diff --git a/sys/net/if_tuntap.c b/sys/net/if_tuntap.c
--- a/sys/net/if_tuntap.c
+++ b/sys/net/if_tuntap.c
@@ -976,7 +976,8 @@
 	ifp->if_ioctl = tunifioctl;
 	ifp->if_flags = iflags;
 	IFQ_SET_MAXLEN(&ifp->if_snd, ifqmaxlen);
-	ifp->if_capabilities |= IFCAP_LINKSTATE;
+	ifp->if_capabilities |= 
+	    IFCAP_LINKSTATE | IFCAP_RXCSUM | IFCAP_RXCSUM_IPV6;
 	ifp->if_capenable |= IFCAP_LINKSTATE;
 
 	if ((tp->tun_flags & TUN_L2) != 0) {
@@ -1789,6 +1790,24 @@
 		return (0);
 	}
 
+	switch (ntohs(eh->ether_type)) {
+	case ETHERTYPE_IP:
+		if (ifp->if_capenable & IFCAP_RXCSUM) {
+			m->m_pkthdr.csum_flags |=
+			    CSUM_IP_CHECKED | CSUM_IP_VALID;
+			m->m_pkthdr.csum_flags |=
+			    CSUM_DATA_VALID | CSUM_SCTP_VALID | CSUM_PSEUDO_HDR;
+			m->m_pkthdr.csum_data = 0xffff;
+		}
+		break;
+	case ETHERTYPE_IPV6:
+		if (ifp->if_capenable & IFCAP_RXCSUM_IPV6) {
+			m->m_pkthdr.csum_flags |=
+			    CSUM_DATA_VALID_IPV6 | CSUM_SCTP_VALID | CSUM_PSEUDO_HDR;
+			m->m_pkthdr.csum_data = 0xffff;
+		}
+		break;
+	}
 	/* Pass packet up to parent. */
 	CURVNET_SET(ifp->if_vnet);
 	NET_EPOCH_ENTER(et);