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Cisco Bug: CSCua87100 - Incorrect u-RPF flag set after next-hop change.

Last Modified

Feb 16, 2017

Products (4)

  • Cisco Nexus 7000 Series Switches
  • Cisco Nexus 7000 10-Slot Switch
  • Cisco Nexus 7000 18-Slot Switch
  • Cisco Nexus 7000 9-Slot Switch

Known Affected Releases


Description (partial)


Traffic to u-RPF enabled prefix getting dropped even after the RPF failure condition is is cleared.


U-RPF check on on prefix fails if the next-hop is reachable via null 0 and fall back to existing valid next-hop.Found in senario where BGP based Real Time Black-hole Routing
inject a prefix reachable via next-hop that is routed to null0 to administratively drop traffic to certain segments.
Once the drop condition is removed , ie the RPF falls back to the previous state (valid - reachable via rx) , traffic remains blocked.
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Bug Details Include

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