As written in the RFC 791 this option is useful to record the addresses of the routers that an ip datagram goes through.

I'm sending an ip datagram with an ICMP echo message, i've set the option type (of the header ip) on 7, the option length on 7 and the pointer on 4.

I expect an echo reply with the first router address to come back, but this doesn't happends. Am i doing something wrong or the option is not supported anymore?(If i don't set the options, the echo response comes back as expect)

closed as off-topic by Stephane, TheJulyPlot, Teun Vink, Serge Ballesta, Xander Jun 13 '17 at 15:15

This question appears to be off-topic. The users who voted to close gave this specific reason:

  • "This question does not appear to be about Information security within the scope defined in the help center." – Stephane, Teun Vink, Serge Ballesta, Xander
If this question can be reworded to fit the rules in the help center, please edit the question.


It is not uncommon for this option to be blocked by ISPs. Since you are getting no route information at all, the router closest to you (i.e. your home or office router) is probably black-holing those packets. If you can reconfigure that device, you may well find that you can get little or no more information from downstream for the same reason.

Not the answer you're looking for? Browse other questions tagged or ask your own question.