% Would be interesting to find out how prevalent routers with slow-path % processing of IPv4 header options are in the DFZ.
Nearly all IPv4 routers of all types shunt any packet containing any IPv4 option via CPU-based slow-path forwarding. I do not myself know of even 1 exception to this. DFZ routers would not generally be an exception to this. In most cases, what happens is a header length check -- if the header length is anything other than minimal legal IPv4 header size then the packet goes to the CPU and leaves the hardware (or software) fast path forwarding. % IPv6 Destination Options headers that are not used % for source routing are not looked at by routers. s/are not looked/should not be looked/ One might want to run the experiment with some real routers to verify the actual behaviour. Ours ought not look at stuff inside an IPv6 Destination Option, but I haven't verified this experimentally or by looking at source code (I am in research, and am not working on products.) I have no real idea either way what other implementations might have done in this area. Cheers, Ran -- to unsubscribe send a message to [EMAIL PROTECTED] with the word 'unsubscribe' in a single line as the message text body. archive: <http://psg.com/lists/rrg/> & ftp://psg.com/pub/lists/rrg
