IP_MAX_MEMBERSHIPS story.

[Robert Watson]

On Tue, 9 May 2006, Bruce M Simpson wrote:

> On Tue, May 09, 2006 at 01:28:01PM +0100, Bruce M Simpson wrote:
>> A user recently reported a problem with running into IP_MAX_MEMBERSHIPS
>> on a system running FreeBSD with IPv4 forwarding enabled, and running
>> the OSPF routing protocol.
>
> More background. People may be wondering why this is even an issue for 
> FreeBSD as a router.
>
> The answer: the imo_membership array contains members which exist as 
> separate entries for each ifnet in the system, and the system where this was 
> observed to be a problem had a number of ifnet interfaces which was larger 
> than IP_MAX_MEMBERSHIPS (20).

I'm loosely of the opinion that the membership array should be variable 
length, and that we should default it to 20, but have a significantly larger 
maximum.  It's not horribly efficient, but also wouldn't be so particularly 
terrible either.

Robert N M Watson