And in Palo Alto terms, it's Active/Passive (same as Active/Standby in Cisco terms). This is from the 4.1.9 manual. Active/Passive HA ...

So here we go. This is the Palo Alto configuration that works: Interface 1/6 is physically connected to port 2/1/26 on my Brocade stack. Route table. This is the configuration that doesn't work: ...