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Cisco Bug: CSCuj56186 - N7K: PBR next-hop is wrongly installed into TCAM

Last Modified

Nov 27, 2020

Products (7)

  • CiscoPro Workgroup EtherSwitch Software
  • Cisco Nexus 7000 10-Slot Switch
  • Cisco Nexus 7000 4-Slot Switch
  • Cisco Nexus 7000 18-Slot Switch
  • Cisco Nexus 7700 18-Slot Switch
  • Cisco Nexus 7000 9-Slot Switch
  • Cisco Nexus 7700 10-Slot Switch

Known Affected Releases

6.1(2)E5 6.2(2)

Description (partial)

PBR next-hop is wrongly installed into TCAM if NX-OS tries to push PBR into TCAM before adjacency is resolved. As a result, the traffic is not forwarded properly.

Nexus7009# show hardware access-list input entries detail

  [00ae:0064:0064] redirect(0x5b)-routed ip   [34]       <<<< redirect to adj_index 0x5b

Nexus7009# show hardware access-list input entries detail VLAN 2012  :

  [00ad:0063:0063] redirect(0x1)-routed ip   [0]        <<<< redirect to adj_index 0x1

The adj_index could be other than 0x1.

This issue happens if all PBR related I/Fs are configured on the same F2 card.

Pushing PBR into TCAM befor adjacency is resolved can happen with the following sequence.

// BASE //
vlan 2010,2012

interface Ethernet6/5
  switchport mode trunk
  switchport trunk allowed vlan none
  no shutdown

// Sequence //
`feature pbr`
`interface Vlan2010`
`no shutdown`
`ip address`
`ip policy route-map PBR-Pool`
`interface Vlan2012`
`no shutdown`
`ip address`
`ip policy route-map PBR-PoolURL`
`int e6/5`
`switchport trunk allowed vlan 2010,2012`

It also happens with module reload.
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