Ports Used for HA

Firewalls configured as High Availability (HA) peers must be able to communicate with each other to maintain state information (HA1 control link) and synchronize data (HA2 data link). In Active/Active HA deployments the peer firewalls must also forward packets to the HA peer that owns the session. The HA3 link is a Layer 2 (MAC-in-MAC) link and it does not support Layer 3 addressing or encryption.
Destination Port
Protocol
Description
28769
28260
TCP
TCP
Used for the HA1 control link for clear text communication between the HA peer firewalls. The HA1 link is a Layer 3 link and requires an IP address.
28
TCP
Used for the HA1 control link for encrypted communication (SSH over TCP) between the HA peer firewalls.
28770
TCP
Listening port for HA1 backup links.
28771
TCP
Used for heartbeat backups. Palo Alto Networks recommends enabling heartbeat backup on the MGT interface if you use an in-band port for the HA1 or the HA1 backup links.
99
29281
IP
UDP
Used for the HA2 link to synchronize sessions, forwarding tables, IPSec security associations and ARP tables between firewalls in an HA pair. Data flow on the HA2 link is always unidirectional (except for the HA2 keep-alive); it flows from the active firewall (Active/Passive) or active-primary (Active/Active) to the passive firewall (Active/Passive) or active-secondary (Active/Active). The HA2 link is a Layer 2 link, and it uses ether type 0x7261 by default.
The HA data link can also be configured to use either IP (protocol number 99) or UDP (port 29281) as the transport, and thereby allow the HA data link to span subnets.

Related Documentation