sharing multiple uplinks between N clients

[Mamonetti]

Hi

I'm planning to get a new switch in order to share 1 or more DSL  uplinks between a set of neighbours, and I'd like to know if it is doable, and which switch should I choose for it.

So.. take a look at this:

http://img375.imageshack.us/img375/5691/esquemaswitchpiso.jpg

The  idea is quite simple, split each uplink between N ports, but at the  same time allow them to communicate each other at full speed internally.

Related  to the bandwitch control it should be done for each "link" between  every port and its own WAN port (P01 for VLAN1, P09 for VLAN2 and P17  for VLAN3). A reasonable downspeed limit would be close to 1 Mbps or higher per port.

So:
- Can I add a WAN port to each VLAN?
-  Can I really control the bandwitch the way I like?

Regards

[lgijssel]

No, it won't work.

You are in fact building one layer2 network using 4 vlans internally and with 3 parallel routers to the Internet.

There is no guarantee that hosts in vlan 1 will be serviced by the dhcp server in R1, they may just as well get an ip from one of the other routers.

The design will only work for different ip subnets and routing internally via a layer3 switch.

Load sharing for www is best effort by default.

Merry Christmas!

Leo

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[Mamonetti]

Why not? P09 and P17 should not be reachable by P2-P8, so they should not receive DHCP responses from them (those ports are not reachable to DHCP requests). Same with the other VLANs.

So.. afaik this should work. I can try in a demo scenario, I think i can get a VLAN capable switch to test this.

From the bandwitch limit point of view, is it doable? I mean, there are other switch provides with support for this stuff, related to IP traffic, so i doubt Cisco doesn't allow this in some of its switches (for example D-Link has some models with bandwitch limit support).

Regards

[Mamonetti]

Ok, after doing some search I've found the reason: having a port in multiple VLAN's requires it to be tagged, and in my scenario it means tagging almost all the ports, which will be a problem as long as it is not transparent for the PC's that should be connected on each port.

Anyway, I don't understand why tagging is required if you want to have a port in multiple VLAN's. For example, if P02 sends any packet it should be sent at most to everyone in VLAN 1 and VLAN 4, no more no less. Why tagging is needed? I don't know, but for me it looks like a software restriction. In the end this is not a hardware issue at all.

Regards