I export a query on a computer IP is 58.60. . , And then use the tracert command to query paths ping Baidu, and found that there is no path to the same network segment (ie 58.60. Beginning), why is this?
This problem, there are two possibilities:
(1) the operator assigned to the customer is a public network IP = 58.60.xx
(2) the operator is assigned to the user's non-public network IP, when the user traffic into the Internet, using a public network IP = 58.60.xx do NAT
These two cases are possible when traceroute, no hop IP and 58.60.xx in a subnet on the network path. Then analyze these two situations:
I.
Usually the user using PPPoE dial-up Internet access, IP assigned as 58.60.xx / 32, 32-bit mask length, so what good is it? IP is not a waste of resources! Ask students a question, PPPoE interface is a broadcast interface or point to point interface type?
Yes, the interface point to point, point to point interface requires both parties to communicate in a network, right? You do not need! Why is point to point interface? Look at packaging format it:
Ethernet/PPPoE/PPP/IP/IP Payload
Because all IP packets sent from the LAN MAC aim is PPPoE Server, the source MAC all, this is not a typical point to point interface features home router it? Okay, commercial operators to terminate PPPoE client interface requires an IP address, right? Of course, need, can be any IP, as long as the IP interface configuration can work, in order to save IP, IP can usually borrow other interfaces, such as "IP unnumbered"
Dial successful client will generate two routes:
0.0.0.0/0 PPPoE
58.60.x.x/32 PPPoEUse when accessing Internet 0.0.0.0/0 route, because it is point to point interface, it does not care about how much the next hop IP, right? So the main problem appears describing the phenomenon is not surprising.
Scenario 2
When the user's traffic went to Internet, you need to do NAT, then the public IP come from? Borrowing from the interface of a router do? Yes, but the expansion is not high enough, after all, on a IP.
How high does it extend? Using a public IP network resource pool, the pool can be an IP, it can be any number of completely depends on demand.
Okay, that these pool of public IP must be configured on the interface it? You do not need!
Since 58.60.xx There is not configured on any interface, then when you traceroute, this NAT device that is directly connected to the router interface IP, there may not be entirely 58.60.xx. That when you traceroute to the NAT device, due 58.60.xx not configured on any interface, so naturally not to send an error message using traceroute 58.60 address!