[c-nsp] maximum dCEF routes on GSR engine 2 cards

John van Oppen john at vanoppen.com
Sun Jul 29 05:48:21 EDT 2007


Yep, that is what I thought.   With that last command it looks like MPLS
could be the culprit, any advice to that end would be welcome.  In any
case, here are the details (I never knew about that last command):

cr1 #show ip cef sum
IP Distributed CEF with switching (Table Version 411705), flags=0x0
  222833 routes, 0 reresolve, 0 unresolved (0 old, 0 new), peak 222497
  410597 instant recursive resolutions, 0 used background process
  0 load sharing elements, 0 references
  0 in-place/0 aborted modifications
  37906144 bytes allocated to the FIB table data structures
  universal per-destination load sharing algorithm, id BA6A1595
  2(0) CEF resets
  Resolution Timer: Exponential (currently 1s, peak 1s)
  Tree summary:
   16-4-4-4-4 stride pattern
   short mask protection disabled
   222833 leaves, 58284 nodes using 11165764 bytes
  Transient memory used: 199036, max: 24248008

  Table epoch: 0 (222833 entries at this epoch)

Hardware resource allocation status summary
Green (Normal), Yellow (Caution) Red (Alarm)
Slot HW Resource Name        Util     Alert
2    E2_Rx_PLU                29        G
2    E2_Rx_TLU                99        R
3    E2_Rx_PLU                29        G
3    E2_Rx_TLU                100       R

Adjacency Table has 154 adjacencies
  138 IPv4 adjacencies
  16 IPv6 adjacencies


cr1 #show ip route sum
IP routing table name is Default-IP-Routing-Table(0)
Route Source    Networks    Subnets     Overhead    Memory (bytes)
connected       3           21          1680        3648
static          2           6           512         1216
ospf 1          0           1           64          152
  Intra-area: 0 Inter-area: 0 External-1: 0 External-2: 1
  NSSA External-1: 0 NSSA External-2: 0
bgp XXXXX       125146      97444       14245760    33844900
  External: 222565 Internal: 25 Local: 0
internal        2134                                2501048
Total           127285      97472       14248016    36350964
cr1-sea#


cr1#exec slot 3 show contr psa mem
========= Line Card (Slot 3) =========

Total Memory
------------
PLU SDRAM: 67108864 bytes
TLU SDRAM: 67108864 bytes
PSA SSRAM:  1048576 bytes

Free Memory     (Free Memory excluding chunks)
-----------
PLU SDRAM: 47534592 bytes       (47458304 bytes)
TLU SDRAM:  2742112 bytes       (  641152 bytes)
PSA SSRAM:   737152 bytes       (  726272 bytes)

Allocated Memory        (Allocated Memory including chunks)
----------------
PLU SDRAM:
Mtrie                         13225984 bytes    (13238272 bytes)
Tag lookup table               4244480 bytes    ( 4308480 bytes)
Frame switching table                0 bytes
ACL tables                           0 bytes
Load balancing table           2097152 bytes
FRoM Imposition table                0 bytes
PHoM imposition table                0 bytes

TLU SDRAM:
Adjacency table                  22208 bytes    (  161600 bytes)
LB Adjacency table                   0 bytes    (  161280 bytes)
LB Adjacency count                   0
Loadsharing information              0 bytes    (  172800 bytes)
Multicast hardware mstates           0 bytes
Mtrie prefix                      3264 bytes    (  164544 bytes)
Mtrie prefix 128 ACL          13023936 bytes    (13224960 bytes)
Mtrie prefix 448 ACL                 0 bytes    (       0 bytes)
Tag rewrite structures        51150816 bytes    (52577280 bytes)
Tag loadbalance structures           0 bytes    (  172800 bytes)
Frame switching                      0 bytes    (       0 bytes)
Frame switching (policing)           0 bytes    (       0 bytes)
FRoM imposition                      0 bytes    (       0 bytes)
PHoM imposition                      0 bytes    (       0 bytes)
ACL tables                           0 bytes

SSRAM:
Tag loadbalance structures         128 bytes    (   11008 bytes)
Loadbalance structures           21760 bytes    (   32640 bytes)
ACL usage                        20480 bytes
Other                           269056 bytes    (  279936 bytes)
  VPN usage                        128 bytes
  BGP PA usage                   65536 bytes
  CoS Transparency usage           128 bytes
  PIRC usage                       512 bytes
  SRC MAC Acct usage              6144 bytes
  VLAN usage                    196608 bytes

Largest Free Block
------------------
PLU SDRAM: 16251904 bytes
TLU SDRAM:   161280 bytes
PSA SSRAM:   726272 bytes



-----Original Message-----
From: Oliver Boehmer (oboehmer) [mailto:oboehmer at cisco.com] 
Sent: Sunday, July 29, 2007 1:00 AM
To: John van Oppen; cisco-nsp at puck.nether.net
Subject: RE: [c-nsp] maximum dCEF routes on GSR engine 2 cards

John,

number of prefixes for an Engine2 linecard depends on the features used
(VRFs, ACLs) and the way CEF allocates their memory (for example number
of loadinfos when you do any form of multipath). 
Can you show a "show ip route sum", "show ip cef summ" as well as an
"execute-on slot 3 show contr psa mem"? 
You can also check the Release-notes of CSCdt34374 for some info.

Engine0 don't have any dedicated forwarding memory, so Engine0 prefix
capacity is limited by LC DRAM only.

With the growth of the Internet routing table, E2 fowarding capactiy can
reach its limits depending on ACLs configured on the box.   

	oli


John van Oppen <> wrote on Sunday, July 29, 2007 8:10 AM:

> I am running into a problem where I am running out of dCEF resources
> on a couple of engine 2 line cards (both of the suspect cards are
> three port gigE cards) in my 12008s.   Anyone have hints on getting
> this usage under control or at least some actual numbers on what the
> actual maximum routing table size in the hardware forwarding table
> (since the E2_RX_TLU indicator seems to indicate forwarding entries).
> 
> Interestingly this is not affecting the engine 0 line cards in the
> routers, and I was wondering if anyone else with a full view of the
> routing table was having this happen?   It seems on my side to just
> have started one day and immediately have gone from a yellow alarm to
> 100% utilization, so it seems to me like something could be wonky.
> 
> 
> router>show ip cef re
> 
> Hardware resource allocation status summary
> 
> Green (Normal), Yellow (Caution) Red (Alarm)
> 
> Slot HW Resource Name        Util     Alert
> 
> 2    E2_Rx_PLU                29        G
> 
> 2    E2_Rx_TLU                100       R
> 
> 3    E2_Rx_PLU                29        G
> 
> 3    E2_Rx_TLU                100       R
> 
> 
> 
> 
> 
> Both cards are the following:
> 
> 
> 
> router#show cef line 3
> 
> CEF linecard slot 3, status up, fibhwidb sync, fibidb sync, adj sync
> 
>  Sequence number 20688, Maximum sequence number expected 21193, Seq
> Epoch 2
> 
>  Send failed 0, Out Of Sequence 0, drops 0
> 
>  Linecard CEF reset 2, reloaded 2
> 
>  2091179 elements packed in 32971 messages(72011038 bytes) sent
> 
>  32 elements cleared
> 
>  0/0/0 xdr elements in LowQ/MediumQ/HighQ
> 
>  247773/34/286 peak elements on LowQ/MediumQ/HighQ
> 
>  Keepalive timer will expire in 00:05:59
> 
>  Init window timer is not running
> 
>  Input  packets 1904878439, bytes 1322133076937
> 
>  Output packets 1631996819, bytes 1062121911533, drops 0
> 
>  UTI input packets 0, bytes 0
> 
>  UTI output packets 0, bytes 0
> 
>  0 proc sw, 0 proc sw fail, 0 hdr error
> 
> 
> 
>  CEF Table statistics:
> 
>  Table name                Version Prefix-xdr Status
> 
>  Default                    404607     702947 Active, sync, table-up
> 
> 
> 
> 
> 
> router#show diag 3
> 
> 
> 
> SLOT 3  (RP/LC 3 ): 3 Port Gigabit Ethernet
> 
>   MAIN: type 68,  800-6376-05 rev B0
> 
>         Deviation: 0
> 
>         HW config: 0x00    SW key: 00-00-00
> 
>   PCA:  73-4775-07 rev C0 ver 2
> 
>         Design Release 2.0  S/N SAD09100D9E
> 
>   MBUS: Embedded Agent
> 
>         Test hist: 0x00    RMA#: 00-00-00    RMA hist: 0x00
> 
>   DIAG: Test count: 0x00000000    Test results: 0x00000000
> 
>   FRU:  Linecard/Module: 3GE-GBIC-SC=
> 
>         Processor Memory: MEM-GRP/LC-256=
> 
>         Packet Memory: MEM-LC1-PKT-256=
> 
>   L3 Engine: 2 - Backbone OC48 (2.5 Gbps)
> 
>   MBUS Agent Software version 1.100 (RAM) (ROM version is 2.41)
> 
>   ROM Monitor version 16.12
> 
>   Fabric Downloader version used n/a (ROM version is 10.1)
> 
>   Primary clock is CSC 1
> 
>   Board is analyzed
> 
>   Board State is Line Card Enabled (IOS  RUN )
> 
>   Insertion time: 15w2d (1d09h ago)
> 
>   Processor Memory size: 268435456 bytes
> 
>   TX Packet Memory size: 134217728 bytes, Packet Memory pagesize: 8192
> bytes
> 
>   RX Packet Memory size: 134217728 bytes, Packet Memory pagesize: 8192
> bytes
> 
>   0 crashes since restart
> 
> 
> 
> 
> 
> Any ideas on optimization would be appreciated.
> 
> 
> 
> John
> 
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