On Fri, Feb 4, 2011 at 10:27 AM, Christopher Morrow <[email protected]> wrote: > On Fri, Feb 4, 2011 at 7:21 AM, Roland Bless <[email protected]> wrote: >> Hi, >> >> Christopher Morrow wrote: >>> My feeling is this: >>> hop-by-hop processing will happen in slow-path (if you permit it to >>> happen at all), you can't build a router today with an asic that'll >>> know how to handle options which are created in the future :( >> >> while the latter is surely true, I don't think that this >> argument precludes to implement fast path processing >> of at least _some_ HbH options. I think that the current >> implemented strategy to simply pass all HbH options >> to the slow path CPU is broken. >> >> I'm not sure whether it is feasible, but couldn't the >> Fast Path (ASIC) at least check for: >> - known options to be processed in the fast path, e.g., >> some CONEX info field > > which options? how often would you expect this list to update? routers > live in the network for ~7 years or so, in large networks. ASIC > updates mean very expensive (equipment, personnel, sla) changes are > required. >
Someone reminded me off-list to be clear about what the problem is... Any packet that requires hop-by-hop behavior is a problem. If a backbone router has to attempt to stream packets off a production interface and into the RE/RP/PRP, the router will fall over. So, the operator(s) are left with 2 real options: 1) drop all packets NOT icmpv6, tcp, udp (drop all other extension headers) 2) ignore any extension header NOT icmpv6, udp, tcp It would be grand if router vendors (Juniper, Cisco, Force10, Extreme, Foundry, Huawei, etc) would provide a knob on all of their platforms that said: hbh-options [ignore|drop] This would allow all network operators (enterprise, datacenter, backbone) to decide how to handle traffic with hbh options. I'm sure someone at the vendor of your choice could also add in options to drop/ignore by type of option, though that seems more brittle. (I hope this is more clear :) ) -Chris -------------------------------------------------------------------- IETF IPv6 working group mailing list [email protected] Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
