BGP: Long-lived graceful restart enhancements (aa2ec912) · Commits · 戴 / Bird

doc/bird.sgml

+6 −3

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		@@ -1977,13 +1977,16 @@ using the following configuration parameters:
		immediately shut down. Note that this option cannot be used with
		multihop BGP. Default: disabled.

		<tag><label id="bgp-bfd">bfd <M>switch</M></tag>
		<tag><label id="bgp-bfd">bfd <M>switch</M>\|graceful</tag>
		BGP could use BFD protocol as an advisory mechanism for neighbor
		liveness and failure detection. If enabled, BIRD setups a BFD session
		for the BGP neighbor and tracks its liveness by it. This has an
		advantage of an order of magnitude lower detection times in case of
		failure. Note that BFD protocol also has to be configured, see
		<ref id="bfd" name="BFD"> section for details. Default: disabled.
		failure. When a neighbor failure is detected, the BGP session is
		restarted. Optionally, it can be configured (by <cf/graceful/ argument)
		to trigger graceful restart instead of regular restart. Note that BFD
		protocol also has to be configured, see <ref id="bfd" name="BFD">
		section for details. Default: disabled.

		<tag><label id="bgp-ttl-security">ttl security <m/switch/</tag>
		Use GTSM (<rfc id="5082"> - the generalized TTL security mechanism). GTSM

+23 −1

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		@@ -704,6 +704,12 @@ bgp_hold_timeout(timer *t)

		if (sk_rx_ready(conn->sk) > 0)
		bgp_start_timer(conn->hold_timer, 10);
		else if ((conn->state == BS_ESTABLISHED) && p->gr_ready && conn->peer_llgr_able)
		{
		BGP_TRACE(D_EVENTS, "Hold timer expired");
		bgp_handle_graceful_restart(p);
		bgp_conn_enter_idle_state(conn);
		}
		else
		bgp_error(conn, 4, 0, NULL, 0);
		}
		@@ -1048,12 +1054,28 @@ bgp_bfd_notify(struct bfd_request *req)
		if (req->down && ((ps == PS_START) \|\| (ps == PS_UP)))
		{
		BGP_TRACE(D_EVENTS, "BFD session down");

		/* Ignore if already in GR */
		if (p->gr_active && (p->cf->bfd == BGP_BFD_GRACEFUL))
		return;

		if (p->conn && (p->conn->state == BS_ESTABLISHED) &&
		p->gr_ready && (p->cf->bfd == BGP_BFD_GRACEFUL))
		{
		/* Trigger graceful restart */
		bgp_handle_graceful_restart(p);
		bgp_conn_enter_idle_state(p->conn);
		}
		else
		{
		/* Trigger session down */
		bgp_store_error(p, NULL, BE_MISC, BEM_BFD_DOWN);
		if (ps == PS_UP)
		bgp_update_startup_delay(p);
		bgp_stop(p, 0, NULL, 0);
		}
		}
		}

		static void
		bgp_update_bfd(struct bgp_proto *p, int use_bfd)

+2 −0

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		@@ -102,6 +102,8 @@ struct bgp_config {
		#define BGP_GRS_LLGR_1 2 /* Long-lived GR phase 1 (restart time) */
		#define BGP_GRS_LLGR_2 3 /* Long-lived GR phase 2 (stale time) */

		#define BGP_BFD_GRACEFUL 2 /* BFD down triggers graceful restart */


		struct bgp_conn {
		struct bgp_proto *bgp;

+1 −0

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		@@ -172,6 +172,7 @@ bgp_proto:
		\| bgp_proto TTL SECURITY bool ';' { BGP_CFG->ttl_security = $4; }
		\| bgp_proto CHECK LINK bool ';' { BGP_CFG->check_link = $4; }
		\| bgp_proto BFD bool ';' { BGP_CFG->bfd = $3; cf_check_bfd($3); }
		\| bgp_proto BFD GRACEFUL ';' { BGP_CFG->bfd = BGP_BFD_GRACEFUL; cf_check_bfd(1); }
		;

		CF_ADDTO(dynamic_attr, BGP_ORIGIN