diff --git a/share/man/man4/ixl.4 b/share/man/man4/ixl.4
--- a/share/man/man4/ixl.4
+++ b/share/man/man4/ixl.4
@@ -31,7 +31,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd June 27, 2020
+.Dd January 19, 2021
 .Dt IXL 4
 .Os
 .Sh NAME
@@ -227,6 +227,15 @@
 Displays the current speed.
 .It Va dev.ixl.#.fw_version
 Displays the current firmware and NVM versions of the adapter.
+.It Va dev.ixl.#.debug.switch_vlans
+Set the Ethertype used by the hardware itself to handle internal
+services.
+Frames with this Ethertype will be dropped without notice.
+Defaults to
+.Dv 0x88a8 ,
+which is a well known number for IEEE 802.1ad VLAN stacking.
+If you need 802.1ad support, set this number to any another Ethertype i.e.
+.Dv 0xffff .
 .El
 .Sh INTERRUPT STORMS
 It is important to note that 40G operation can generate high
diff --git a/sys/dev/ixl/ixl_pf_main.c b/sys/dev/ixl/ixl_pf_main.c
--- a/sys/dev/ixl/ixl_pf_main.c
+++ b/sys/dev/ixl/ixl_pf_main.c
@@ -69,6 +69,7 @@
 static int	ixl_sysctl_sw_filter_list(SYSCTL_HANDLER_ARGS);
 static int	ixl_sysctl_hw_res_alloc(SYSCTL_HANDLER_ARGS);
 static int	ixl_sysctl_switch_config(SYSCTL_HANDLER_ARGS);
+static int	ixl_sysctl_switch_vlans(SYSCTL_HANDLER_ARGS);
 static int	ixl_sysctl_hkey(SYSCTL_HANDLER_ARGS);
 static int	ixl_sysctl_hena(SYSCTL_HANDLER_ARGS);
 static int	ixl_sysctl_hlut(SYSCTL_HANDLER_ARGS);
@@ -2329,6 +2330,11 @@
 	    CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_NEEDGIANT,
 	    pf, 0, ixl_sysctl_switch_config, "A", "HW Switch Configuration");
 
+	SYSCTL_ADD_PROC(ctx, debug_list,
+	    OID_AUTO, "switch_vlans",
+	    CTLTYPE_INT | CTLFLAG_WR | CTLFLAG_NEEDGIANT,
+	    pf, 0, ixl_sysctl_switch_vlans, "I", "HW Switch VLAN Configuration");
+
 	SYSCTL_ADD_PROC(ctx, debug_list,
 	    OID_AUTO, "rss_key",
 	    CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_NEEDGIANT,
@@ -3481,6 +3487,40 @@
 	return (error);
 }
 
+static int
+ixl_sysctl_switch_vlans(SYSCTL_HANDLER_ARGS)
+{
+	struct ixl_pf *pf = (struct ixl_pf *)arg1;
+	struct i40e_hw *hw = &pf->hw;
+	device_t dev = pf->dev;
+	int requested_vlan = -1;
+	enum i40e_status_code status = 0;
+	int error = 0;
+
+	error = sysctl_handle_int(oidp, &requested_vlan, 0, req);
+	if ((error) || (req->newptr == NULL))
+	    return (error);
+
+	if ((hw->flags & I40E_HW_FLAG_802_1AD_CAPABLE) == 0) {
+		device_printf(dev, "Flags disallow setting of vlans\n");
+		return (ENODEV);
+	}
+
+	hw->switch_tag = requested_vlan;
+	device_printf(dev,
+	    "Setting switch config to switch_tag=%04x, first_tag=%04x, second_tag=%04x\n",
+	    hw->switch_tag, hw->first_tag, hw->second_tag);
+	status = i40e_aq_set_switch_config(hw, 0, 0, 0, NULL);
+	if (status) {
+		device_printf(dev,
+		    "%s: aq_set_switch_config() error %s, aq error %s\n",
+		    __func__, i40e_stat_str(hw, status),
+		    i40e_aq_str(hw, hw->aq.asq_last_status));
+		return (status);
+	}
+	return (0);
+}
+
 static int
 ixl_sysctl_hkey(SYSCTL_HANDLER_ARGS)
 {