bgpd: implement "next-hop-self all"
As specified in:
http://www.cisco.com/c/en/us/td/docs/ios-xml/ios/iproute_bgp/command/irg-cr-book/bgp-m1.html#wp4972925610
This allows overriding next-hop for ibgp learned routes on an
RR for reflected routes.
Especially useful for using iBGP in DMVPN setups. See:
http://blog.ipspace.net/2014/04/changes-in-ibgp-next-hop-processing.html
Signed-off-by: Timo Teräs <timo.teras@iki.fi>
diff --git a/bgpd/bgp_route.c b/bgpd/bgp_route.c
index f421ca5..232a6a1 100644
--- a/bgpd/bgp_route.c
+++ b/bgpd/bgp_route.c
@@ -976,7 +976,8 @@
}
/* next-hop-set */
- if (transparent || reflect
+ if (transparent
+ || (reflect && ! CHECK_FLAG (peer->af_flags[afi][safi], PEER_FLAG_NEXTHOP_SELF_ALL))
|| (CHECK_FLAG (peer->af_flags[afi][safi], PEER_FLAG_NEXTHOP_UNCHANGED)
&& ((p->family == AF_INET && attr->nexthop.s_addr)
#ifdef HAVE_IPV6
diff --git a/bgpd/bgp_vty.c b/bgpd/bgp_vty.c
index 3c6973b..a818fe7 100644
--- a/bgpd/bgp_vty.c
+++ b/bgpd/bgp_vty.c
@@ -2093,25 +2093,41 @@
/* neighbor next-hop-self. */
DEFUN (neighbor_nexthop_self,
neighbor_nexthop_self_cmd,
- NEIGHBOR_CMD2 "next-hop-self",
+ NEIGHBOR_CMD2 "next-hop-self {all}",
NEIGHBOR_STR
NEIGHBOR_ADDR_STR2
- "Disable the next hop calculation for this neighbor\n")
+ "Disable the next hop calculation for this neighbor\n"
+ "Apply also to ibgp-learned routes when acting as a route reflector\n")
{
- return peer_af_flag_set_vty (vty, argv[0], bgp_node_afi (vty),
- bgp_node_safi (vty), PEER_FLAG_NEXTHOP_SELF);
+ u_int32_t flags = PEER_FLAG_NEXTHOP_SELF, unset = 0;
+ int rc;
+
+ /* Check if "all" is specified */
+ if (argv[1] != NULL)
+ flags |= PEER_FLAG_NEXTHOP_SELF_ALL;
+ else
+ unset |= PEER_FLAG_NEXTHOP_SELF_ALL;
+
+ rc = peer_af_flag_set_vty (vty, argv[0], bgp_node_afi (vty),
+ bgp_node_safi (vty), flags);
+ if ( rc == CMD_SUCCESS && unset )
+ rc = peer_af_flag_unset_vty (vty, argv[0], bgp_node_afi (vty),
+ bgp_node_safi (vty), unset);
+ return rc;
}
DEFUN (no_neighbor_nexthop_self,
no_neighbor_nexthop_self_cmd,
- NO_NEIGHBOR_CMD2 "next-hop-self",
+ NO_NEIGHBOR_CMD2 "next-hop-self {all}",
NO_STR
NEIGHBOR_STR
NEIGHBOR_ADDR_STR2
- "Disable the next hop calculation for this neighbor\n")
+ "Disable the next hop calculation for this neighbor\n"
+ "Apply also to ibgp-learned routes when acting as a route reflector\n")
{
return peer_af_flag_unset_vty (vty, argv[0], bgp_node_afi (vty),
- bgp_node_safi (vty), PEER_FLAG_NEXTHOP_SELF);
+ bgp_node_safi (vty),
+ PEER_FLAG_NEXTHOP_SELF|PEER_FLAG_NEXTHOP_SELF_ALL);
}
/* neighbor remove-private-AS. */
diff --git a/bgpd/bgpd.c b/bgpd/bgpd.c
index 19b96fa..4d374cc 100644
--- a/bgpd/bgpd.c
+++ b/bgpd/bgpd.c
@@ -2355,6 +2355,7 @@
{ PEER_FLAG_ORF_PREFIX_SM, 1, peer_change_reset },
{ PEER_FLAG_ORF_PREFIX_RM, 1, peer_change_reset },
{ PEER_FLAG_NEXTHOP_LOCAL_UNCHANGED, 0, peer_change_reset_out },
+ { PEER_FLAG_NEXTHOP_SELF_ALL, 1, peer_change_reset_out },
{ 0, 0, 0 }
};
@@ -4990,7 +4991,9 @@
/* Nexthop self. */
if (peer_af_flag_check (peer, afi, safi, PEER_FLAG_NEXTHOP_SELF)
&& ! peer->af_group[afi][safi])
- vty_out (vty, " neighbor %s next-hop-self%s", addr, VTY_NEWLINE);
+ vty_out (vty, " neighbor %s next-hop-self%s%s", addr,
+ peer_af_flag_check (peer, afi, safi, PEER_FLAG_NEXTHOP_SELF_ALL) ?
+ " all" : "", VTY_NEWLINE);
/* Remove private AS. */
if (peer_af_flag_check (peer, afi, safi, PEER_FLAG_REMOVE_PRIVATE_AS)
diff --git a/bgpd/bgpd.h b/bgpd/bgpd.h
index a1b1273..eae803d 100644
--- a/bgpd/bgpd.h
+++ b/bgpd/bgpd.h
@@ -412,6 +412,7 @@
#define PEER_FLAG_MAX_PREFIX (1 << 14) /* maximum prefix */
#define PEER_FLAG_MAX_PREFIX_WARNING (1 << 15) /* maximum prefix warning-only */
#define PEER_FLAG_NEXTHOP_LOCAL_UNCHANGED (1 << 16) /* leave link-local nexthop unchanged */
+#define PEER_FLAG_NEXTHOP_SELF_ALL (1 << 17) /* next-hop-self all */
/* MD5 password */
char *password;
diff --git a/doc/bgpd.texi b/doc/bgpd.texi
index cb9789b..de70970 100644
--- a/doc/bgpd.texi
+++ b/doc/bgpd.texi
@@ -299,10 +299,12 @@
use should be avoided.
@end deffn
-@deffn {BGP} {neighbor @var{peer} next-hop-self} {}
-@deffnx {BGP} {no neighbor @var{peer} next-hop-self} {}
+@deffn {BGP} {neighbor @var{peer} next-hop-self [all]} {}
+@deffnx {BGP} {no neighbor @var{peer} next-hop-self [all]} {}
This command specifies an announced route's nexthop as being equivalent
-to the address of the bgp router.
+to the address of the bgp router if it is learned via eBGP.
+If the optional keyword @code{all} is specified the modifiation is done
+also for routes learned via iBGP.
@end deffn
@deffn {BGP} {neighbor @var{peer} update-source @var{<ifname|address>}} {}