[c-nsp] Question on passing MAC addresses over switched metro ethernet

Steven Pfister SPfister at dps.k12.oh.us
Wed Dec 14 11:12:12 EST 2011

I've got a situation where several remote sites are connected to a 
central location using AT&T's Customized Switched Metro Ethernet 
(CSME). The core switches at each location are Cisco 4500 series 

The problem is this... each remote site has a server assigned to it, 
which is being implemented as a virtual machine at the central 
location in the vlan belonging to the remote site's core network. The 
AT&T network learns the MAC addresses from each remote site, and the 
switch at the central location learns them from AT&T. This is working 
fine, but AT&T has to learn every MAC addresses from all the remote 
sites. This means we need to make sure they're allowing sufficient 
addresses to cover all the sites, plus they charge according to how 
many they're allowing through. 

I'm trying to research alternatives. Is there any way to pass the MAC 
addresses from the remote site to the switches connecting the VMWare 
servers (6 servers between 2 physical switches) without special setup 
on AT&T's part? If it will require additional hardware, that's fine, 
just need to look at all the options. 
Steve Pfister
Network Engineer
Office of Information Technology
Dayton Public Schools
115 S Ludlow St
Dayton, OH 45402-1812
Phone: 937-542-3149
Cell: 937-673-6779
spfister at dps.k12.oh.us ( mailto:spfister at dps.k12.oh.us )

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