Configure the following commands on the Huawei firewall:[USG] interface G0/0/1[USG] ip urpf loose allow-defult-route acl...

For loose inspection: if the source address of the packet exists in the FB of the firewall: the packet passes the inspection directly

For the case where the default route is configured, but the parameter allow-defult-route is not configured. As long as the source address of the packet is in the FIB table of the firewall

If it does not exist, the message will be rejected.

For the situation where the default route is configured and the parameter allow-defult-route is matched at the same time, if the source address of the packet is in the FIB table of the firewall

If the packet does not exist in the loose check mode, all packets will pass the URPF check and be forwarded normally.

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For the configuration of the default route, and at the same time matching the parameter allow-defult-route, if the source address of the message is in the FIB table of the firewall

If it does not exist in the l0e check, the packet cannot pass the URPF check.