[prev in list] [next in list] [prev in thread] [next in thread] 

List:       cisco-nsp
Subject:    Re: [c-nsp] Cisco Nexus 3k Route Selection\Packet Forwarding Debugging
From:       Mike Hammett via cisco-nsp <cisco-nsp () puck ! nether ! net>
Date:       2023-05-02 15:02:57
Message-ID: 1624826460.71553.1683039777983.JavaMail.zimbra () ics-il ! net
[Download RAW message or body]

We have upgraded NX-OS to a new major version and have the same results.



Apr 20 09:36:05 UTC: %UFDM-3-FIB_IPv4_ROUTE_CONSISTENCY_CHECKER_FAIL: FIB IPv4 \
consistency checker FAILED on slot 1 Apr 19 13:55:57 UTC: \
%IPFIB-2-FIB_TCAM_RESOURCE_EXHAUSTION_LPM_IPV4: FIB TCAM exhausted for IPV4 routes in \
LPM table 

show forwarding inconsistency
...
69. slot(1), vrf(default), prefix(198.XXX.XXX.0/YY), Route inconsistent in FIB \
Software.


Well, those seem like problems.


EASTGATE401-BGP-02# show ip route summary
IP Route Table for VRF "default"
Total number of routes: 292
Total number of paths:  292

Unicast paths:
Best paths per protocol:      Backup paths per protocol:
  am             : 48           None
  local          : 8
  direct         : 8
  static         : 5
  broadcast      : 19
  bgp-XXXXX      : 204

Number of routes per mask-length:
  /0 : 1       /8 : 1       /18: 2       /19: 4       /20: 26
  /21: 24      /22: 35      /23: 18      /24: 100     /27: 1
  /28: 1       /29: 1       /30: 4       /32: 74




It's choking on only 292 routes?


Error Message FIB_TCAM_RESOURCE_EXHAUSTION_LPM_IPV4: FIB TCAM exhausted for IPV4 \
routes in LPM table Explanation The TCAM device in the Layer 3 forwarding ASIC has \
reached its system limits for IPv4 entries in the LPM table.

Recommended Action No action is required.



TCAM is exhausted and no action is recommended?


Error Message UFDM-3-FIB_IPv4_ROUTE_CONSISTENCY_CHECKER_FAIL: FIB IPv4 consistency \
checker FAILED on slot [chars] Explanation FIB Ipv4 route consistency checker Failed. \
Route database is consistent with hardware

Recommended Action No action is required.


The FIB is inconsistent and no action is recommended?


EASTGATE401-BGP-02# show system internal forwarding route summary

slot  1
=======


IPv4 hosts & routes summary on module 1
---------------------------------------------

Max host route entries : 8192
Total number of IPv4 host routes used: 72
Max LPM table entries : 7167
Total number of IPv4 LPM routes used : 16



I seem to be out of my depth here in that 292 is less than 7167, but yet it still \
fails.




----- 
Mike Hammett 
[ http://www.ics-il.com/ | Intelligent Computing Solutions ] 
[ https://www.facebook.com/ICSIL ] [ \
https://plus.google.com/+IntelligentComputingSolutionsDeKalb ] [ \
https://www.linkedin.com/company/intelligent-computing-solutions ] [ \
https://twitter.com/ICSIL ]  [ http://www.midwest-ix.com/ | Midwest Internet Exchange \
]  [ https://www.facebook.com/mdwestix ] [ \
https://www.linkedin.com/company/midwest-internet-exchange ] [ \
https://twitter.com/mdwestix ]  [ http://www.thebrotherswisp.com/ | The Brothers WISP \
]  [ https://www.facebook.com/thebrotherswisp ] [ \
https://www.youtube.com/channel/UCXSdfxQv7SpoRQYNyLwntZg ]

----- Original Message -----
From: "Mike Hammett via cisco-nsp" <cisco-nsp@puck.nether.net>
To: "Cisco Network Service Providers" <cisco-nsp@puck.nether.net>
Sent: Monday, April 3, 2023 12:16:52 AM
Subject: [c-nsp] Cisco Nexus 3k Route Selection\Packet Forwarding Debugging

We have a Nexus 3064 that is setup with partial BGP tables and is routing based on \
that. 


I've done a show ip bgp for an IP of interest and it has an expected next hop IP. I \
show ip arp on that next hop IP and it has the expected interface. 


However, sFlows show the packets leaving on a different interface, the one that would \
carry the default route for routes not otherwise known. 


If the next hop IP is expected and the ARP of that next hop IP is expected, why are \
packets leaving out an unexpected interface? 




----- 
Mike Hammett 
Intelligent Computing Solutions 

Midwest Internet Exchange 

The Brothers WISP 

_______________________________________________
cisco-nsp mailing list  cisco-nsp@puck.nether.net
https://puck.nether.net/mailman/listinfo/cisco-nsp
archive at http://puck.nether.net/pipermail/cisco-nsp/
_______________________________________________
cisco-nsp mailing list  cisco-nsp@puck.nether.net
https://puck.nether.net/mailman/listinfo/cisco-nsp
archive at http://puck.nether.net/pipermail/cisco-nsp/


[prev in list] [next in list] [prev in thread] [next in thread]