ISP frames through CSS326?

SwOS
1

Hi,

In my building, the fiber optic arrives in a room far away from my server rack. The ISP has provided me with an ONT that translate fiber to Ethernet. Then I use standard ethernet cable to arrive in the server rack where my router is. In the same rack, I have a Mikrotik CSS326 that switch all my LAN ethernet.

If I connect directly the ONT to the router, I have internet fine (PPPoE over VLAN), but if I try to go through the CSS326, I can’t get internet on my router (can’t connect to WAN).

Fiber-ONT-Ethernet-Router : OK

Fiber-ONT-Etehnet-CSS326-Router : KO

On the CSS, I have:

  • enabled “System→DHCP & PPPoE Snooping→Trusted Ports” for the relevant ports (note that “Add Information Option” box is enabled)

  • configured the VLANs for the relevant ports (and the ISP VLAN ID is not used in the LAN)

What am I missing?

2

I am not very familiar with swOS (I use only CRS switches and ROS) but I remember I have done same thing using customer-bought 2x CSS318 - without any snooping, just pure VLAN.

Make sure that you don’t have any VLAN interface on PPPoE VLAN - maybe ISP is limiting MAC address count on ont port and if there are more than 1 than it may not work - check that on your ISP VLAN in CSS 326 and simply ask ISP what they see on ONT port at your site