OSPF routes in Software ?

Answered Question
Jul 27th, 2011

Hi All,

I have a stack of 2 3750G with enhanced software running as my OSPF routers to our duel WAN lines (both used simultaneously, both same size)

Since yesterday I have changed 2 parts of the config

the SDM is now the Routing Dual IP V4 & 6

and system Jumbo MTU size is now 9000 bytes

since then I also see the CPU loading go up by 400%

I reckon this is because of the SDM change....chck this out

Table: IPv4:Default (id 0)

sources:               Default table

ref count:             2073

flags (0x00):          none

smp allowed:           yes

default network:       0.0.0.0/0

route count:           1958                                                       <<<<1958 current routes

route count (fwd):     1958

route count (non-fwd): 0

Database epoch:        3 (1958 entries at this epoch)

Subblocks:

  These rates are ndbs/minute.

   RIB update rate:           1

   RIB update peak rate:      319

Table: IPv6:Default (id 0)

sources:               Default table

ref count:             4

flags (0x00):          none

smp allowed:           no

default network:       none

route count:           2

route count (fwd):     2

route count (non-fwd): 0

Database epoch:        2 (2 entries at this epoch)

Subblocks:

  These rates are ndbs/minute.

   RIB update rate:           0

   RIB update peak rate:      0

The current template is "desktop IPv4 and IPv6 routing" template.

The selected template optimizes the resources in

the switch to support this level of features for

8 routed interfaces and 1024 VLANs.

  number of unicast mac addresses:                  1.5K

  number of IPv4 IGMP groups + multicast routes:    1K

  number of IPv4 unicast routes:                    2.75K

    number of directly-connected IPv4 hosts:        1.5K

    number of indirect IPv4 routes:                 1.25K                                   <<<< only 1.25k can be "hardware" routed ?

  number of IPv6 multicast groups:                  1.125k

  number of directly-connected IPv6 addresses:      1.5K

  number of indirect IPv6 unicast routes:           1.25K

  number of IPv4 policy based routing aces:         0.25K

  number of IPv4/MAC qos aces:                      0.5K

  number of IPv4/MAC security aces:                 0.5K

  number of IPv6 policy based routing aces:         0.25K

  number of IPv6 qos aces:                          0.625k

  number of IPv6 security aces:                     0.5K

and this is the old SDM I used

"desktop routing" template:

The selected template optimizes the resources in

the switch to support this level of features for

8 routed interfaces and 1024 VLANs.

  number of unicast mac addresses:                  3K

  number of IPv4 IGMP groups + multicast routes:    1K

  number of IPv4 unicast routes:                    11K

    number of directly-connected IPv4 hosts:        3K

    number of indirect IPv4 routes:                 8K                                        <<<<8k routes - a little different

  number of IPv4 policy based routing aces:         0.5K

  number of IPv4/MAC qos aces:                      0.5K

  number of IPv4/MAC security aces:                 1K

now the biggie.....is this my problem why my network has slowed down ?

and can I change an SDM manually or can I just use the templates ?

Cheers for help in advance......

Fraser

I have this problem too.
0 votes
Correct Answer by MarkC.Williams_2 about 2 years 9 months ago

what is the output of 'show platform tcam utilization'?

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CiscoIsInYou Wed, 07/27/2011 - 21:25

Hi Fraser,

As far as the SDM templates are concerned, using the dual stack templates results in less hardware capacity allowed for each resource. Do not use them if you plan to forward only IPv4 traffic.

• Routing—The routing template maximizes system resources for unicast routing, typically required for a router or aggregator in the center of a network.

• VLANs—The VLAN template disables routing and supports the maximum number of unicast MAC addresses. It would typically be selected for a Layer 2 switch.

• Default—The default template gives balance to all functions.

• Access—The access template maximizes system resources for access control lists (ACLs) to accommodate a large number of ACLs.

Approximate features allowed by each template

Approximate features allowed by Dual-IPv4-IPv6 Templates are as follows-


So if you want to -

1- Maximize routing capablities use "sdm prefer routing"

2- Revert to default use "sdm prefer default" which balances all features.

HTH.

Mark Answered if this resolves & also Rate if helpful.

Thanks

Shaz

Fraser Reid Wed, 07/27/2011 - 23:19

Thanks Mark and CiscoIsInYou for both your answers.

I Need IPV6 for a few Server2008R2 Features.

But I had to change back to the standard IPV4 Routing SDM yesterday as the Software routing was making the RTD go from 3ms to 150 ms on specific subnets - not good.

Now I reckon the only way forward is to buy 2 C-3925's to perform IPV4 and IPV6 OSPF simultaneously as the WAN lines are both 40Mbit and may be lowered in speed in the future (yes - no increase!) so bigger routers I will not need.

Cisco - please make it so that the SDM templates can be changed.......will there ever be an IPV6 Only sdm ? That would work for me....

simon.dwyer Thu, 07/28/2011 - 04:12

Why do you want a IPv6 only SDM? you are still running IPv4.  Or are you talking down the track?

I am sure cisco will do a SDM ipv6 only down the track

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Posted July 27, 2011 at 12:25 AM
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Tags: sdm, ospf, mtu, routing, tcam, table
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