> - return ((uint32)type) << 8 + code; > + return ((uint32)type << 8) + code; Good one. Precedence rules... rulez! > I wonder how that one could have been missed before... Would explained why Yin Qiu failed to upstream port unreachable error. Plus, bad luck, ICMP_TYPE_UNREACH and ICMP_CODE_PORT_UNREACH, the pair of codes reported in such [test]case, are both set to 3... Bye, Philippe.