diff --git a/sys/compat/linux/linux_netlink.c b/sys/compat/linux/linux_netlink.c
index 0e8188d4cdf6..775a36994d2d 100644
--- a/sys/compat/linux/linux_netlink.c
+++ b/sys/compat/linux/linux_netlink.c
@@ -312,7 +312,7 @@ rtnl_if_flags_to_linux(unsigned int if_flags)
 		case IFF_ALLMULTI:
 			result |= flag;
 			break;
-		case IFF_KNOWSEPOCH:
+		case IFF_NEEDSEPOCH:
 		case IFF_DRV_OACTIVE:
 		case IFF_SIMPLEX:
 		case IFF_LINK0:
diff --git a/sys/dev/ena/ena.c b/sys/dev/ena/ena.c
index 72846a8bed51..a4762ce9ebb1 100644
--- a/sys/dev/ena/ena.c
+++ b/sys/dev/ena/ena.c
@@ -2393,8 +2393,7 @@ ena_setup_ifnet(device_t pdev, struct ena_adapter *adapter,
 	if_setdev(ifp, pdev);
 	if_setsoftc(ifp, adapter);
 
-	if_setflags(ifp,
-	    IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST | IFF_KNOWSEPOCH);
+	if_setflags(ifp, IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST);
 	if_setinitfn(ifp, ena_init);
 	if_settransmitfn(ifp, ena_mq_start);
 	if_setqflushfn(ifp, ena_qflush);
diff --git a/sys/dev/mlx5/mlx5_en/mlx5_en_main.c b/sys/dev/mlx5/mlx5_en/mlx5_en_main.c
index 84adef8398bb..ab0cf49c2e8a 100644
--- a/sys/dev/mlx5/mlx5_en/mlx5_en_main.c
+++ b/sys/dev/mlx5/mlx5_en/mlx5_en_main.c
@@ -4526,8 +4526,7 @@ mlx5e_create_ifp(struct mlx5_core_dev *mdev)
 	if_initname(ifp, "mce", device_get_unit(mdev->pdev->dev.bsddev));
 	if_setmtu(ifp, ETHERMTU);
 	if_setinitfn(ifp, mlx5e_open);
-	if_setflags(ifp, IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST |
-	    IFF_KNOWSEPOCH);
+	if_setflags(ifp, IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST);
 	if_setioctlfn(ifp, mlx5e_ioctl);
 	if_settransmitfn(ifp, mlx5e_xmit);
 	if_setqflushfn(ifp, if_qflush);
diff --git a/sys/dev/oce/oce_if.c b/sys/dev/oce/oce_if.c
index cc8cfc3eaa8c..5d250fcac0bd 100644
--- a/sys/dev/oce/oce_if.c
+++ b/sys/dev/oce/oce_if.c
@@ -2111,7 +2111,7 @@ oce_attach_ifp(POCE_SOFTC sc)
 	ifmedia_add(&sc->media, IFM_ETHER | IFM_AUTO, 0, NULL);
 	ifmedia_set(&sc->media, IFM_ETHER | IFM_AUTO);
 
-	if_setflags(sc->ifp, IFF_BROADCAST | IFF_MULTICAST | IFF_KNOWSEPOCH);
+	if_setflags(sc->ifp, IFF_BROADCAST | IFF_MULTICAST);
 	if_setioctlfn(sc->ifp, oce_ioctl);
 	if_setstartfn(sc->ifp, oce_start);
 	if_setinitfn(sc->ifp, oce_init);
diff --git a/sys/dev/virtio/network/if_vtnet.c b/sys/dev/virtio/network/if_vtnet.c
index 41eaa6a56086..9ef667e97a54 100644
--- a/sys/dev/virtio/network/if_vtnet.c
+++ b/sys/dev/virtio/network/if_vtnet.c
@@ -1103,8 +1103,7 @@ vtnet_setup_interface(struct vtnet_softc *sc)
 	dev = sc->vtnet_dev;
 	ifp = sc->vtnet_ifp;
 
-	if_setflags(ifp, IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST |
-	    IFF_KNOWSEPOCH);
+	if_setflags(ifp, IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST);
 	if_setbaudrate(ifp, IF_Gbps(10));
 	if_setinitfn(ifp, vtnet_init);
 	if_setioctlfn(ifp, vtnet_ioctl);
diff --git a/sys/net/if.h b/sys/net/if.h
index 888e7d5d7320..da3d25f2b226 100644
--- a/sys/net/if.h
+++ b/sys/net/if.h
@@ -144,7 +144,7 @@ struct if_data {
 #define	IFF_DEBUG	0x4		/* (n) turn on debugging */
 #define	IFF_LOOPBACK	0x8		/* (i) is a loopback net */
 #define	IFF_POINTOPOINT	0x10		/* (i) is a point-to-point link */
-#define	IFF_KNOWSEPOCH	0x20		/* (i) calls if_input in net epoch */
+#define	IFF_NEEDSEPOCH	0x20		/* (i) calls if_input w/o net epoch */
 #define	IFF_DRV_RUNNING	0x40		/* (d) resources allocated */
 #define	IFF_NOARP	0x80		/* (n) no address resolution protocol */
 #define	IFF_PROMISC	0x100		/* (n) receive all packets */
@@ -179,7 +179,7 @@ struct if_data {
 #define	IFF_CANTCHANGE \
 	(IFF_BROADCAST|IFF_POINTOPOINT|IFF_DRV_RUNNING|IFF_DRV_OACTIVE|\
 	    IFF_SIMPLEX|IFF_MULTICAST|IFF_ALLMULTI|IFF_PROMISC|\
-	    IFF_DYING|IFF_CANTCONFIG|IFF_KNOWSEPOCH)
+	    IFF_DYING|IFF_CANTCONFIG|IFF_NEEDSEPOCH)
 
 /*
  * Values for if_link_state.
diff --git a/sys/net/if_epair.c b/sys/net/if_epair.c
index e9e1a48b3d58..2afbf786c9c8 100644
--- a/sys/net/if_epair.c
+++ b/sys/net/if_epair.c
@@ -543,7 +543,6 @@ epair_setup_ifp(struct epair_softc *sc, char *name, int unit)
 	ifp->if_dname = epairname;
 	ifp->if_dunit = unit;
 	ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
-	ifp->if_flags |= IFF_KNOWSEPOCH;
 	ifp->if_capabilities = IFCAP_VLAN_MTU;
 	ifp->if_capenable = IFCAP_VLAN_MTU;
 	ifp->if_transmit = epair_transmit;
diff --git a/sys/net/if_ethersubr.c b/sys/net/if_ethersubr.c
index 839bae8e9d43..dd5c07acf634 100644
--- a/sys/net/if_ethersubr.c
+++ b/sys/net/if_ethersubr.c
@@ -56,6 +56,9 @@
 #include <sys/sockio.h>
 #include <sys/sysctl.h>
 #include <sys/uuid.h>
+#ifdef KDB
+#include <sys/kdb.h>
+#endif
 
 #include <net/ieee_oui.h>
 #include <net/if.h>
@@ -813,7 +816,27 @@ ether_input(struct ifnet *ifp, struct mbuf *m)
 	struct mbuf *mn;
 	bool needs_epoch;
 
-	needs_epoch = !(ifp->if_flags & IFF_KNOWSEPOCH);
+	needs_epoch = (ifp->if_flags & IFF_NEEDSEPOCH);
+#ifdef INVARIANTS
+	/*
+	 * This temporary code is here to prevent epoch unaware and unmarked
+	 * drivers to panic the system.  Once all drivers are taken care of,
+	 * the whole INVARIANTS block should go away.
+	 */
+	if (!needs_epoch && !in_epoch(net_epoch_preempt)) {
+		static bool printedonce;
+
+		needs_epoch = true;
+		if (!printedonce) {
+			printedonce = true;
+			if_printf(ifp, "called %s w/o net epoch! "
+			    "PLEASE file a bug report.", __func__);
+#ifdef KDB
+			kdb_backtrace();
+#endif
+		}
+	}
+#endif
 
 	/*
 	 * The drivers are allowed to pass in a chain of packets linked with
diff --git a/sys/net/if_infiniband.c b/sys/net/if_infiniband.c
index 30f014ee669d..a11b8a8f5c56 100644
--- a/sys/net/if_infiniband.c
+++ b/sys/net/if_infiniband.c
@@ -25,6 +25,7 @@
 
 #include "opt_inet.h"
 #include "opt_inet6.h"
+#include "opt_kbd.h"
 
 #include <sys/cdefs.h>
 __FBSDID("$FreeBSD$");
@@ -38,6 +39,9 @@ __FBSDID("$FreeBSD$");
 #include <sys/module.h>
 #include <sys/socket.h>
 #include <sys/sysctl.h>
+#ifdef KDB
+#include <sys/kdb.h>
+#endif
 
 #include <net/bpf.h>
 #include <net/ethernet.h>
@@ -417,7 +421,27 @@ infiniband_input(struct ifnet *ifp, struct mbuf *m)
 	int isr;
 	bool needs_epoch;
 
-	needs_epoch = (ifp->if_flags & IFF_KNOWSEPOCH) == 0;
+	needs_epoch = (ifp->if_flags & IFF_NEEDSEPOCH);
+#ifdef INVARIANTS
+	/*
+	 * This temporary code is here to prevent epoch unaware and unmarked
+	 * drivers to panic the system.  Once all drivers are taken care of,
+	 * the whole INVARIANTS block should go away.
+	 */
+	if (!needs_epoch && !in_epoch(net_epoch_preempt)) {
+		static bool printedonce;
+
+		needs_epoch = true;
+		if (!printedonce) {
+			printedonce = true;
+			if_printf(ifp, "called %s w/o net epoch! "
+			    "PLEASE file a bug report.", __func__);
+#ifdef KDB
+			kdb_backtrace();
+#endif
+		}
+	}
+#endif
 
 	CURVNET_SET_QUIET(ifp->if_vnet);
 	if (__predict_false(needs_epoch))
diff --git a/sys/net/iflib.c b/sys/net/iflib.c
index aa16e5d5492b..d056570d9a99 100644
--- a/sys/net/iflib.c
+++ b/sys/net/iflib.c
@@ -6010,7 +6010,7 @@ iflib_register(if_ctx_t ctx)
 	if_settransmitfn(ifp, iflib_if_transmit);
 #endif
 	if_setqflushfn(ifp, iflib_if_qflush);
-	iflags = IFF_MULTICAST | IFF_KNOWSEPOCH;
+	iflags = IFF_MULTICAST;
 
 	if ((sctx->isc_flags & IFLIB_PSEUDO) &&
 		(sctx->isc_flags & IFLIB_PSEUDO_ETHER) == 0)
diff --git a/sys/ofed/drivers/infiniband/ulp/ipoib/ipoib_main.c b/sys/ofed/drivers/infiniband/ulp/ipoib/ipoib_main.c
index 8b2f4724d2fd..fe4581e456d3 100644
--- a/sys/ofed/drivers/infiniband/ulp/ipoib/ipoib_main.c
+++ b/sys/ofed/drivers/infiniband/ulp/ipoib/ipoib_main.c
@@ -922,8 +922,8 @@ ipoib_intf_alloc(const char *name, struct ib_device *hca)
 	}
 	if_initname(dev, name, priv->unit);
 	if_setflags(dev, IFF_BROADCAST | IFF_MULTICAST);
-	if (hca->attrs.device_cap_flags & IB_DEVICE_KNOWSEPOCH)
-		if_setflagbits(dev, IFF_KNOWSEPOCH, 0);
+	if ((hca->attrs.device_cap_flags & IB_DEVICE_KNOWSEPOCH) == 0)
+		if_setflagbits(dev, IFF_NEEDSEPOCH, 0);
 
 	infiniband_ifattach(priv->dev, NULL, priv->broadcastaddr);