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 simply 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 Services), 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

Security is responsible to ensure regular auditing of this policy and automates such audits 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 network disconnection of systems by Security. System owners will have to demonstrate compliance before regaining complete network access. Repeat violators or active attempts to circumvent these policies will be reported to senior management at the NCSA, and could result in more severe prohibitions.

Exceptions Process

For any rule or policy, exceptions may be needed. Security will review requests for exceptions. Decisions will be made by Security after appropriate consultation with the NCSA IT Operations Board. Appeals to decisions can be made to the Director's Office.

Policy Maintenance

Security 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 created.

NCSA Network Zones

The following zones and their accompanying policies are described logically as specific addresses are subject to change.

High Performance Datacenter (HPDC) Zone

Definition:

This is the zone (formerly called "Zone 1") 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 as described in the Installation Subzone.
• An accepted vulnerability and patch management plan must be in place.
• Disable any unnecessary services and accounts, and enforce with host-based firewalls where possible.
  • Inform Security if the list of services changes.
• Enable host-based brute-force mitigations utilizing 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.
• Routing, traffic forwarding, bridging subnets and other forms of internetwork traffic proxy is prohibited without expressed permission from Security & Networking.
• Maintain and enforce a list of authorized administrators, and keep records up-to-date so that Security can quickly determine responsible parties for the system. At least one responsible party must be a full-time employee working at the NCSA.
• Provide Security with accounts on the system or a way to quickly get access 24/7 for emergencies.
• Notify Security of any sensitive, confidential or regulated data expected to be on the system.

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 network flows 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 for approved, secure remote access services.

Research & Internal Services Zone

Definition:

This zone includes Raised Access Floor (RAF) space in the NCSA building as well as a logical extrusion into NPCF for redundancy. Most of this space maps physically to the 3rd floor server room, 3003 NCSA.

Types of Systems:

This zone is for servers supporting R&D projects and internal services at NCSA. The ITS director determines which systems are placed in this zone based on space, power, cooling and usage considerations together with ADS and Security. Systems in this zone do not have the same 24/7 level of service, uptime requirements, network bandwidth and security services available to them as those in the HPDC zone.

Security Requirements:

Servers, whether supporting internal NCSA services or NCSA projects and their customers, are important, and their compromise can have a significant effect NCSA productivity and reputation. Whether or not they are even considered production servers, the impact can be significant if the data on the systems is exposed due to privacy considerations, regulatory & legal requirements, or confidentiality agreements. Therefore, certain accountability is required of all these systems.

Systems or their administrators must:

• Use two-factor authentication for administrative access or escalation, or request an exemption from Security.
• Disable routing, traffic forwarding, bridging between subnets and other forms of internetwork traffic proxy through the host unless approved by Security & Networking.
• Label systems in the rack and keep labels up-to-date.
• Maintain and provide the security team with:
  • accounts on the system or a way to quickly get access 24/7 for emergencies
  • purpose of the system and notification of any high risk or confidential data (as defined by UIUC policy).
  • a list of authorized administrators and a responsible full-time NCSA staff person
  • a list of necessary services/ports open
  • a plan for vulnerability and patch management

It is important that changes in the information initially provided to the security team are kept up-to-date, and system owners will need to update this annually. Changes to include high risk or confidential data need to be updated as soon as possible by contacting Security.

Systems or their administrators should:

• Enable host-based brute-force mitigations utilizing the security team's host-based IDS if possible.
• Forward system logs to the security team's log collector.
• Use the NCSA LDAP for authorization and an NCSA centralized authentication service.
• Use host-based firewalls to enforce list of services running.

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 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 policies that apply broadly to every host are campus and NCSA employee security policies and a requirement to register hosts using an NCSA ID before accessing the network.

Security Requirements:

Systems in this zone 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 if different from the NCSA ID, give a point-of-contact for Security.
  • 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 subnets without approval from Networking & Security.
• Business Office systems are administered and maintained by ITS, and the corresponding workstations and laptops are on a firewalled network.

Requirements for NCSA wireless networks:

The NCSA wireless networks (those giving public NCSA IP addresses) must not give an adversary advantages they wouldn't already have with NCSA authentication credentials and thus could execute from anywhere with VPN access. 

• Cryptographic and security configurations will be consistent with UIUC policies and standards of practice.
• NCSA wireless networks are not for guest use, but instead guests 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 or equivalently controlled to not allow servers for outside the NCSA IP space.

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 NIDS. 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, badge readers, iris scanners, 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 a single ACMS workstation that must connect with iCard systems elsewhere on campus.
  • This ACMS workstation can only be connected to via RDP from a single remote workstation run by Facilities & Services for troubleshooting and support.
• All other remote connections, even if temporary for support, must be approved by the Security Office. 

Isolated Zones

Definition:

Sometimes there is a need for a 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), 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 exiting and reentering the NCSA network.
  • Security can approve limited exceptions to whitelist direct access to key NCSA services, such as DNS, and these exceptions will be documented.
• Systems in an isolated zone are treated as external from a security perspective. As such, they may not benefit from any of the security services or monitoring normally provided.