Should routers send redirects by default?

Sat Aug 21 14:12:47 UTC 2010

Eric J. Katanich wrote:
> 
> You disable it on the host and if no host is using it, you might as well 
> disable it on the router as wel. Others mentioned
> some routers need to handle this in software instead of hardware, which 
> is obviously slower.

Most redirects are limited in their rate, so it generally is unnoticed 
on the router, but yes, to be fully optimized, turning it off isn't a 
bad idea. Here's a better one. Put the router's choice in the RA on a 
per prefix basis (and of course DHCPv6 for non-RA setups).

Any router/host communication agreements really should have a profile 
setup. If the router is acting in a certain way, it should be able to 
notify the host. If RA is disabled and a pure DHCPv6 setup was deployed, 
obviously the DHCPv6 server would need to provide the necessary router 
information (mtu, icmp unreachable support, etc).

It bugs me that we setup automation support such as between routers and 
hosts and don't include all the different details that both really 
should agree on (such as icmp redirects, or even the ability to push 
routes to hosts, ie modify redirects to support prefix or host based 
redirects since we are starting over here).

Jack