Hazelsnitzel wrote: > 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? It can be done. We offer a product based on VLANs and our (non-open-source) network emulation tool. I'm not sure if netem can be used in bridge mode though... Here's a link to our 48-port network emulator product sheet (we offer other quantities of ports as well): http://www.candelatech.com/lanforge_v3/ct970_product.html The diagram shows one LANforge machine and one bridge machine, but we can now do all of this in a single machine for a more efficient use of hardware. If you are interested in more information related specifically to LANforge, please contact me directly (greearb@xxxxxxxxxxxxxxx). Thanks, Ben > > Thanks, > > Bob > > _______________________________________________ > Vlan mailing list > Vlan@xxxxxxxxxxxxxxx > http://www.candelatech.com/mailman/listinfo/vlan -- Ben Greear <greearb@xxxxxxxxxxxxxxx> Candela Technologies Inc http://www.candelatech.com
