const vendor/golang.org/x/net/dns/dnsmessage.edns0Version

2 uses

	vendor/golang.org/x/net/dns/dnsmessage (current package)
		message.go#L1665: 	edns0Version = 0
		message.go#L1695: 	if h.TTL&ednsVersionMask == edns0Version { // RFC 6891 section 6.1.3