as we all know, ping test for a connection eg ping google.com checks for connection between my home and google.com now suppose ping A ping B are being tested . but these tests connection between home to A and between home and B . but how to ping between A and B i.e how to check connection between A and B where A and B may be google.com and yahoo.com thanks in advance

I don't know of a protocol designed to do that. But some time ago a guy named Antirez came with this very clever idea : http://insecure.org/nmap/idlescan.html

Cannot be done, unless you have remote access to one of hosts.

With IP spoofing you could bounce packets between the hosts, but you would never be able to receive the result.

The reason for this is simple: if this were possible, then it would be possible to hijack third party connection for data transfer (ping carries payload as well). Imagine torrent protocol using this to transfer data.

Even more - it would be possible to store data in ether. This would create networked volatile memory, similar to DRAM. And if such third-party routing were possible, these connections could initiate each other. Very interesting concept, but impossible to allow.

The idea is simple: host O sends 64k ping between hosts A and B. The ping results are sent to C, which, using same routing, bounced them between C and D. Ping results of that are sent to hosts A and B. And presto - JK flip flop. All you need now is some way to obtain these results, which could be obtained by some form of dynamic routing table somewhere in between remote hosts. Possibly through DNS update propagation. Such RAM would have several minutes latency on access, but still, ....

A similar concept was proposed several years ago using DNS cache, which allowed for some very interesting concepts, but unfortunately has the capacity to literally break the internet as a whole.

Quote:Original post by Antheus
With IP spoofing you could bounce packets between the hosts, but you would never be able to receive the result.

That is not fully true, as Antirez' paper demonstrates.

Quote:Original post by bulgurmayo

Quote:Original post by Antheus
With IP spoofing you could bounce packets between the hosts, but you would never be able to receive the result.

That is not fully true, as Antirez' paper demonstrates.

The method requires B to be in controlled environment (must not send any packets during scan). This is essentially a remote host you have access to. You also do not receive results, merely an indication something happened, what exactly isn't deterministic.

iam not sure(since iam beginner in networks)
can socket programmimng help in any way to solve my problem??

Quote:Original post by asdfwe
iam not sure(since iam beginner in networks)
can socket programmimng help in any way to solve my problem??

It is impossible to solve due to the way internet protocol is designed.

The only way you can do this, is if you have accesss to either host A or host B (yahoo or google in your example). Then you can either login into one of the hosts and perform the ping from there, or install a "ping service" on one of them and you contact that.

But you need administrator-level access to either host A or host B.

Quote:Original post by Antheus

Quote:Original post by bulgurmayo

Quote:Original post by Antheus
With IP spoofing you could bounce packets between the hosts, but you would never be able to receive the result.

That is not fully true, as Antirez' paper demonstrates.

The method requires B to be in controlled environment (must not send any packets during scan). This is essentially a remote host you have access to. You also do not receive results, merely an indication something happened, what exactly isn't deterministic.

I disagree. The only constraint on what you call B is that is receives almost no traffic at the time you are doing the indirect probe. This is by far a much lesser constraint than requiring it to be a remote host. Moreover I have experimented this technique with success and it never required my having access to any remote host.
You could see for yourself and give it a try using Antirez' tool called hping.

Quote:Original post by bulgurmayo
I disagree. The only constraint on what you call B is that is receives almost no traffic at the time you are doing the indirect probe. This is by far a much lesser constraint than requiring it to be a remote host. Moreover I have experimented this technique with success and it never required my having access to any remote host.
You could see for yourself and give it a try using Antirez' tool called hping.

What's the tracert between www.yahoo.com and www.google.com?