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Cisco Bug: CSCvs30042 - Nexus 93180YC-FX does not encapsulate traffic destined to Tunnel interface (GRE)

Last Modified

Jan 13, 2020

Products (52)

  • Cisco Nexus 9000 Series Switches
  • Cisco Nexus 3548-X Switch
  • Cisco Nexus 9516 Switch
  • Cisco Nexus 3548 Switch
  • Cisco Nexus 9396PX Switch
  • Cisco Nexus 31108TC-V Switch
  • Cisco Nexus 3548-XL Switch
  • Cisco Nexus 93108TC-FX Switch
  • Cisco Nexus 92160YC-X Switch
  • Cisco Nexus 3064 Switch
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Known Affected Releases

7.0(3)I7(7)

Description (partial)

Symptom:
++ Using GREv6/IPv4 or GREv4/IPv4, tunnel encapsulation is failing to occur on specifically the Nexus 93180YC-FX
++ On the Nexus 93180YC-EX, we are seeing proper encapsulation occurring using the same configuration
++ When looking at the 'show hardware internal tah l3 tunnel' output, the encapsulation looks proper
N9K-1# slot 1 quoted "show hardware internal tah l3 tunnel"


| Tunnel Lif | Encap Type | No.of Adj | Outer Bd |     Src Ip      |    Src Mac      |     Dest Ip     |     Dest Mac    |    VRF   |       sip       |       dip       |
|   RPF BD   |            |           |          |                 |                 |                 |                 |          |                 |                 |
|------------|------------|-----------|----------|-----------------|-----------------|-----------------|-----------------|----------|-----------------|-----------------|
   0x1004         v4_greip        1           6          0.0.0.0         00:00:00:00:00:00       10.111.252.192 f8:0b:cb:e5:d9:fb      1  10.111.252.193     10.111.252.192

*** dstinfo 8192 rwencap 1 rwdmac 1 rwipprofile 0
*** srctep 0x204300 mytep 0xffff0000 ecmp_id 2 num_inact 0
ecmp_id 2: num_ecmp_mems 1 hw_index 0
  flags 0x0 bd 6 dst_idx 177 egress_intf 1
  vlan 4095 tunnel_id 0x1800000 l3_bd 4147
  DMAC: f8:0b:cb:e5:d9:fb  SMAC: 00:3a:9c:08:60:07


++ When looking up the dstinfo index in the DstInfoTable, there is not an entry on the -FX switch

module-1# debug hardware internal sug dump asic 0 slice 0 table tah_sug_luc_dstinfotable 8192 c f
Initting block addresses

asic instance is 0
asic slice is 0
tbl name is tah_sug_luc_dstinfotable
start entry is 8192
change entries only
one field per line
Block base address: 0x03400000
1st table entry address: 0x03620000
module-1#

++ The packet is getting dropped within rwx due to the outer_vlan_mbr_drop, which can be seen when running a Python script to count the dropped packets

>>> tahoe.stats.rwx_drop(0)
<< Snippet >>
outer_vlan_mbr : 0x00000005 <=================== After running command with 5 failed pings, we see this set to 5
<< Snippet >>

Conditions:
++ This is non-functional on 7.0(3)I7(3-7.0(3)I7(7)
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