All things related to multicast

[Dan Oachs <>]

One issue we discovered was that not all of our lab computers had the 
same network connection speed.  While they all had 10/100 network cards, 
a couple of them auto negotiated down to 10/half duplex.  This caused 
the entire multicast to slow down to the lowest common denominator and 
thus took a much longer time.  So you might want to double check that 
all the computers you are imaging are actually running at the right 
network speed.  All it would take is one computer to slow them all down.

   Thanks,
      Dan Oachs

Ying Zhang wrote:
> Hello all,
>  
> In our university, we using Novell ZENworks preboot services to image 
> thousands of lab computers. We found if use unicast to do imaging, it 
> takes about 30 minutes for each client, while using 
> multicast takes hours to image a lab with 20+ machines. And the time 
> increases proportionally with the number of machines. What is strange 
> about this is it takes a lot longer to do multicast, no matter how 
> many clients are being imaged.
>  
> The server and clients are on the same VLAN. So no multicast routing 
> is involved. IGMP is enabled on the switch. It uses group address 
> 231.164.242.170. Just wondering if any other universities have similar 
> experience and what could be done on the network side to improve the 
> performance. Any help is appreciated.
>  
> Ying
> UNB

Attachment: smime.p7s
Description: S/MIME Cryptographic Signature