How to know the various IP addresses of the server using C, Linux, Socket?

Question

I know one IP address of the remote node via. traceroute. However, I want to know all the IP address in its interfaces. How can I do so? The node doesn't have hostname so I can't use the API to get various ifaddress using hostname API. I searched various places but couldn't find on how to get the various IP address of the remote node. Is it possible to get it? Basically, I am implementing traceroute and my aim here is to display the loopback address of the intermediate node and not the actual interface address. In case loopback address is not available, I would like to display the actual interface address. I am struggling here and have no clue on it. This is all implemented using C - linux, UDP socket.

Answer 1

I want to know all the IP address in its interfaces. How can I do so

Lookup DNS or login in and use the OS dependant tools/APIs to lookup the local interfaces' IP addresses, else you are lost.

Answer 2

从技术上讲，如果您在同一网络上，则可以使用macid并嗅探网络流量，以在该接口上找到其他IP，但是一旦离开本地网络，就几乎不可能找到该计算机正在侦听的其他IP。如果他们提供此信息将是一个安全问题。

Answer 3

The way traceroute works is by sending packets with increasing IP TTL values towards a remote address and the routers along the way will generate back ICMP TTL time exceeded thus revealing their IP source address back to the sender and so you get to know the hops that your data might be traversing when attempting to communicate to a specific remote address. The icmp error message will contain the ip address of the hop's incoming interface and in your case you want to discover also all other ip addresses assigned to further outgoing interfaces (outgoing as seen from your sender perspective) but this is not possible by using the above mentioned technique or any other.