[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
RE: [RRG] Six/One Router: Provider-Independence, IPv4/IPv6 Interworking, Backwards-Compatibility
% 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.
to unsubscribe send a message to email@example.com 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