ECMP is supported on all Palo Alto Networks firewall
models, with hardware forwarding support on the PA-7000 Series,
PA-5200 Series, and PA-3200 Series. VM-Series firewalls support
ECMP through software only. Performance is affected for sessions
that cannot be hardware offloaded.
ECMP is supported on Layer 3, Layer 3 subinterface, VLAN, tunnel,
and Aggregated Ethernet interfaces.
ECMP can be configured for static routes and any of the dynamic
routing protocols the firewall supports.
ECMP affects the route table capacity because the capacity is
based on the number of paths, so an ECMP route with four paths will
consume four entries of route table capacity. ECMP implementation
might slightly decrease the route table capacity because more memory
is being used by session-based tags to map traffic flows to particular
Virtual router-to-virtual router routing using static routes
does not support ECMP.