diff --git a/src/libnm-platform/nm-platform.c b/src/libnm-platform/nm-platform.c
index 089d0d42c1..7c9594e2ea 100644
--- a/src/libnm-platform/nm-platform.c
+++ b/src/libnm-platform/nm-platform.c
@@ -6524,6 +6524,7 @@ nm_platform_ip4_route_to_string(const NMPlatformIP4Route *route, char *buf, gsiz
         "%s"                                   /* initcwnd */
         "%s"                                   /* initrwnd */
         "%s"                                   /* mtu */
+        "%s"                                   /* is_external */
         "",
         nm_net_aux_rtnl_rtntype_n2a_maybe_buf(nm_platform_route_type_uncoerce(route->type_coerced),
                                               str_type),
@@ -6579,7 +6580,8 @@ nm_platform_ip4_route_to_string(const NMPlatformIP4Route *route, char *buf, gsiz
                                                        " mtu %s%" G_GUINT32_FORMAT,
                                                        route->lock_mtu ? "lock " : "",
                                                        route->mtu)
-                                      : "");
+                                      : "",
+        route->is_external ? " (E)" : "");
     return buf;
 }
 
@@ -6649,6 +6651,7 @@ nm_platform_ip6_route_to_string(const NMPlatformIP6Route *route, char *buf, gsiz
         "%s"                                   /* initrwnd */
         "%s"                                   /* mtu */
         "%s"                                   /* pref */
+        "%s"                                   /* is_external */
         "",
         nm_net_aux_rtnl_rtntype_n2a_maybe_buf(nm_platform_route_type_uncoerce(route->type_coerced),
                                               str_type),
@@ -6708,7 +6711,8 @@ nm_platform_ip6_route_to_string(const NMPlatformIP6Route *route, char *buf, gsiz
             str_pref,
             " pref %s",
             nm_icmpv6_router_pref_to_string(route->rt_pref, str_pref2, sizeof(str_pref2)))
-                       : "");
+                       : "",
+        route->is_external ? " (E)" : "");
 
     return buf;
 }
@@ -8005,7 +8009,8 @@ nm_platform_ip4_route_hash_update(const NMPlatformIP4Route *obj,
                                                   obj->lock_cwnd,
                                                   obj->lock_initcwnd,
                                                   obj->lock_initrwnd,
-                                                  obj->lock_mtu));
+                                                  obj->lock_mtu,
+                                                  obj->is_external));
         break;
     }
 }
@@ -8095,6 +8100,8 @@ nm_platform_ip4_route_cmp(const NMPlatformIP4Route *a,
         NM_CMP_FIELD(a, b, initcwnd);
         NM_CMP_FIELD(a, b, initrwnd);
         NM_CMP_FIELD(a, b, mtu);
+        if (cmp_type == NM_PLATFORM_IP_ROUTE_CMP_TYPE_FULL)
+            NM_CMP_FIELD_UNSAFE(a, b, is_external);
         break;
     }
     return 0;
@@ -8186,7 +8193,8 @@ nm_platform_ip6_route_hash_update(const NMPlatformIP6Route *obj,
                                                   obj->lock_cwnd,
                                                   obj->lock_initcwnd,
                                                   obj->lock_initrwnd,
-                                                  obj->lock_mtu),
+                                                  obj->lock_mtu,
+                                                  obj->is_external),
                             obj->window,
                             obj->cwnd,
                             obj->initcwnd,
@@ -8269,6 +8277,8 @@ nm_platform_ip6_route_cmp(const NMPlatformIP6Route *a,
             NM_CMP_DIRECT(_route_pref_normalize(a->rt_pref), _route_pref_normalize(b->rt_pref));
         else
             NM_CMP_FIELD(a, b, rt_pref);
+        if (cmp_type == NM_PLATFORM_IP_ROUTE_CMP_TYPE_FULL)
+            NM_CMP_FIELD_UNSAFE(a, b, is_external);
         break;
     }
     return 0;
diff --git a/src/libnm-platform/nm-platform.h b/src/libnm-platform/nm-platform.h
index 6fe723cba4..5b7a73e887 100644
--- a/src/libnm-platform/nm-platform.h
+++ b/src/libnm-platform/nm-platform.h
@@ -462,6 +462,14 @@ typedef union {
      * the "table_coerced" field is ignored (unlike for the metric). */            \
     bool table_any : 1;                                                                   \
                                                                                           \
+    /* This route is tracked as external route, that is not a route that NetworkManager
+     * actively wants to add, but a route that was added externally. In some cases, such
+     * a route should be ignored.
+     *
+     * Note that unlike most other fields here, this flag only exists inside NetworkManager
+     * and is not reflected on netlink. */   \
+    bool is_external : 1;                                                                 \
+                                                                                          \
     /* rtnh_flags
      *
      * Routes with rtm_flags RTM_F_CLONED are hidden by platform and