[c-nsp] SUP720 TFIB scan not completing

[Rodney Dunn]

You can try a 'sh ip cef events' and see if you see a /32 adjacency
entry constantly changing. That will cause us to run the TFIB scanner
which piggybacks on the CEF scanner.

We improved this with:

CSCsb16512
Externally found moderate defect: Resolved (R)
High CPU in CEF Process and CEF scanner due to prefix reresolve

There have been other TFIB scan not completing bugs but this is one
I remebered due to the high CPU it caused.

You can correlate 'sh ip cef events' to a debug mpls lfib cef
and try to figure out if a mac is constantly changing on one of the
mpls enabled interfaces.

Rodney


On Tue, Jan 24, 2006 at 11:13:56PM +0100, Christian Bering wrote:
> Hi all,
> 
> Earlier today we started seeing the following messages on a SUP720 in
> our network:
> 
> Jan 24 22:45:24.014 MET: %TFIB-SP-7-SCANSABORTED: TFIB scan not
> completing.  MAC string updated.
> -Traceback= 40C32E2C 40C331AC 40C09FE0 40C0A580 40BF06D8 40BF0AF0
> 40BF0DCC 40BF19C8
> Jan 24 22:45:49.522 MET: %TFIB-7-SCANSABORTED: TFIB scan not completing.
> MAC string updated.
> -Traceback= 41EB455C 41EB48DC 405233CC 405240F0 40699230 406998BC
> 4069A4E0 4008AB54
> 
> CPU utilization was at 100%:
> 
> #show proc cpu | ex 0.00
> CPU utilization for five seconds: 99%/1%; one minute: 99%; five minutes:
> 99%
>  PID Runtime(ms)   Invoked      uSecs   5Sec   1Min   5Min TTY Process
>    5      177464     31490       5635  4.10%  0.94%  1.01%   0 Check
> heaps
>    8       29148    143305        203  0.07%  0.03%  0.04%   0 ARP Input
>   26        7128      5161       1381  0.07%  0.06%  0.07%   0 HC
> Counter Timer
>  115     2187696    284021       7702 91.24% 88.63% 88.40%   0 CEF
> Scanner
>  118       40632    431972         94  0.07%  0.06%  0.05%   0 IP Input
>  154       48560     24386       1991  0.07%  0.22%  0.17%   0 IP RIB
> Update
>  167        4596     22184        207  0.07%  0.02%  0.01%   0 CEF
> process
>  288       19060    563793         33  0.07%  0.07%  0.07%   0 Standby
> (HSRP)
>  292        6024     58523        102  0.07%  0.05%  0.06%   0 ISIS Adj
>  296        4304     47582         90  0.07%  0.06%  0.05%   0 ISIS Upd
>  309      403040    173895       2317  1.62%  3.23%  2.99%   0 BGP
> Router
> 
> Clearing route tables etc. did nothing. I finally rebooted the router
> and then it ran fine for about 4 hours. However, right after this router
> came back up, a neighbouring router started exhibiting the same
> behaviour. The two rouers are connected via both L2 and L3 links and are
> now both acting this way. I am puzzled.
> 
> Sofware version is. 12.2(18)SXE3
> 
> What should I look for?
> 
> Thanks,
> Christian
> 
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