Creating a new VLAN

[randynieukirk]

Our office connects to our colo, which provides our internet connection.  AT&T limits the number of MAC addresses.  To prevent AT&T from seeing all the MACs on each side of the connection I need to set the switches to route all the VLANS on layer 3. Then all AT&T sees are the MACs of the two (2) connected switch ports.

This is new territory for me, but probably very simple to others. Can anyone provide an example of how this is set up? I have two (2) Cisco 3750s, one (1) at each site.

Thank you for your help!

Randy

[IAN WHITMORE]

OK.

You need to create a new VLAN for use between your switch & AT&T.

i.e. create a new vlan, let's say 100, and assign a small network like 192.168.1.0/30.

You will create a a layer 3 interface and use the IP 192.168.1.1/30, but you have to talk to AT&T because they will need one also with the same VLAN configuration and the IP 192.168.1.2/30 (This could be a problem. If you only have layer 2 now, maybe they have used a device that only supports layer 2. Some service providers do this.). I assume you already have layer 3 interfaces so IP routing is already turned on.

You will need layer 3 interfaces for all your remaining VLANs (you probably have this already because your 3750 will be the default gateway for your PC's I assume).

Then you can set the default route to the AT&T next hop.

Bingo. AT&T will only see the MAC of the directly connected switchport.

HTH,

Ian

[fgasimzade]

If AT&T uses only Layer2 devices, you can just ask them to configure vlan 100 all the way from your office to remote location

Then you just assing IP addresses on your site 192.168.1.1/30 and remote site 192.168.1.2/30 and configure routing between the sites

[Ven Taylor]

Can you just route between your L3 switch and AT&T?  Create a point to point L3 connection between the switch and the AT&T stuff, then create SVIs for each vlan on your switch.  If this is what you're talking about, let me know. I can help.

[randynieukirk]

Ven:

I don't think I can get the required info from AT&T, they may figure out what I am doing to avoid the cost for using more MAC addresses than what they allow.  If I have 1 3750 at the colo and 1 3750 at the office, couldn't I create a VLAN between the point to point and then have the switches do L3 routing for the networks at the colo and the office?

Is this going to be an efficient solution?

Thanks for you rsuggestions, everyone!  PLEASE, keep em coming.

Randy

[fgasimzade]

No, I am afraid it is not possible, because in this case you'll have to configure vlan all the way from your colo to the office through AT&T network