Comcast WAN/LAN Blocks

Product Discussion Peplink Balance
1

Good day,

We need help with configuring our Peplink with comcast directly. I can get the WAN interface working(WAN Block) but I cannot access the LAN block. Here is a forum post with a similar problem from years ago. Peplink | Pepwave - Forum

Right now we use Momentum telcom for our VOIP. They put in an Edgemarc router. Service comes into the Comcast device, goes into the Edgemarc(configured with the P2P/WAN block) and then into the peplink, which is configured with a LAN block IP. We will be switching to another telcom and eliminating the edgemarc, which would have us go from the comcast device to the peplink directly. I was able to test this and assigned the peplink interface with the WAN block usable IP given from Comcast. I have internet access but I cannot access the LAN block side from the outside(we have services like VPN that utilize them). Comcast said there needs to be routing in place on the peplink for this to work and that is where I am falling short. Below is our Comcast fiber circuit info.

P2P/WAN IP scope: 50.236.146.36/30
Gateway IP: 50.236.146.37
Usable IP: 50.236.146.38
LAN IP scope: 50.236.146.48/28
Gateway IP: 50.236.146.49
Usable range: 50.236.146.50 – 50.236.146.62

Here is what Comcast engineer said to do: “You’ll need to configure the P2P/WAN IP to your WAN interface. But you will also set up the routes for your LAN block through the router.”

2

So you just want to make the 50.236.146.48/28 network routable behind the Peplink LAN?

  1. Configure a WAN on the Peplink with the 50.236.146.38/30 IP.

  2. On the WAN configuration disable NAT and enable IP forwarding (hidden behind the blue question mark where the NAT button is).

  3. Configure the LAN or a new VLAN interface on the Peplink with 50.236.146.49/28.

That should be all that is required, if you have a more involved setup where you have other networks behind the Peplink you might need to do some outbound NAT mappings so their traffic is NAT’d out the WAN interface correctly.

There should not be any need to add routes, I would hope that Comcast are configured to route the LAN side /28 via that .37 IP and assuming your Peplink has only 1 WAN interface you would essentially have a default route to send everything via that.

3

Thank you very much. For #3, are you talking about another physical interface and cable or a config? Where are those settings? I will add we have another WAN(Fios) coming into the peplink too, already in drop in mode. we have a watchguard sitting behind the peplink too. Thank again.

4

Are you talking about here?

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pep2.png

5

I couldn’t get it to work. I configured as advised in step 1. Peplink was able to connect to the internet. I disabled NAT and enabled IP forwarding. I configured a new LAN but could not get it to save if i used .48 or .49/28. It said it couls not be the ip address. I was able to save it with one of the other usable IPs in the range, like .55. Unfortunately I still wasnt able to reach services associated with the LAN block IPs.