const net.sysARPHardwareGREIPv6

2 uses

	net (current package)
		interface_linux.go#L55: 	sysARPHardwareGREIPv6  = 823 // any over GRE over IPv6 tunneling
		interface_linux.go#L74: 				case sysARPHardwareIPv6IPv6, sysARPHardwareGREIPv6: