H3C S5830V2 Security Configuration Manual page 243

Proceeds to step 2 for other packets.
2. uRPF checks whether the source address matches a FIB entry:
If yes, proceeds to step 3.
If not, proceeds to step 6.
3. uRPF checks whether the check mode is loose:
If yes, proceeds to step 8.
If not, uRPF checks whether the matching route is a direct route: if yes, proceeds to step 5. If not,
proceeds to step 4.
4. uRPF checks whether the receiving interface matches the output interface of a matching FIB entry:
If yes, proceeds to step 8.
If not, proceeds to step 9.
5. uRPF checks whether the source IP address matches an ARP entry:
If yes, proceeds to step 8.
If not, proceeds to step 9.
6. uRPF checks whether the FIB table has a default route:
If yes, proceeds to step 7.
If not, proceeds to step 9.
7. uRPF checks whether the check mode is loose:
If yes, proceeds to step 8.
If not, uRPF checks whether the output interface of the default route matches the receiving
interface of the packet: if yes, proceeds to step 8. If not, proceeds to step 9.
8. The packet passes the check and is forwarded.
9. The packet is discarded.
NOTE:
uRPF does not check multicast packets.
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