H3C Technologies H3C S12500-X Series Switches - Manual (Page 248)

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2. uRPF checks whether the source address matches a FIB entry:
{
If yes, proceeds to step 3.
{
If no, proceeds to step 6.
3. uRPF checks whether the check mode is loose:
{
If yes, proceeds to step 8.
{
If no, uRPF checks whether the matching route is a direct route:
− If yes, proceeds to step 5.
− If no, proceeds to step 4.
4. uRPF checks whether the receiving interface matches the output interface of the matching FIB entry:
{
If yes, proceeds to step 8.
{
If no, proceeds to step 9.
5. uRPF checks whether the source IP address matches an ARP entry:
{
If yes, proceeds to step 8.
{
If no, proceeds to step 9.
6. uRPF checks whether the FIB table has a default route:
{
If yes, proceeds to step 7.
{
If no, proceeds to step 9.
7. uRPF checks whether the check mode is loose:
{
If yes, proceeds to step 8.
{
If no, uRPF checks whether the output interface of the default route matches the receiving
interface of the packet:
− If yes, proceeds to 8
− If no, proceeds to 9.
8. The packet passes the check and is forwarded.
9. The packet is discarded.
NOTE:
uRPF does not check multicast packets.