I'd go with the 802.1q Trunked backbone. It gives you the flexibility of spanning vlans across a network. As for point 3 how about a virtual vlan interface on one of the 6509. If you have ample capacity over your backbones I don't see a problem on where the virtual vlan is to be terminated also with subinterfaces you run the risk of oversubscribing the actual physical interface bandwidth. hope I'm making sense!
Terry Rupeni -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Rick Kunkel Sent: Tuesday, 9 February 2010 7:08 AM To: [email protected] Subject: [c-nsp] Using switchport 802.1q for a point-to-point instead of routed /30 Hello all... Right now, I've got a bunch of customers connected to a bunch of switchports using different VLANs. I've got 802.1q running between the switches, and then a router attached with a bunch of subinterfaces, one for each VLAN. Assigned to each of these subinterfaces is the customer's gateway IP address. So, for instance, have something like this for the customer port interface FastEthernet 1/12 switchport access vlan 80 Then the switch is connected to a router, with an interface like this interface GigabitEthernet 0/1.80 encapsulation dot1Q 80 ip address X.X.X.2 255.255.255.252 Pretty standard stuff.... So, now, we're opening another location, and we've got some customers interested in having some equipment in the first location and some in the second, and having it all be part of the same network. The connection between the two location is ethnernet, and the hardware is (well, will be as soon as we upgrade out of a 7200) a 6509 on either side, and I think it'd be pretty cool to run an 802.1q trunk between them using 6509 switchports instead of routed ports. However, I've got some problems, or at least I'm having trouble wrapping my brain around some things... 1. In the interests of keeping things simple, is it a "bad" idea to use an 802.1q trunk for backbone connectivity? 2. I'd normally set up this kind of point-to-point link using a /30, using interfaces in "routed" mode, and assigning the addresses to the interfaces on each end of the link. If using and 802.1q trunk with interafaces in "switchport" mode, would it be advisable to use loopback interfaces for these addresses instead? 3. I'm used to having the customer's gateway set on that Gigabit subinterface, as above. But if I want this customer to have their stuff on the same VLAN in both locations, AFAIK, I should set switchport access VLAN 80 on both their access ports. I'm then stuck figuring out where to put the gateway address for their IP space. Again, would loopback interfaces be good candidates for this? Or perhaps a VLAN interface, as weird as that seems to me? 4. My motivation for doing any of this in the first place, as opposed to a simple /30 point-to-point interface, is to allow customers to have access to layer 2 across our network, whether it be for internal use or for purchasing third-party connectivity. Is it "acceptable" to use our single point-to-point ethernet for this, or should I be using a separate network for this entirely? Thanks! Rick _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/ _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
