IPNETIF_IPV6PLUMBED
isv6 ? IPNETIF_IPV6PLUMBED : IPNETIF_IPV4PLUMBED;
ipnetif->if_flags &= isv6 ? ~IPNETIF_IPV6PLUMBED : ~IPNETIF_IPV4PLUMBED;
if (!(ipnetif->if_flags & (IPNETIF_IPV4PLUMBED | IPNETIF_IPV6PLUMBED)))
isv6 ? IPNETIF_IPV6PLUMBED : IPNETIF_IPV4PLUMBED;
if (ipnetif->if_flags & IPNETIF_IPV6PLUMBED) {