ipv6",
-            "scope": "global"
-          },
-          {
-            "ip": "link-local:rr:eth-sw",
-            "hostname": "rr",
-            "afi": "ipv6",
-            "scope": "link-local",
+            "scope": "global",
             "used": true
           }
         ]
@@ -136,13 +112,7 @@
             "ip": "fd00:0:2::2",
             "hostname": "rr",
             "afi": "ipv6",
-            "scope": "global"
-          },
-          {
-            "ip": "link-local:rr:eth-sw",
-            "hostname": "rr",
-            "afi": "ipv6",
-            "scope": "link-local",
+            "scope": "global",
             "used": true
           }
         ]
@@ -155,13 +125,7 @@
             "ip": "fd00:0:2::3",
             "hostname": "rr",
             "afi": "ipv6",
-            "scope": "global"
-          },
-          {
-            "ip": "link-local:rr:eth-sw",
-            "hostname": "rr",
-            "afi": "ipv6",
-            "scope": "link-local",
+            "scope": "global",
             "used": true
           }
         ]

diff --git a/tests/topotests/bgp_nexthop_ipv6/r5/show_bgp_ipv6_step2.json b/tests/topotests/bgp_nexthop_ipv6/r5/show_bgp_ipv6_step2.json
@@ -9,13 +9,7 @@
             "ip": "fd00:0:3::9",
             "hostname": "rr",
             "afi": "ipv6",
-            "scope": "global"
-          },
-          {
-            "ip": "link-local:rr:eth-r5",
-            "hostname": "rr",
-            "afi": "ipv6",
-            "scope": "link-local",
+            "scope": "global",
             "used": true
           }
         ]
@@ -28,13 +22,7 @@
             "ip": "fd00:0:3::9",
             "hostname": "rr",
             "afi": "ipv6",
-            "scope": "global"
-          },
-          {
-            "ip": "link-local:rr:eth-r5",
-            "hostname": "rr",
-            "afi": "ipv6",
-            "scope": "link-local",
+            "scope": "global",
             "used": true
           }
         ]
@@ -47,13 +35,7 @@
             "ip": "fd00:0:3::9",
             "hostname": "rr",
             "afi": "ipv6",
-            "scope": "global"
-          },
-          {
-            "ip": "link-local:rr:eth-r5",
-            "hostname": "rr",
-            "afi": "ipv6",
-            "scope": "link-local",
+            "scope": "global",
             "used": true
           }
         ]
@@ -117,13 +99,7 @@
             "ip": "fd00:0:3::9",
             "hostname": "rr",
             "afi": "ipv6",
-            "scope": "global"
-          },
-          {
-            "ip": "link-local:rr:eth-r5",
-            "hostname": "rr",
-            "afi": "ipv6",
-            "scope": "link-local",
+            "scope": "global",
             "used": true
           }
         ]
@@ -136,13 +112,7 @@
             "ip": "fd00:0:3::9",
             "hostname": "rr",
             "afi": "ipv6",
-            "scope": "global"
-          },
-          {
-            "ip": "link-local:rr:eth-r5",
-            "hostname": "rr",
-            "afi": "ipv6",
-            "scope": "link-local",
+            "scope": "global",
             "used": true
           }
         ]
@@ -155,13 +125,7 @@
             "ip": "fd00:0:3::9",
             "hostname": "rr",
             "afi": "ipv6",
-            "scope": "global"
-          },
-          {
-            "ip": "link-local:rr:eth-r5",
-            "hostname": "rr",
-            "afi": "ipv6",
-            "scope": "link-local",
+            "scope": "global",
             "used": true
           }
         ]