Index: share/man/man9/ifnet.9
===================================================================
--- share/man/man9/ifnet.9
+++ share/man/man9/ifnet.9
@@ -48,6 +48,8 @@
 .Ss "Interface Manipulation Functions"
 .Ft "struct ifnet *"
 .Fn if_alloc "u_char type"
+.Ft "struct ifnet *"
+.Fn if_alloc_domain "u_char type" "int numa_domain"
 .Ft void
 .Fn if_attach "struct ifnet *ifp"
 .Ft void
@@ -440,6 +442,14 @@
 but unlike
 .Va if_type ,
 it would not be changed by drivers.
+.It Va if_numa_domain
+.Pq Vt uint8_t
+The NUMA domain of the hardware device associated with the interface.
+This is filled in with a wildcard value unless the kernel is NUMA
+aware, the system is a NUMA system, and the device driver
+allocates the ifnet using
+.Fn if_alloc_domain
+.
 .El
 .Pp
 References to
@@ -1151,6 +1161,15 @@
 .Fa type
 specific structure in
 .Va if_l2com .
+.It Fn if_alloc_domain
+Allocate and initialize
+.Vt "struct ifnet"
+exactly as
+.Fn if_alloc
+does, but with the difference being that a driver can
+pass a
+.Fa numa_domain
+argument so that the ifnet is tagged with the appropriate NUMA domain.
 .It Fn if_attach
 Link the specified interface
 .Fa ifp
@@ -1168,7 +1187,9 @@
 The
 .Fa ifp
 must have been allocated by
-.Fn if_alloc .
+.Fn if_alloc 
+or
+.Fn if_alloc_domain .
 .It Fn if_detach
 Shut down and unlink the specified
 .Fa ifp
Index: sys/dev/cxgbe/t4_main.c
===================================================================
--- sys/dev/cxgbe/t4_main.c
+++ sys/dev/cxgbe/t4_main.c
@@ -1631,12 +1631,16 @@
 {
 	struct ifnet *ifp;
 	struct sbuf *sb;
+	int numa_domain;
 
 	vi->xact_addr_filt = -1;
 	callout_init(&vi->tick, 1);
 
 	/* Allocate an ifnet and set it up */
-	ifp = if_alloc(IFT_ETHER);
+	if (bus_get_domain(dev, &numa_domain) != 0)
+		ifp = if_alloc(IFT_ETHER);
+	else
+		ifp = if_alloc_domain(IFT_ETHER, numa_domain);
 	if (ifp == NULL) {
 		device_printf(dev, "Cannot allocate ifnet\n");
 		return (ENOMEM);
Index: sys/dev/mlx5/mlx5_en/mlx5_en_main.c
===================================================================
--- sys/dev/mlx5/mlx5_en/mlx5_en_main.c
+++ sys/dev/mlx5/mlx5_en/mlx5_en_main.c
@@ -3666,7 +3666,7 @@
 	char unit[16];
 	struct pfil_head_args pa;
 	int err;
-	int i;
+	int i, numa_domain;
 	u32 eth_proto_cap;
 
 	if (mlx5e_check_required_hca_cap(mdev)) {
@@ -3682,7 +3682,10 @@
 	    M_MLX5EN, M_WAITOK | M_ZERO);
 	mlx5e_priv_mtx_init(priv);
 
-	ifp = priv->ifp = if_alloc(IFT_ETHER);
+	if (bus_get_domain(mdev->pdev->dev.bsddev, &numa_domain) != 0)
+		ifp = priv->ifp = if_alloc(IFT_ETHER);
+	else
+		ifp = priv->ifp = if_alloc_domain(IFT_ETHER, numa_domain);
 	if (ifp == NULL) {
 		mlx5_core_err(mdev, "if_alloc() failed\n");
 		goto err_free_priv;
Index: sys/net/if.c
===================================================================
--- sys/net/if.c
+++ sys/net/if.c
@@ -39,6 +39,8 @@
 #include <sys/types.h>
 #include <sys/conf.h>
 #include <sys/malloc.h>
+#include <sys/_domainset.h>
+#include <sys/domainset.h>
 #include <sys/sbuf.h>
 #include <sys/bus.h>
 #include <sys/epoch.h>
@@ -526,13 +528,19 @@
  * registered for the passed type.
  */
 struct ifnet *
-if_alloc(u_char type)
+if_alloc_domain(u_char type, int numa_domain)
 {
 	struct ifnet *ifp;
 	u_short idx;
 	void *old;
 
-	ifp = malloc(sizeof(struct ifnet), M_IFNET, M_WAITOK|M_ZERO);
+
+	KASSERT(numa_domain <= IF_NODOM, ("numa_domain too large"));
+	if (numa_domain == IF_NODOM)
+		ifp = malloc(sizeof(struct ifnet), M_IFNET, M_WAITOK|M_ZERO);
+	else
+		ifp = malloc_domainset(sizeof(struct ifnet), M_IFNET,
+		    DOMAINSET_PREF(numa_domain), M_WAITOK|M_ZERO);
  restart:
 	IFNET_WLOCK();
 	idx = ifindex_alloc(&old);
@@ -547,6 +555,7 @@
 	ifp->if_index = idx;
 	ifp->if_type = type;
 	ifp->if_alloctype = type;
+	ifp->if_numa_domain = numa_domain;
 #ifdef VIMAGE
 	ifp->if_vnet = curvnet;
 #endif
@@ -580,6 +589,11 @@
 	return (ifp);
 }
 
+struct ifnet *
+if_alloc(u_char type)
+{
+	return (if_alloc_domain(type, IF_NODOM));
+}
 /*
  * Do the actual work of freeing a struct ifnet, and layer 2 common
  * structure.  This call is made when the last reference to an
@@ -608,7 +622,10 @@
 
 	free(ifp->if_description, M_IFDESCR);
 	free(ifp->if_hw_addr, M_IFADDR);
-	free(ifp, M_IFNET);
+	if (ifp->if_numa_domain == IF_NODOM)
+		free(ifp, M_IFNET);
+	else
+		free_domain(ifp, M_IFNET);
 }
 
 static void
Index: sys/net/if_var.h
===================================================================
--- sys/net/if_var.h
+++ sys/net/if_var.h
@@ -244,7 +244,7 @@
 	CK_STAILQ_HEAD(, ifg_list) if_groups; /* linked list of groups per if (CK_) */
 					/* protected by if_addr_lock */
 	u_char	if_alloctype;		/* if_type at time of allocation */
-
+	uint8_t	if_numa_domain;		/* NUMA domain of device */
 	/* Driver and protocol specific information that remains stable. */
 	void	*if_softc;		/* pointer to driver state */
 	void	*if_llsoftc;		/* link layer softc */
@@ -394,6 +394,7 @@
 /* for compatibility with other BSDs */
 #define	if_name(ifp)	((ifp)->if_xname)
 
+#define	IF_NODOM	255
 /*
  * Locks for address lists on the network interface.
  */
@@ -622,6 +623,7 @@
 int	if_addmulti(struct ifnet *, struct sockaddr *, struct ifmultiaddr **);
 int	if_allmulti(struct ifnet *, int);
 struct	ifnet* if_alloc(u_char);
+struct	ifnet* if_alloc_domain(u_char, int numa_domain);
 void	if_attach(struct ifnet *);
 void	if_dead(struct ifnet *);
 int	if_delmulti(struct ifnet *, struct sockaddr *);