[c-nsp] Troubleshooting IPv6 throughput on a GSR 12410

[Aaron Daubman]

Thanks for the tip... where would I find documentation regarding IPv6
being CPU forwarded on engine 4 cards?  Is there a recommended GigE
card that would support "advanced features" ('flexible' QoS, MPLS...)
and also hardware-forward v6 traffic at line-rate?

Also, overall CPU util shows up high (see below) but how do I
correlate that to CPU-switched v6?  (eg, are there other show commands
that would point to that being the issue, or would one have to know
that Engine4 handles v6 like that?)

> > The generated flow hits my GSR on a port on a Modular Gbe Line card:
>
> This may be your problem. I recall the modular cards as being engine 4
> which means CPU forwarded IPv6. The CPU in question is the Linecard CPU.
> Can you check the LC CPUs.

Here's the LC output (CPU util is high...)
----------------------------------------------------------
LC-Slot2#sh proc cpu sorted 1min
CPU utilization for five seconds: 52%/51%; one minute: 53%; five minutes: 52%
  PID Runtime(ms)   Invoked      uSecs   5Sec   1Min   5Min TTY Process
  54      559348    663562        842  0.47%  0.47%  0.46%   0 LC COS STAT
  59       48036    201072        238  0.15%  0.16%  0.15%   0 OC192 QoS Mgr
  68        1280    409094          3  0.00%  0.10%  0.06%   0 Line Card Virtua
  29       90620    903124        100  0.07%  0.03%  0.01%   0 FIA192 Poll
  26       10908    110922         98  0.00%  0.02%  0.01%   0 Per-Second Jobs
   5       34620     10235       3382  0.00%  0.02%  0.00%   0 Check heaps
  38       15796      1681       9396  0.00%  0.02%  0.00%   0 Per-minute Jobs
  72       17076      7122       2397  0.00%  0.01%  0.00%   0 CEF Scanner
  70         280       452        619  0.00%  0.00%  0.00%   0 Exec
  10           0         2          0  0.00%  0.00%  0.00%   0 LC ATM OAM Input
  11           0         2          0  0.00%  0.00%  0.00%   0 LC ATM OAM TIMER
  12           0      1680          0  0.00%  0.00%  0.00%   0 IPC Dynamic Cach
  13           0         2          0  0.00%  0.00%  0.00%   0 MFIB LC Process
  14          12    100738          0  0.00%  0.00%  0.00%   0 IPC Periodic Tim
  15           0         9          0  0.00%  0.00%  0.00%   0 IPC Seat Manager
  16           8    100740          0  0.00%  0.00%  0.00%   0 IPC Deferred Por
  17           0         1          0  0.00%  0.00%  0.00%   0 MBUS Flash
  18          28    108367          0  0.00%  0.00%  0.00%   0 MBUS Background
   9           0         2          0  0.00%  0.00%  0.00%   0 LC ATM Common Pr
  20           0         2          0  0.00%  0.00%  0.00%   0 SMART
  21           0         1          0  0.00%  0.00%  0.00%   0 SERIAL A'detect

LC-Slot2#sh hardware
Cisco Internetwork Operating System Software
IOS (tm) GS Software (GLC1-LC-M), Version 12.0(31)S2, RELEASE SOFTWARE (fc1)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2005 by cisco Systems, Inc.
Compiled Fri 14-Oct-05 23:43 by pwade
Image text-base: 0x4001109C, data-base: 0x41400000

ROM: System Bootstrap, Version 12.0(20050624:151124)
[lming-CSCei07200-V31 1.14dev(0.1)] DEVELOPMENT SOFTWARE
ROM: GS Software (GLC1-LC-M), Version 12.0(31)S2, RELEASE SOFTWARE (fc1)

  LC-Slot2 uptime is 1 day, 4 hours, 0 minutes
System restarted at 04:46:09 EST Wed Dec 14 2005
Running default software

cisco E4P-GEFE (R7000) processor (revision 0x02) with 524289K bytes of memory.
R7000 CPU at 350Mhz, Implementation 39, Rev 3.3, 256KB L2 Cache
Last reset from power-on
4 GigabitEthernet/IEEE 802.3 interface(s)

Configuration register is 0x0
--------------------------------------------------------------------------

Thanks again,
     ~Aaron