Re: [Tsvwg] WGLC for Port Randomization starts now (April 1st)

[Randy Stewart <[e-mail]>]

For a particular port X you have a limit of 2^32
vtags.. yep..

But the BSD implementation would not support that many simultaneous
connections anyway.. I think we have a sysctl limit of about 40,000
associations... it can be raised... but the default is 40k..

So you might have a hard time rolling over that many associations
in the period of time your talking about.

If you don't keep a timed wait, then you could get old packets
injected on a new association.. for example an ABORT could
be tossed at you from an old association where you re-used
the vtag...


R
On May 28, 2009, at 10:51 AM, Brian F. G. Bidulock wrote:

> Randy,
>
> So, by forming and releasing 2^32 associations within 2MSL I can
> rum you out of vtags?  That might be a lot of memory depending on
> how much memory you use for each vtag in this wait state.  What
> do you do when all of the vtags are in wait state?  Can a new
> association form?
>
> --brian
>
> Randy Stewart wrote:                          (Thu, 28 May 2009  
> 10:39:37)
>>
>> Basically for BSD we take a v-tag used in a connection.. call it  
>> 'X',  and
>> we place just the tag 'X' into a "timed-wait" cache for 2MSL. There  
>> is  no
>> restriction on the socket here.. just the tag 'X' will not be used  
>> again
>> with this socket.
>
> -- 
> Brian F. G. Bidulock
> [e-mail]
> http://www.openss7.org/
>

-----
Randall Stewart
[e-mail]