On Tue, Oct 9, 2012 at 1:27 PM, Nirmalya Lahiri <nirmalyalah...@yahoo.com> wrote:
> For a experimental purpose yesterday I have ping to 192.168.2.10... It > should not return reply. But unfortunately I got reply from a host. After > investigation I have found that the host is outside of my local network. > Please look into the tracepath report from my local PC to that unknown host. > > nirmalya@nirmalya-desktop:~$ tracepath 192.168.2.10 > 1: nirmalya-desktop.local (192.168.7.103) 0.141ms pmtu 1500 > 1: 192.168.7.51 (192.168.7.51) 0.706ms > 1: 192.168.7.51 (192.168.7.51) 0.700ms This looks like the LAN interface of your gateway. > 2: 115.115.147.137 (115.115.147.137) 150.228ms This is the IP at the far end of your leased line connection. > 3: 121.240.2.54 (121.240.2.54) 188.099ms asymm 6 > 4: 121.240.2.57 (121.240.2.57) 175.322ms asymm 6 Your packet goes into a "public" network segment. > 5: 172.25.81.133 (172.25.81.133) 176.625ms asymm 6 > 6: 172.29.253.34 (172.29.253.34) 208.708ms asymm 8 > 7: 172.31.16.193 (172.31.16.193) 186.462ms asymm 8 > 8: 172.31.35.138 (172.31.35.138) 206.554ms asymm 10 > 9: 172.31.8.134 (172.31.8.134) 226.454ms asymm 10 > 10: 172.25.82.62 (172.25.82.62) 206.389ms asymm 9 > 11: 192.168.2.10 (192.168.2.10) 217.967ms reached and then it traverses through a private "network segment" within the public network segment. To you the "Public" network segment is the ISP. I have seen this technique being used since the early days of consumer ISPs (c. 1994). It is an efficient usage of a scarce resource i.e. IPv4 numbers. Expect to see more and more ISPs adopting this technique within the "ISP" cloud. When you traceroute to 8.8.8.8 (which is outside the ISP's cloud), you will see the egress point from the ISP with a "public" IP number. -- Arun Khan _______________________________________________ Ilugd mailing list Ilugd@lists.linux-delhi.org http://frodo.hserus.net/mailman/listinfo/ilugd
