[Linux-cluster] network best practice for cluster?

[FM]

Hello,

We read a lot of gfs tuning, number of nodes, etc. But how about the 
network infrastructure ?

is a separate network/vlan for dlm is the way to go ? Do you tune the 
network stack to speed dlm ?

In my server room, it is very simple :
GFS-1
2 directors behind the firewall (using NAT).
and 5 nodes behind them with 2 nicks (using bonding). All requests and 
dlm network traffic are using the same network (and the same bonded card).
The network is Gb

I am very curious to know the best practice ! The cluster is working 
great (especilly since the introduction of the glock_purge parameter) 
but there is always room for improvement !

regards,