ICMP Traceback - Backlink problem?

Lee Chee-Jwai Henry <[email protected]> Tue, 06 May 2003 12:57:21 +0800
Newsgroups gmane.ietf.itrace
Message-ID <[email protected]>
On the latest draft 04 on ICMP Traceback, I have the following query:

ICMP Traceback may contain either forward link, back link or both. I can see how the destination node reconstructs the path using forward link exclusively but I do not see how the same can be done using backlinks. 

In the case of forward link, the "glue" that links up two link segments is the source address of the ICMP packet, which "SHOULD be that associated with the interface on which the packet arrived", will then correspond to the destination address of the forward link generated by the upstream router. 

In backlink case, if the routers use the same source address setting, how then can the various backlinks segments be "glued" together? 

Regards. 
Henry


Dr. Henry Chee-Jwai, LEE
Institute for Infocomm Research (I2R)
21 Heng Mui Keng Terrace
Singapore 119613
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Email: [email protected]