350-601: Implementing and Operating Cisco Data Center Core TechnologiesDemo

Strict Unicast RPF mode on Cisco NX-OS is enabled per interface with the command "ip verify unicast source reachable-via rx", which verifies that the source address of an incoming packet is reachable via the same interface (rx) on which the packet arrived, per the FIB entry. This differs from loose mode, which uses "reachable-via any" and only checks that the source is reachable via any interface. Configuring the Ethernet1/1 interface with the IP address and the "ip verify unicast source reachable-via rx" statement therefore implements strict uRPF for IPv4 traffic on that interface, as described in the Cisco Nexus 9000 Series NX-OS Security Configuration Guide's section on Configuring Unicast RPF.