Private Line config trouble

  • 1
  • Question
  • Updated 1 month ago
  • Answered
I am trying to configure a Comcast layer 2 Ethernet Private Line between two sites and can't figure out what I'm doing wrong.  We have disparate subnets at the sites and use local DHCP servers, so extending the L2 is not an option.  

I have an ICX6450 on one side and an ICX7250 on the other side.  Both are running router code and I have reached my wits end on this. 

Any direction would be appreciated.   
Photo of Matthew

Matthew

  • 2 Posts
  • 0 Reply Likes

Posted 1 month ago

  • 1
Photo of Jon Maiman

Jon Maiman, Employee

  • 5 Posts
  • 3 Reply Likes
From your description you will need to set up routing between the two sites.   Specifically try doing the following:

1) Allocate a new Layer 3 IP Subnet for the Comcast L2 Ethernet Private Line.   For illustration purposes in this example, lets call it 10.255.255.0/24.

2) At site 1, put the IP address 10.255.255.1 on the port that connects to the Comcast CPE Box (E.g. Connection to the Comcast Layer 2 Ethernet Privae Line Service).  

3) At site 2, put the IP address 10.255.255.1 on the port that connects to the Comcast CPE Box (E.g. Connection to the Comcast Layer 2 Ethernet Privae Line Service).  

4) Next you will need define static routes to point to the subnets at the other site.

5) So for site 1, add a static route for each subnet at site 2 with a next hop of 10.255.255.1

6) Similarly for site 2, add  a static route for each subnet at site 1 with a next hop of 10.255.255.2

With the above you should now be able to route between the sites and all subnets should be reachable from either location.   

--Jon

P.S.  Rather than putting an IP Address directly on the physical interfaces that connect to Comcast you could create a L2 VLAN for it and then assign the IP addresses to VE"s associated with that L2 VLAN.   This would give you more flexibility in the future if you want to define more than one VLAN going across the Comcast  L2 Private Ethernet for different purposes.   
  
Photo of Matthew

Matthew

  • 2 Posts
  • 0 Reply Likes
Thanks Jon!

I am pinging across the EPL now, which is further than I have gotten yet.  What has me confused now is that our router is an ICX 7750 with no copper ports.  The switch I have the EPL plugged into is part of the access stack in our datacenter.  

Do I add a route on the 7750 for the site 2 subnets with the next hop of the access stack IP, and then put a route on the stack that points to the site 2 EPL IP?

Of course, during regular hours I can't test these route changes, but at least with your help on on the right track.

Thanks again!