Skip Navigation


  Welcome to HORNET. HORNET is the Johns Hopkins Research Network. HORNET is designed to be the collaborative network platform for the Maryland Advanced Research Computing Center (MARCC).


MARCC Center and HORNET Network Overview


MARCC - Maryland Advanced Research Computing Center

The Maryland Advanced Research Computing Center is a Top 10 US University HPC center, shared and jointly managed by Johns Hopkins University and the University of Maryland College Park while being available to researchers across the state. MARCC manages high performance computing, highly reliable data storage, and provides collaborative scientific support to empower computational research, scholarship, and innovation.

HORNET - Johns Hopkins Research Network

The Johns Hopkins Research Network is the high-speed, collaborative network platform for MARCC. At the center of the HORNET architecture is a 100-Gigabit full mesh core. Research systems can take full advantage of the MARCC research facility and efficiently collaborate with other John Hopkins teams through their ability to connect to HORNET at speeds of 10-Gigabit and higher. High speed connectivity is not limited to Johns Hopkins as HORNET also provides 100-Gigabit, Internet2 connectivity to other remote research institutions through the use of Globus Data Transfer Nodes. Researchers can take advantage of the Data Transfer Node services offered through MARCC, or they can set up their own systems.


HORNET Network Topology



Physical Topology

The HORNET switching core is a full mesh, 100-Gigabit link network configured on three Cisco Nexus 7700 series switches. The Nexus 7700 switches serve as distribution points for all Nexus 2000 and Nexus 3000 access layer switches. One Nexus 7700 core switch is installed on each of the following campuses:

  • Maryland Advanced Research Computing Center (MARCC) – Bayview HPC Facilities.
  • University – Homewood Campus.
  • Clinical – East Baltimore Hospital Campus.

Logical Topology

HORNET is logically divided into three network domain zones.

   Domain 1: Internal Research Network – Blue Zone

      The Blue Zone is HORNET’s primary network. All servers, compute nodes, and other network connected research systems will connect to this network. This network provides connectivity for all research systems between the three campus sites, connectivity to the compute and storage resources at MARCC, and the Data Transfer Nodes.

   Domain 2: Internal Research Network – Green Zone

      The Green Zone is a restricted access domain for special-purpose systems that need to be publically accessible. A login node is an example of a special-purpose host. Host systems within this zone will receive a public IP address within a designated public IP subnet range.

   Domain 3: Science DMZ network – Black Zone.

      The Black Zone is set aside for dedicated Data Transfer Nodes only. Data Transfer Nodes move data between  the Internal and Science DMZ networks, and they allow for high speed WAN data transfers to other remote research network systems over the Internet2 network.

Connecting to HORNET

Several Cisco Nexus switch options are available. Standard configurations can be modified to support your specific connectivity needs. Unit price includes the cost of the device, maintenance, and support.

Cisco Nexus 2000 Fabric Extender (FEX)

Nexus 2000 series FEX solution offers 1-Gig and 10-Gig, copper and fiber Ethernet connectivity. It supports high-speed, low latency, north-south network traffic flows.

Cisco Nexus 3000 Switches

Nexus 3000 switches offer higher performance 1-Gig, 10-Gig, and 40-Gig+, copper and fiber Ethernet connectivity. They provide line-rate traffic throughput on all ports. They also provide ultra-low east-west, port-to-port latency and support high-speed, low latency, north-south network traffic flows.

Joining HORNET

If you would like to join HORNET or would like more information about the network, please send your inquiries to:

Please contact Jaime Combariza for more information on Maryland Advanced Research Computing Center, Bayview High Performance Computing Facility.

   Jaime Combariza
   Director of MARCC, Department of Chemistry Associate Research Scientist