Re: Hardware capture platforms

["Larry J. Blunk" <ljb () merit edu>]

Warren Kumari wrote:
> On Jul 29, 2008, at 10:43 PM, Darryl Dunkin wrote:
>
> > Hubs sure are fun...
>
> This might be a stupid question, but where can one get small hubs 
> these days? All of the common commodity (eg:  4 port Netgear) "hubs" 
> these days are actually switches.
>
> What I am looking for is:
> Small enough to live in my notebook bag (e.g.: 4 port with a wall wart.)
> Cheap
> Simple
> 10/100/1000Mbps
>
> While a tap would work, I'd prefer a hub because I can then use it to 
> connect machines together in a pinch.

   D-Link sells a smallish 8-port managed Gigabit switch that allows
you to disable learning on the ports --  DGS-3200-10 --
http://www.dlink.com/products/?sec=0&pid=674
I don't know where they hide the manuals on the D-Link
US site, but Google turned them up on their Russian ftp server ??
While not incredibly cheap, it seems reasonable at about $300.
As a bonus, it seems to have pretty complete IPv6 support.

  We wanted to do something similar with a 10G switch (SMC8708L2).
It let's you set the size of the MAC table, but not to zero.   However,
we found that setting the size of the table to 1 entry effectively disabled
learning.


> W
> ---
>
> In the past I have bought some cheap 4 port commodity switches (form 
> Circuit City or somewhere similar), found the datasheet for the 
> chipset (it was a Broadcom something or other) and tied the pin to 
> ground that disables the learning mode (actually, I think that the pin 
> just set the size of the learning table to be 0 entries).  While this 
> works, doing it once was more than enough :-)
    Nice hack!