Implementing CyberArk CorePAS in Multi-Domain Environments

Implementing CyberArk CorePAS across multiple Active Directory domains, network segments and geographic sites adds complexity that you’ll need to plan around up front. Below is a deep-dive into the main issues you’re likely to hit, plus practical approaches to work through each “gotcha.”

1. Domain Trusts and Authentication

Challenge: CorePAS needs to resolve users and groups in each domain you integrate. Without the right trusts in place, you’ll get authentication failures, account lookup errors and orphaned sessions.

• One-way vs two-way trusts
  • If Domain A trusts Domain B but not vice versa, users from B can authenticate against A’s PVWA, but admins in A cannot see B’s accounts. Two-way trusts simplify group-based authorisations and reporting.
• Forest-level considerations
  • In multi-forest environments you might prefer LDAP binding to each domain rather than relying on global catalog lookups. This reduces dependence on upstream trusts but adds configuration work.
• UPN suffixes
  • Ensure each domain’s User Principal Name suffix is routable and unique. If two domains share the same suffix (eg. corp.local vs dev.local both using @corp.local), PVWA may pick up the wrong account.

Work-around:

1. Map each domain explicitly in PVWA’s Active Directory configuration, pointing at a dedicated LDAP server or Global Catalog.
2. For untrusted or high-security domains, use a one-way trust and configure CyberArk to bind with a service account in that domain for read access only.

2. DNS and Network Segmentation

Challenge: CorePAS components (Vault, CPM, PSM, PVWA) need name resolution and connectivity across each site. Firewalls and split-DNS can cause unexpected timeouts or certificate mismatches.

• Split-DNS pitfalls
  • If your internal DNS view for “vault.corp.local” differs in each site, components may register against the wrong IP. That can break cluster clustering or cause a CPM node to miss its peers.
• Firewall rules
  • PSM needs to reach target servers on RDP/SSH ports, but also talk back to the Vault on 1858/1859. Ensure both inbound and outbound rules permit those flows in all network zones.
• Latency and packet loss
  • High-latency WAN links will slow automated password rotations and session brokering. Excessive retries can trigger failover or put load on your vault cluster.

Work-around:

1. Use Forward Lookup Zones in each DNS server that mirror the CorePAS hostnames and IPs per site.
2. Establish dedicated network paths (eg. VPN tunnels or MPLS circuits) with QoS rules to prioritise PAM traffic.
3. Where latency is an issue, deploy local CPM and PSM services in each site as “remote site connectors” back to the central vault.

3. Multi-Site Vault Clustering

Challenge: Building a single highly available vault across multiple data centres can introduce split-brain risk, replication conflicts or clock drift issues.

• Replication topology
  • Active-active clustering across three sites is tempting but hard to keep in sync. Instead, consider a hub-and-spoke: central pair of Vault nodes in your primary site, with read-only replicas in DR or branch offices.
• Clock synchronisation
  • If vault nodes differ by more than 2 seconds, certificate-based replication and auditing can fail. Each site must use the same NTP servers or a stratum-1 source.
• Failover timing
  • In a disaster scenario, automatic failover may not complete cleanly if the secondary site thinks the primary is still alive.

Work-around:

1. Define a “site priority” in your vault cluster settings so that only the second site’s nodes ever become active in a DR event.
2. Schedule regular simulated failover drills to validate replication consistency and avoid surprises when you really need to switch over.

4. Safe Design and Access Models

Challenge: With multiple domains, you may be tempted to grant cross-domain admin rights or cram all accounts into one giant safe. That undermines principle of least privilege and makes auditing noisy.

• Safe-per-domain vs safe-per-application
  • Grouping accounts by domain can simplify assignments but hides application context. Conversely, a safe per application may span domains (eg. web farm across two forests), which complicates permissions.
• Inherited permissions
  • CyberArk supports nested safe-groups, but nested permissions resolved across domains may not behave as expected if trusts change or a domain goes offline.

Work-around:

1. Adopt a hybrid pattern: create a top-level safe for each application and then domain-specific sub-safes under it. Use AD groups named by domain and application (eg. BRS-WebAppA-Admins) to drive permissions.
2. Keep a clear naming convention and document every safe’s scope in your ISMS or runbook.

5. PSM and Jump-Host Provisioning

Challenge: Protecting RDP/SSH across multiple networks often leads to carve-outs in firewalls or deploying jump hosts in each zone. Ensuring users always connect through PSM can become a management headache.

• Jump-host proliferation
  • If you deploy a jump host in every network, patching and hardening becomes laborious. Missing one can leave a back door.
• Credential caching
  • Some PSM methods cache credentials locally on the jump host – if that host is compromised, attackers may gain a window of access.

Work-around:

1. Use the “Broker-only” PSM model where the PSM acts purely as a proxy, and no credentials are stored on the jump host.
2. Automate patching and configuration of your PSM nodes via your existing configuration management platform to guarantee consistency.

6. Operational and Support Model

Challenge: Operating multiple domains/sites increases your support overhead – more certificates to rotate, more monitoring points, more backup jobs.

• Certificate expiry
  • You’ll have SSL/TLS certs for PVWA, CPM, KVMA (Key Management), plus your vault master-key certificates in HSMs if used. Missing one expiry can take down authentication for dozens of domains.
• Backup consistency
  • Each site’s CPM may queue password changes for local accounts. If you only backup your central vault, you’ll lose these queues in a DR event.

Work-around:

1. Centralise certificate management – use a PKI that supports certificate templates and auto-enrolment to push renewed certs to all CorePAS components at once.
2. Backup your CPM and PSM nodes’ local queues (in addition to the vault DB) and store those backups alongside your vault snapshots.

7. Governance and Change Control

Challenge: When you have multiple domains and sites, even small policy changes (eg. rotating service-account passwords every 30 days) can cascade a flood of change requests and support tickets.

• Approval complexity
  • Which business owner in which domain signs off on a password-rotation policy change?
• Change windows
  • Different sites may have different maintenance windows or blackout periods (eg. retail sites open 24/7).

Work-around:

1. Implement a tiered governance model: central policy board that defines global guardrails, plus domain-level stewards authorised to tweak local settings within those guardrails.
2. Automate the creation of change requests in your ITSM tool when a global policy update is scheduled so that each domain’s change board has visibility.

Conclusion and Next Steps

Running CorePAS across multiple domains, networks and sites is far from trivial—but with careful upfront planning you can avoid the classic traps: trust misconfigurations, DNS anomalies, split-brain clusters and support overload. Start by mapping your domain topology, network zones and application footprint. Then use the patterns above to design your safe hierarchy, replication topology and PSM placement. Finally, bake your monitoring, backup and governance processes into your standard operating workflows so you keep control as you scale.

If you’d like a template for multi-forest PVWA configuration or a sample network diagram showing CPM-to-vault connectivity per site, let me know and I can share it. Good luck!