[VLAN] VLANs and Network Emulation

[Hazelsnitzel]

Greetings,

My task leader wants to use a 24-port Cisco Catalyst 2950 in 
conjunction with a Linux box to emulate multiple low-speed links, but 
I am too much of a novice at networking and VLANs to know whether his 
idea is feasible.

We currently emulate a single low-speed link by interposing a Linux 
box with two NICs between the endpoints on the link.  We use the 
Linux box as a bridge and use Linux traffic control (i.e., tc HTB or 
TBF) and "Netem" to emulate link characteristics. Eleven Linux boxes 
would be required to emulate 11 low-speed links.  My task leader's 
idea is to use a single "one-armed" Linux box and the 24-port 2950 to 
emulate up to 11 links.

The intranet in our lab uses OSPF and we are not allowed to increase 
the number of router advertisements, so we can't use the Linux box as 
a router.  However, if this constraint were removed, I assume (#1) 
that we still couldn't use the Linux box as a router because both 
endpoints of each link are always in the same subnet.  Is this 
assumption correct?

I also assume (#2) that we can't use the Linux box as a bridge.  I 
assume that if the traffic emanating from the bridge were simply 
returned to it on a trunked link, it would only forward frames to the 
destination if the source and destination MAC addresses were in the same VLAN.

I would like to know if my two assumptions are correct and whether 
anyone has a suggestion about how to solve this problem.  Could it be 
done by developing some custom forwarding software?   If so, what 
would be required?

Thanks,

Bob