Introduction

NCSA logically divides its network into several different trust zones. Traffic between these zones is monitored by a Network Intrusion Detection System (NIDS), but traffic within a single zone may not be visible to the NIDS. Therefore, systems within a single zone must be trusted and hence hardened to a similar level.

These zones can vary significantly in how they are trusted: from networks trusted little more than the general Internet to networks that require stringent vetting and auditing. Most networks are public, but some are very isolated and not even routed. The common requirements across all zones are only that systems follow University security policies and that the Security and Networking teams can quickly identify the location and responsible party for all hosts on our networks.

Governance

Policy Application

For the purposes of this document, production systems are defined as any system, to include allocated systems, intended to provide reliable computational and/or data services to a networked constituency. These systems include not only “customer facing” hosts, such as web servers, file servers, login nodes, etc., but also the infrastructure required to support these systems, such as backend database servers, backup and storage systems, authentication servers, etc.

NCSA IT Operations Board

The leaders of ADS (Advanced Digital Services), ITS (Information Technology Systems), and Security are responsible for application of this policy. These three groups are the service providers of infrastructure at NCSA and meet regularly to discuss security issues and strategy for providing better services.

Audit

The Security Team is responsible to ensure regular auditing of this policy and automates auditing where possible. However, responsible does not always mean executing every audit on their own. This is a group endeavor among all the NCSA service providers and requires coordination and cooperation between ADS, ITS and Security.

Violation

Violations of this policy may result in immediate disconnection of systems by the security team, especially in critical and sensitive zones. Failure to obtain prior approval for installations based on zone policies or attempts to circumvent these policies will be reported to senior management at the NCSA.

Exceptions Process

For any rule or policy, exceptions may be needed. The Security Office will review requests for exceptions. Decisions will be made by the Security Office after appropriate consultation with ADS and ITS leadership. Appeals to decisions can be made to the Director's Office.

Policy Maintenance

The Security Office will review this policy annually with the leadership of ADS and ITS to see if changes are needed. It will also be updated as needed for new network environments that are needed.

NCSA Network Zones

The following zones and their accompanied policies are described logically as specific subnets are subject to change.

High Performance Datacenter (HPDC) Zone

Definition:

This is the zone for production systems in the data center and consists of most machines in 2020 NPCF. It includes both public and private networks.

Types of Systems:

Systems requiring high availability, physical security and high performance networking are hosted here. This includes not just supercomputers, but core storage, security, networking equipment, and more. These systems are first built in a firewalled subzone until fully vetted by the security team, which is responsible for regular auditing of systems against the security requirements below.

Security Requirements:

• Until vetted, these machines are firewalled to only accept connections from NCSA hosts or to port 22 (SSH).
• A vulnerability and patch management plan must be in place.
• Disable any unnecessary service and accounts, and enforce with host-based firewalls where possible.
  • Inform the security team if the list of services changes.
• Utilize the security team's host-based IDS if possible.
• Forward system logs to the security team's log collector.
• Utilize non-local accounts for remote access unless otherwise approved.
• Require two-factor bastions, jump-hosts or VPNs for access to administrative interfaces.
• Disable IP-forwarding and do not bridge networks without approval from Security & Networking.
• Maintain and enforce an up-to-date list of authorized administrators, and keep records up-to-date so that the security team can quickly determine responsible parties for the system. At least one responsible party must be a full-time employee working at the NCSA.
• Provide the security team with accounts on the system or a way to quickly get access 24/7 for emergencies.

Monitoring:

All external links in and out of this zone are monitored by the NIDS. New hosts that appear on this network but have not been vetted may be automatically or manually blocked at the border gateway until investigated and vetted. Network traffic entirely within this zone is unmonitored by the NIDS, but netflows are collected.

Installation Subzone

While new systems are being built and configured in this zone and before they are fully vetted by security, they are firewalled in a subzone.

Security Requirements:

These systems must:

• Use secure, non-default passwords.
• Be protected by a stateful, network firewall that only accepts connections from non-NCSA hosts on port 22.

NCSA Office & Wireless Zone

Definition:

This zone includes all of the office and wireless networks that assign NCSA IP addresses. This includes offices in the NCSA building, NPCF and at least one wireless network, but does not include most Raised Access Floor (RAF) space.

Types of Systems:

This zone supports a variety of systems including desktops, laptops, portable devices and research systems. This zone is the most flexible and has the fewest security controls. While firewalled subnets are encouraged by default, the only policies that apply broadly to every host are campus and NCSA employee security policies and the requirement to register hosts using an NCSA ID before accessing the network.

Security Requirements:

Systems in this network must:

• Follow all campus and NCSA employee policies regarding software updating, virus scanning, data security, incident reporting, etc.
• Register with an NCSA ID to receive an IP address and give a point-of-contact for Security as part of the process.
  • The default network type is firewalled, though users can opt-out
  • Network registration is only for NCSA staff and should not be done for guests. Guest accounts and temporary registrations are available for these use cases.
  • Reregistration is required annually.
• Do not bridge networks without approval from Networking & Security.
• Business Office systems are administered and maintained by ITS, and the corresponding workstations and laptops on a firewalled subnet.

Requirements for NCSA wireless networks:

The NCSA wireless networks (those giving public NCSA IP addresses) must not give an adversary without NCSA authentication credentials an advantage over simply attacking from the Internet. 

• Enterprise WPA2 wireless protection will be used.
• NCSA wireless networks are not for guest use, but instead should use a CITES provided wireless network.
• These networks authenticate and authorize against the NCSA LDAP service. 
• Only the NCSA and/or CITES network teams can configure access points and networking hardware for the wireless network -- there will be no rogue or unapproved wireless networks.
• The security team must have the ability to quickly map wireless IPs and timestamps to users for at least 90 days.
• Like the default office subnets, the primary wireless network is firewalled at the NCSA border.

VPN Zone

Definition

NCSA offers a VPN services with different authentication profiles. These can be used as more flexible bastions in conjunction with firewall rules, to access privately addressed subnets, or to reach other services that might be blocked at the border (e.g., mounting filesystems).

Security Requirements

Systems connected to the NCSA VPN are monitored unencrypted on the internal side of the VPN with the network IDS. Authentication to the VPN requires the use of valid and authorized NCSA credentials.

Physical Security Zone

Definition:

This is an isolated zone only for the NPCF physical security systems.

Types of Systems:

All NPCF physical security systems, and only those systems, are part of this zone.  This includes the camera DVRs, the badge readers, the iris scanners, the ACMS workstations (for badging, control and enrollment), and the ACMS database server.

Security Requirements:

• Devices on this network can neither connect to the other networks or be connected to except for an ACMS workstation that must connect with iCard systems elsewhere on campus.
• The ACMS workstation can only be connected to via RDP from a single remote workstation run by Facilities & Services for troubleshooting and support.
• All other connections, even if temporary for support, must be approved by the Security Office. 

Island Zones

Definition:

Sometimes there is a need for special subnet that is treated no differently than an external network and does not route internally with NCSA systems. This could be because the systems on the subnet would not meet the requirements of this policy (e.g., they bring their own unmonitored WAN links or cannot be hardened sufficiently), that it is actually an external network extruding into our physical infrastructure, or that external requirements or regulations require extra isolation.

Security Requirements:

• Connections to other NCSA hosts would not be allowed unless existing and entering again.
  • Limited exceptions whitelist access direct access to key NCSA services, such as DNS, can be approved by the Security Office and documented as an exception.
• Systems in an island zone are treated as external from a security perspective. They may not benefit from any of the security services or monitoring normally provided.