Users Guide

Scalable Site-to-Site VPN Tunnels
ArubaOS 6.4.4.0 and later supports site-to-site IPSEC tunnels based on a Fully Qualified Domain Name (FQDN).
When you identify the remote peer for a branch config group using an FQDN, that config group can be applied
across multiple branch controllers, as the configured FQDN can resolve to different IP addresses for each local
branch, based on local DNS settings.
In ArubaOS 6.4.4.0 and later releases, crypto maps for site-to-site VPNs support a VLAN ID as the identifier for
the source network. When the VPN settings are pushed to branch controller, the IKE negotiation process uses
the IP address range for the VLAN. This feature allows you to push the same source network configuration to
multiple branch controllers, as each branch controller negotiates a different source source network IP for its
VLAN based on the IP pool for that local branch.
Layer-3 Redundancy for Branch Controller Masters
ArubaOS 6.4.4.0 introduces support for a redundant secondary master controller in branch controller
deployments. This prevents a scenario where a master controller acts as a single point of failure if the link to
the master goes down, or a co-located Master-Standby VRRP controller pair fail due to a network failure or local
natural disaster.
Configuring Layer-3 Redundancy
The IPaddress of a primary master and a secondary, backup master controller can be defined for a branch
during the Zero-touch provisioning process, and is either defined in a DHCP server, or is manually entered into
the branch controller during the initial startup dialog. The primary and secondary master controllers must be
manually kept in synchronization by ensuring all the configuration, certificates, and branch controller whitelist,
AP whitelist and local user database are the same in both of them.
Database settings are not automatically synchronized from a primary master to a secondary master with Layer-3
redundancy. All database settings, certificates, whitelist settings and profile configurations must be kept in sync
manually.
Viewing Controller Connectivity Status
The status of the branch's connection to a primary and secondary master controller appears in the
WAN
dashboard page of the branch controller WebUI. To display the current status of the branch controller's
connectivity to the master and secondary master IP addresses, click the Layer3 Redundancy tab on the
Status section of the dashboard.
Figure 37 Branch Controller Redundancy Status
Failover Behaviors
When a provisioned branch controller detects that its primary master is unreachable, it attempts to reconnect
to the primary master for the time period defined by the
Master L3 Redundancy Switchover Timeout in its
branch controller configuration. If the branch controller cannot reconnect to the primary master controller
during this switchover timeout period, and the secondary controller is up and reachable, the branch controller
Dell Networking W-Series ArubaOS 6.5.x | User Guide BranchController Config for Controllers | 209