NOTE: The NLR part of the core network was shut down when NLR ceased operations, but is still documented for historical reasons on some wiki pages.

The current GENI network core is a set of OpenFlow-capable switches in Internet2.

There are currently three standing backbone interconnect VLANs (3715, 3716, and 3717) carried on the five switches in the core, which are located in the five cities shown on the maps below. Two of the VLANs are topologically a broken ring (to help prevent accidental loops). The third VLAN (3717) is a ring. The gap in each of the broken-ring VLANs is between two different links, to provide either a longer or shorter path through the core between two switches. The three VLANs are not interconnected in the core, and should not extend beyond the backbone providers into regionals or campuses.

VLAN 3715

VLAN 3716

VLAN 3717

Testing / monitoring

 The core network status page at BBN shows whether a test host at BBN can ping the other test hosts right now.

Backbone Integration

Click the picture below for the full-sized image.

Note: Network Diagrams maintained by GMOC, historical revisions can be found here -

VLAN Translation

The shared mesoscale VLAN in the core uses loopback cables for VLAN translation where needed. Some of those VLANs are not experimenter controlled, but rather are used for isolated transport to a specific site. On the Internet2 core switches, the  Layer1Transport software is used to pass that traffic along at layer 1, similar to how a psuedowire would work.