* [PATCH iproute2-next 1/2] iplink: bridge_slave: Add support for neigh_forward_grat
2026-05-17 8:24 [PATCH iproute2-next 0/2] Add support for neigh_forward_grat Danielle Ratson
@ 2026-05-17 8:25 ` Danielle Ratson
2026-05-17 14:09 ` Nikolay Aleksandrov
2026-05-17 8:25 ` [PATCH iproute2-next 2/2] bridge: vlan: " Danielle Ratson
1 sibling, 1 reply; 5+ messages in thread
From: Danielle Ratson @ 2026-05-17 8:25 UTC (permalink / raw)
To: netdev; +Cc: dsahern, stephen, razor, petrm, idosch, Danielle Ratson
Add support for controlling gratuitous ARP and unsolicited NA
forwarding at the port level via the neigh_forward_grat option.
This allows configuring the option via:
$ ip link set dev <port> type bridge_slave neigh_forward_grat {on|off}
Or via the bridge command:
$ bridge link set dev <port> neigh_forward_grat {on|off}
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Danielle Ratson <danieller@nvidia.com>
---
bridge/link.c | 14 ++++++++++++++
ip/iplink_bridge_slave.c | 10 ++++++++++
man/man8/bridge.8 | 10 ++++++++++
man/man8/ip-link.8.in | 10 ++++++++++
4 files changed, 44 insertions(+)
diff --git a/bridge/link.c b/bridge/link.c
index 7638797d..370d7de4 100644
--- a/bridge/link.c
+++ b/bridge/link.c
@@ -174,6 +174,9 @@ static void print_protinfo(FILE *fp, struct rtattr *attr)
"neigh_vlan_suppress %s ",
rta_getattr_u8(at));
}
+ if (prtb[IFLA_BRPORT_NEIGH_FORWARD_GRAT])
+ print_on_off(PRINT_ANY, "neigh_forward_grat", "neigh_forward_grat %s ",
+ rta_getattr_u8(prtb[IFLA_BRPORT_NEIGH_FORWARD_GRAT]));
if (prtb[IFLA_BRPORT_VLAN_TUNNEL])
print_on_off(PRINT_ANY, "vlan_tunnel", "vlan_tunnel %s ",
rta_getattr_u8(prtb[IFLA_BRPORT_VLAN_TUNNEL]));
@@ -313,6 +316,7 @@ static void usage(void)
" [ mcast_max_groups MAX_GROUPS ]\n"
" [ neigh_suppress {on | off} ]\n"
" [ neigh_vlan_suppress {on | off} ]\n"
+ " [ neigh_forward_grat {on | off} ]\n"
" [ vlan_tunnel {on | off} ]\n"
" [ isolated {on | off} ]\n"
" [ locked {on | off} ]\n"
@@ -343,6 +347,7 @@ static int brlink_modify(int argc, char **argv)
int backup_port_idx = -1;
__s8 neigh_suppress = -1;
__s8 neigh_vlan_suppress = -1;
+ __s8 neigh_forward_grat = -1;
__s8 learning = -1;
__s8 learning_sync = -1;
__s8 flood = -1;
@@ -474,6 +479,12 @@ static int brlink_modify(int argc, char **argv)
*argv, &ret);
if (ret)
return ret;
+ } else if (strcmp(*argv, "neigh_forward_grat") == 0) {
+ NEXT_ARG();
+ neigh_forward_grat = parse_on_off("neigh_forward_grat",
+ *argv, &ret);
+ if (ret)
+ return ret;
} else if (strcmp(*argv, "vlan_tunnel") == 0) {
NEXT_ARG();
vlan_tunnel = parse_on_off("vlan_tunnel", *argv, &ret);
@@ -579,6 +590,9 @@ static int brlink_modify(int argc, char **argv)
if (neigh_vlan_suppress != -1)
addattr8(&req.n, sizeof(req), IFLA_BRPORT_NEIGH_VLAN_SUPPRESS,
neigh_vlan_suppress);
+ if (neigh_forward_grat != -1)
+ addattr8(&req.n, sizeof(req), IFLA_BRPORT_NEIGH_FORWARD_GRAT,
+ neigh_forward_grat);
if (vlan_tunnel != -1)
addattr8(&req.n, sizeof(req), IFLA_BRPORT_VLAN_TUNNEL,
vlan_tunnel);
diff --git a/ip/iplink_bridge_slave.c b/ip/iplink_bridge_slave.c
index 3821923b..1be02041 100644
--- a/ip/iplink_bridge_slave.c
+++ b/ip/iplink_bridge_slave.c
@@ -38,6 +38,7 @@ static void print_explain(FILE *f)
" [ group_fwd_mask MASK ]\n"
" [ neigh_suppress {on | off} ]\n"
" [ neigh_vlan_suppress {on | off} ]\n"
+ " [ neigh_forward_grat {on | off} ]\n"
" [ vlan_tunnel {on | off} ]\n"
" [ isolated {on | off} ]\n"
" [ locked {on | off} ]\n"
@@ -275,6 +276,11 @@ static void bridge_slave_print_opt(struct link_util *lu, FILE *f,
"neigh_vlan_suppress %s ",
rta_getattr_u8(tb[IFLA_BRPORT_NEIGH_VLAN_SUPPRESS]));
+ if (tb[IFLA_BRPORT_NEIGH_FORWARD_GRAT])
+ print_on_off(PRINT_ANY, "neigh_forward_grat",
+ "neigh_forward_grat %s ",
+ rta_getattr_u8(tb[IFLA_BRPORT_NEIGH_FORWARD_GRAT]));
+
if (tb[IFLA_BRPORT_GROUP_FWD_MASK]) {
char convbuf[256];
__u16 fwd_mask;
@@ -415,6 +421,10 @@ static int bridge_slave_parse_opt(struct link_util *lu, int argc, char **argv,
NEXT_ARG();
bridge_slave_parse_on_off("neigh_vlan_suppress", *argv,
n, IFLA_BRPORT_NEIGH_VLAN_SUPPRESS);
+ } else if (strcmp(*argv, "neigh_forward_grat") == 0) {
+ NEXT_ARG();
+ bridge_slave_parse_on_off("neigh_forward_grat", *argv,
+ n, IFLA_BRPORT_NEIGH_FORWARD_GRAT);
} else if (matches(*argv, "group_fwd_mask") == 0) {
__u16 mask;
diff --git a/man/man8/bridge.8 b/man/man8/bridge.8
index fe800d3f..aae6c75a 100644
--- a/man/man8/bridge.8
+++ b/man/man8/bridge.8
@@ -55,6 +55,7 @@ bridge \- show / manipulate bridge addresses and devices
.BR mcast_to_unicast " { " on " | " off " } ] [ "
.BR neigh_suppress " { " on " | " off " } ] [ "
.BR neigh_vlan_suppress " { " on " | " off " } ] [ "
+.BR neigh_forward_grat " { " on " | " off " } ] [ "
.BR vlan_tunnel " { " on " | " off " } ] [ "
.BR isolated " { " on " | " off " } ] [ "
.BR locked " { " on " | " off " } ] [ "
@@ -659,6 +660,15 @@ enabled on the port. When on, the \fBbridge link\fR option \fBneigh_suppress\fR
has no effect and the per-VLAN state is set using the \fBbridge vlan\fR option
\fBneigh_suppress\fR. By default this flag is off.
+.TP
+.BR "neigh_forward_grat on " or " neigh_forward_grat off "
+Controls whether gratuitous ARP packets and unsolicited Neighbor Advertisement
+packets are forwarded when neighbor suppression is enabled on the port.
+By default this flag is off, meaning gratuitous ARP and unsolicited NA packets
+will be suppressed when neighbor suppression is enabled. Setting this flag to
+on allows these packets to be forwarded even when neighbor suppression is
+enabled.
+
.TP
.BR "vlan_tunnel on " or " vlan_tunnel off "
Controls whether vlan to tunnel mapping is enabled on the port. By
diff --git a/man/man8/ip-link.8.in b/man/man8/ip-link.8.in
index ef45fe08..e89b2db3 100644
--- a/man/man8/ip-link.8.in
+++ b/man/man8/ip-link.8.in
@@ -2677,6 +2677,8 @@ the following additional arguments are supported:
] [
.BR neigh_vlan_suppress " { " on " | " off " }"
] [
+.BR neigh_forward_grat " { " on " | " off " }"
+] [
.BR vlan_tunnel " { " on " | " off " }"
] [
.BR isolated " { " on " | " off " }"
@@ -2791,6 +2793,14 @@ is enabled on the port. When on, the \fBbridge link\fR option
\fBneigh_suppress\fR has no effect and the per-VLAN state is set using the
\fBbridge vlan\fR option \fBneigh_suppress\fR. By default this flag is off.
+.BR neigh_forward_grat " { " on " | " off " }"
+- controls whether gratuitous ARP packets and unsolicited Neighbor
+Advertisement packets are forwarded when neighbor suppression is enabled
+on the port. By default this flag is off, meaning gratuitous ARP and
+unsolicited NA packets will be suppressed when neighbor suppression is
+enabled. Setting this flag to on allows these packets to be forwarded even
+when neighbor suppression is enabled.
+
.BR vlan_tunnel " { " on " | " off " }"
- controls whether vlan to tunnel mapping is enabled on the port. By
default this flag is off.
--
2.51.0
^ permalink raw reply related [flat|nested] 5+ messages in thread* [PATCH iproute2-next 2/2] bridge: vlan: Add support for neigh_forward_grat
2026-05-17 8:24 [PATCH iproute2-next 0/2] Add support for neigh_forward_grat Danielle Ratson
2026-05-17 8:25 ` [PATCH iproute2-next 1/2] iplink: bridge_slave: " Danielle Ratson
@ 2026-05-17 8:25 ` Danielle Ratson
2026-05-17 14:10 ` Nikolay Aleksandrov
1 sibling, 1 reply; 5+ messages in thread
From: Danielle Ratson @ 2026-05-17 8:25 UTC (permalink / raw)
To: netdev; +Cc: dsahern, stephen, razor, petrm, idosch, Danielle Ratson
Add support for controlling gratuitous ARP and unsolicited NA
forwarding at the per-VLAN level via the neigh_forward_grat option.
This allows configuring the option via:
$ bridge vlan set dev <port> vid <vlan> neigh_forward_grat {on|off}
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Danielle Ratson <danieller@nvidia.com>
---
bridge/vlan.c | 18 ++++++++++++++++++
man/man8/bridge.8 | 15 ++++++++++++++-
2 files changed, 32 insertions(+), 1 deletion(-)
diff --git a/bridge/vlan.c b/bridge/vlan.c
index 27d31ba8..ff03ac86 100644
--- a/bridge/vlan.c
+++ b/bridge/vlan.c
@@ -39,6 +39,7 @@ static void usage(void)
" [ mcast_router MULTICAST_ROUTER ]\n"
" [ mcast_max_groups MAX_GROUPS ]\n"
" [ neigh_suppress {on | off} ]\n"
+ " [ neigh_forward_grat {on | off} ]\n"
" bridge vlan { show } [ dev DEV ] [ vid VLAN_ID ]\n"
" bridge vlan { tunnelshow } [ dev DEV ] [ vid VLAN_ID ]\n"
" bridge vlan global { set } vid VLAN_ID dev DEV\n"
@@ -368,6 +369,18 @@ static int vlan_option_set(int argc, char **argv)
addattr8(&req.n, sizeof(req),
BRIDGE_VLANDB_ENTRY_NEIGH_SUPPRESS,
neigh_suppress);
+ } else if (strcmp(*argv, "neigh_forward_grat") == 0) {
+ bool neigh_forward_grat;
+ int ret;
+
+ NEXT_ARG();
+ neigh_forward_grat = parse_on_off("neigh_forward_grat",
+ *argv, &ret);
+ if (ret)
+ return ret;
+ addattr8(&req.n, sizeof(req),
+ BRIDGE_VLANDB_ENTRY_NEIGH_FORWARD_GRAT,
+ neigh_forward_grat);
} else {
if (matches(*argv, "help") == 0)
NEXT_ARG();
@@ -1012,6 +1025,11 @@ static void print_vlan_opts(struct rtattr *a, int ifindex)
print_on_off(PRINT_ANY, "neigh_suppress", "neigh_suppress %s ",
rta_getattr_u8(vattr));
}
+ if (vtb[BRIDGE_VLANDB_ENTRY_NEIGH_FORWARD_GRAT]) {
+ vattr = vtb[BRIDGE_VLANDB_ENTRY_NEIGH_FORWARD_GRAT];
+ print_on_off(PRINT_ANY, "neigh_forward_grat",
+ "neigh_forward_grat %s ", rta_getattr_u8(vattr));
+ }
print_nl();
if (show_stats)
bridge_print_vlan_stats_only(&vstats);
diff --git a/man/man8/bridge.8 b/man/man8/bridge.8
index aae6c75a..d2323521 100644
--- a/man/man8/bridge.8
+++ b/man/man8/bridge.8
@@ -241,7 +241,8 @@ bridge \- show / manipulate bridge addresses and devices
.IR MAX_GROUPS " ] [ "
.B mcast_router
.IR MULTICAST_ROUTER " ] [ "
-.BR neigh_suppress " { " on " | " off " } ]"
+.BR neigh_suppress " { " on " | " off " } ] [ "
+.BR neigh_forward_grat " { " on " | " off " } ]"
.ti -8
.BR "bridge vlan" " [ " show " | " tunnelshow " ] [ "
@@ -1486,6 +1487,18 @@ for a given VLAN on a given port. By default this flag is off.
Note that this option only takes effect when \fBbridge link\fR option
\fBneigh_vlan_suppress\fR is enabled for a given port.
+.TP
+.BR "neigh_forward_grat on " or " neigh_forward_grat off "
+Controls whether gratuitous ARP packets and unsolicited Neighbor Advertisement
+packets are forwarded when neighbor suppression is enabled for a given VLAN
+on a given port. By default this flag is off, meaning gratuitous ARP and
+unsolicited NA packets will be suppressed when neighbor suppression is enabled.
+Setting this flag to on allows these packets to be forwarded even when
+neighbor suppression is enabled.
+
+Note that this option only takes effect when \fBbridge link\fR option
+\fBneigh_vlan_suppress\fR is enabled for a given port.
+
.SS bridge vlan show - list vlan configuration.
This command displays the current VLAN filter table.
--
2.51.0
^ permalink raw reply related [flat|nested] 5+ messages in thread