[c-nsp] ebgp load balancing using maxiumu-paths TCAM impact onSup720-3BXL?

[Kevin Loch]

I am doing 8 parallel full tables to the same provider on an rsp720
with no issues.  You can barely do 6 full tables on a sup720-3bxl.
The limitation is processor memory not tcam.

Here is what 6 looks like with 12.2SXF16:

                 Head    Total(b)     Used(b)     Free(b)   Lowest(b) 
Largest(b)
Processor   44B0D4B0   927902544   815304080   112598464    88132216 
77785200


              FIB TCAM usage:                     Total        Used 
   %Used
                   72 bits (IPv4, MPLS, EoM)     524288      281823 
     54%

As you can see memory is very tight with 6 parallel full tables
but tcam usage is normal. I would not expect any problems with 2
however.

- Kevin

Brad Hedlund (brhedlun) wrote:
> Better to use 'ebgp multihop' and peer to provider router's loopback.  
> Then have equal cost static routes to provider's loopback via the two 
> physical interface next hop IP addresses.
> 
> Cheers,
> 
> Brad Hedlund
> bhedlund at cisco.com
> http://www.internetworkexpert.org
> 
> 
> On May 20, 2009, at 9:47 PM, "Peter Kranz" <pkranz at unwiredltd.com> wrote:
> 
>> Setup is as follows; 2 edge routers, each with a BGP session receiving 
>> full
>> routes to the same provider router. The provider is load balancing 
>> inbound
>> traffic to our AS nicely, 50/50 between the edge routers.. I would 
>> also like
>> to load balance the outbound traffic.. I've considered adding 
>> 'maximum-paths
>> 2' to install the two equal paths, but an concerned about FIB TCAM 
>> impacts.
>> Will adding this command cause each equal cost route to take one 
>> additional
>> TCAM entry, i.e. full routing table x 2 > 524k TCAM limit = EPIC 
>> meltdown?
>>
>>
>>
>> Current FIB TCAM:
>>
>> L3 Forwarding Resources
>>
>>             FIB TCAM usage:                     Total        Used
>> %Used
>>
>>                  72 bits (IPv4, MPLS, EoM)     524288      285506
>> 54%
>>
>>                 144 bits (IP mcast, IPv6)      262144           5
>> 1%
>>
>>
>>
>> Peter Kranz
>> <http://www.UnwiredLtd.com> www.UnwiredLtd.com
>> Desk: 510-868-1614 x100
>>
>> Mobile: 510-207-0000
>> <mailto:pkranz at unwiredltd.com> pkranz at unwiredltd.com
>>
>>
>>
>> _______________________________________________
>> cisco-nsp mailing list  cisco-nsp at 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 at puck.nether.net
> https://puck.nether.net/mailman/listinfo/cisco-nsp
> archive at http://puck.nether.net/pipermail/cisco-nsp/