On Aug 19, 2010, at 3:00 PM, Thomas Narten wrote: > Jared Mauch <ja...@puck.nether.net> writes: > > >> On Aug 16, 2010, at 5:43 AM, Mark Smith wrote: > >>> It seems to me that arguing against redirects is actually arguing for >>> having a common case, rather than an transient one, of nodes that don't >>> have full onlink prefix knowledge. I think having all nodes attached to >>> the link (i.e. both hosts and routers) being fully aware of all onlink >>> prefixes is a much better idea. > >> Not really, it's about the role of a device in a network.
>> If there are multiple subnets within a single broadcast domain that >> require redirects to tell the hosts about what is on-link, it's >> much better to actually configure your host correctly (or have it >> actively participate vs passively via redirects) so they have >> knowledge of these additional subnets. > > The above is not the main reason for redirects. > > If you have 2 routers on the link, a host will choose one (at random) > and forward traffic to it. If the host guesses wrong (for a particular > destination), the router should send a redirect directing the host to > use the other router instead (for that particular destination). The > host then updates its cache and forwards subsequent traffic to proper > router. > > Redirects are a key part of the Internet architecture. Always have > been. Not sure if you actually looked at the configuration sampling I posted, but redirects are not actually used in networks these days. The only places where i've seen it used are in "hacked together" networks and were removed. While perhaps useful in the 80's and early 90's, there have been numerous cases where redirects have been harmful to networks that I've operated. If you missed the configuration excerpt I posted, I can send it again to you in private. - Jared (who thinks suggesting that cidr was an key part of the internet infrastructure at one point surely means it's a good idea today too). -------------------------------------------------------------------- IETF IPv6 working group mailing list ipv6@ietf.org Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
