So, Comcast EDI delivers two IP blocks.
/30 and /29
I programmed my WAN port with the /30 and I am able to get out to the internet. However, I want to setup to use the IPs in my /29.
AKA, so I have my LAN and I want to have all traffic come from an IP in my /29 and use the /30 as a default route. Let me know if I'm not being clear.
You'll either need to place a L3 device in front of the MX which can handle this type of setup, or ask Comcast to provide the /29 as the handoff and skip the /30. This is a limitation of the MX line. Our solution in the past was to put an MS320 in front of the MX and create two L3 interfaces on it - one with the /30 for the Comcast handoff, the second with the IP space Comcast was routing to us.
Thank you for the quick reply!
I have an MS225P, would this work if I used that in front and then routed back to the MX? And VLAN it off for those ports?
Yep, that should work since the MS225's support 16 static routes. Just make sure you create the /30 interface first so the default route is set properly.
Also keep in mind you'll still need to get the MS225 Internet access through a non-routed interface. So just plug it into your internal network in your usual management VLAN in addition to the Comcast interface and the MX interface.
Ok, so in theory I can still have my APs in this switch as well?
I would have the Comcast Ciena in the MS225, plug in the internet port the the MX to the MS Switch that has the /29 and then have the rest of the devices behind the firewall?
As long as you create the /30 interface on the switch first, it will correctly use that as the default route for all other L3 interfaces you create. You should still set the MX's gateway as the /29 block IP you assign to the MS225 though.