On Wed, 25 Oct 2017 22:45:42 +0200 Max Grobecker <max.grobec...@ml.grobecker.info> wrote:
> But: When I lookup this IP address on https://stat.ripe.net/073.000.255.229 > the first octet is internally getting swapped to "59". > This can be explained, if you take "073" as an octal value and convert it to > a decimal value. > It is definitely a octal-to-decimal conversion thing, as for example also the > value "010" is getting replaced by "8" and so on. > > Now I'm puzzled: Of course, writing IPv4 octets with leading zeroes is not > very common. > But: Is it officially prohibited or discouraged? > > This weird conversion also happens inside the "geoiplookup" tool by MaxMind > and I'm not sure if I'm going to be the moron in this story > or if I found the same bug inside multiple softwares at once ;-) There are many ways to write an IP address, and yes, leading zeroes mean the octal form. Even basic utilities like "ping" use this conversion: $ ping 010.020.030.040 PING 010.020.030.040 (8.16.24.32) 56(84) bytes of data. ^C --- 010.020.030.040 ping statistics --- 1 packets transmitted, 0 received, 100% packet loss, time 0ms Another way is to give a full 32-bit number as integer: $ ping 728374928 PING 728374928 (43.106.30.144) 56(84) bytes of data. ^C --- 728374928 ping statistics --- 2 packets transmitted, 0 received, 100% packet loss, time 1015ms Or you can skip zeroes (almost like in IPv6): $ ping 10.9 PING 10.9 (10.0.0.9) 56(84) bytes of data. ^C --- 10.9 ping statistics --- 2 packets transmitted, 0 received, 100% packet loss, time 1015ms So what you found is not a bug, but a common behavior. I'm sure all of this is described in great detail in some 40 year old RFC. -- With respect, Roman
