[K12OSN] Tuning LTSP Performance

[Terrell Prude' Jr.]

Robert Arkiletian wrote:
> 2008/8/29 Terrell Prude' Jr. <microman at cmosnetworks.com>:
>   
>> 2.)  If you're running LTSP of any sort, it's assumed that you're running,
>> at a minimum, a switched 10/100 environment (if not, then you really should
>> be!).  Unless A.) it's a managed switch capable of port mirroring, and B.)
>> you control said switch, you can sniff *your* traffic, but not other
>> peoples.  To keep the Les Mikesells of the world happy, I'll point out that
>> yes, you could sniff the server if it's physically accessible.  But in God's
>> name, I hope you have it secured physically so's to (largely) prevent that!
>>     
>
> Please enlighten me Terrell. I don't understand how having access to
> the server is a vulnerability in terms of sniffing packets. One must
> have root access to be able to use a program like tcpdump or wireshark
> to capture packets. So if they don't have root how can they sniff?
>   

Easy.  Say you're a "curious" kid.  :-)  Just insert your own switch 
(yes, they're available on eBay) in between the server and its network 
drop.  On your switch, mirror the port to your laptop (laptop HD's are 
pretty big nowadays).  Boom, you've done it, and no, it ain't that hard 
to do.  I do this sort of thing regularly at work as part of my network 
engineer duties when troubleshooting certain problems.

However, if the server's physically secured, then very likely its 
network drop is also physically secured, if it's a standard building.  
Thus, it becomes, obviously, much more difficult to insert any gear in 
between the LTSP server and its network drop.

--TP