metro-e , e-line, point-to-point networking

king daddy
king daddy used Ask the Experts™

I am setting up a 50 Mb point-to-point circuit (TW calls it a e-line or metro-e) between the office and the datacenter. I currently have a VPN between the two. I also currently have two distinct LAN IP networks (192.168.25 at the office and 192.168.35 at the datacenter).

Do I have to keep two separate IP networks with a point-to-point (metro-e) or can I extend the .25 LAN network from the office to the datacenter since it is a point-to-point?

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As long as this is a true Layer 2 offering, then the pipe is unaware of the layer 3 traffic inside it - and you can extend your LAN using the circuit.
For example, how are you communicating over that pipe right now? What's doing your Layer 3 switching/routing to get from one segment to another?
Best to check with your provider. Metro-e comes in a few flavors.


thanks rharland2009. I have not set it up yet. I have a sonicwall NSA 240 at the office and a NSA 220 at the datacenter. they will handle the traffic between the two.  I will check with TW.

thanks again
Sure thing.
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I am still waiting to hear back from them. However, if it is possible, is it recommended or is there a better way to do it?

thanks again
Not sure what you mean.
As far as a point-to-point, you don't really need devices on either end - because the two ends are only connected to stuff that you control! Now, I'm sure you could nail up a VPN if you want between the two sites, but there's just not much reason - except to protect your two locations from Internet-based attacks or malicious traffic - coming from the far end of the point-to-point - that might impact your LANs.
Since it also sounds like you have two /24 networks, you *could* extend both locations to use the .25 network without a problem. 512 possible hosts is not too bad for a single segment from a broadcast chattiness perspective, as long as your switching is good at either location.
Just my opinion.


I meant is it better, or recommended, to segment into two IP networks and set up a new site Active Directory (already done as currently we have a VPN between the two), or is just one IP network acceptable, supported, best practice, etc.?

If I did go with one IP network for both the office and datacenter, how is DHCP and DNS affected? I already have a DC with DNS (it is a global catalog too) in the datacenter. I am putting our new exchange 2010 box as well as our terminal server at the datacenter as soon as our new storage comes in and is configured. one /24 network will fit us but since two are already configured, should we just leave as is?

This is what TW said:

The service is layer 2 to us and you can use layer 3 without issues. You do not need to segment the network if you do not want to do so.

Thanks again for your help
That extra info helps.
If you've already got everything in place, then leave it.
If you went with one network, you'd be changing a couple of things re DHCP/'d have one server for DHCP at one location or the other taking care of both locations. You'd have multiple DNS servers - maybe one at each location. You'd spend more time putting the networks together than it's worth. You've already got two segmented, well-designed LANs - who already talk successfully with each other! String up that point-to-point and leave the rest's a good thing.


OK. thanks for the help. last quick question:

currently our sonicwall is the DHCP server at the datacenter. should I move that to a windows DHCP server since we'll be putting our exchange and terminal servers there permanently?

thanks again

here is another question I just posted in case you have any insight into this issue
Re: DHCP - yeah, I'd flip that to your Windows box. It's a better plan long-term.

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