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New Member

Cisco Router support for load balance

i need to know how many links i can using with load-balance on the same router ?

i have router cisco 2901 , 3 providers , every provider having 4 links

can i load balance between 12 links ?

i am using static route

2 ACCEPTED SOLUTIONS

Accepted Solutions

Cisco Router support for load balance

exactly it is not about it can be done rather it is better way to be done

using PBR with IPSLA and load share the traffic based on source and/or destination will be an option to load share the traffic among the links

per packet load balancing is not always recommended over two links so over 12 will be a big issue for voice and out of order tcp as well

hope this help

Super Bronze

Cisco Router support for load balance

Disclaimer

The    Author of this posting offers the information contained within this    posting without consideration and with the reader's understanding that    there's no implied or expressed suitability or fitness for any  purpose.   Information provided is for informational purposes only and  should not   be construed as rendering professional advice of any kind.  Usage of  this  posting's information is solely at reader's own risk.

Liability Disclaimer

In    no event shall Author be liable for any damages whatsoever  (including,   without limitation, damages for loss of use, data or  profit) arising  out  of the use or inability to use the posting's  information even if  Author  has been advised of the possibility of such  damage.

Posting

If your images supports OER/PfR, it would be the best option for load balancing (actually it can optimize for end-to-end).

11 REPLIES

Cisco Router support for load balance

Ok, so let me get this straight, YOu have a Cisco 2901 and 3 different ISPs, and each provider has 4 links

to the router? so this would be a total of 12 links on this one router?

From your Cisco 2901, how does it connect to each service provider? Also, what network range has been provided to

you from the server provider(s)?

New Member

Cisco Router support for load balance

it does connect to the service providers through Serial ports (HWIC4t).

for the network range , every link having differnt network serial to serial /32 . for lan i will using GRE tunnels 

Cisco Router support for load balance

Ok, so I'm a little confused here. How many serial ports is your Cisco 2901 communicating with to the ISPs? Are there, three HWIC4Ts, providing full capacity to each service provider, or just a HWIC4T with on link to three seperate serial ports on the HWIC4T?

Also, when you're talking about load-balancing do you mean LBng internall or out on the service providers network?

Super Bronze

Cisco Router support for load balance

Disclaimer

The    Author of this posting offers the information contained within this    posting without consideration and with the reader's understanding that    there's no implied or expressed suitability or fitness for any  purpose.   Information provided is for informational purposes only and  should not   be construed as rendering professional advice of any kind.  Usage of  this  posting's information is solely at reader's own risk.

Liability Disclaimer

In    no event shall Author be liable for any damages whatsoever  (including,   without limitation, damages for loss of use, data or  profit) arising  out  of the use or inability to use the posting's  information even if  Author  has been advised of the possibility of such  damage.

Posting

I'm not 100% sure about statics.  Older IOS images has a default of 4 equal cost routes in a routing protocol which, I recall, could be reconfigured to support up to 6.  Later IOS images, I believe, support many more equal cost routes (32?, 64?) but default, I also believe, is still 4.

What do you see in your route table when you have 12 statics defined to the same destination subnet via different links?

Cisco Router support for load balance

Yeah, I wasn't sure about that either Joseph. I know from most Cisco documentation or Cisco Press I should say, it has 4 as the default for equal-cost load-balancing. I was pretty sure you could go higher in newer IOS verisons, I just don't know the exact number.

Cisco Router support for load balance

i am not sure if the 2901 is the right option for your case using 12 links !!!

how much bandwidth each link has ? how big is the routing table and route being processed with regard to the memory and cpu you have

also if you consider using PBR with some IP sla to lowdshare the traffic selectvly it might be good idea as well using the concpet in the bellow link

https://supportforums.cisco.com/docs/DOC-8313

hope this help

if helpful Rate

New Member

Cisco Router support for load balance

Dear Marean

thank you for your help

every link is 2M , the routing table is not big and i think is no issue for CPU and RAM

i just to confirm if i do 12 static route with same metric it willbe working fine with load-balance per-packets ?

Purple

Cisco Router support for load balance

Hi,

the max is 16 so it should work with 12 but is it the best way to achieve your goal ?

Regards.

Alain

Don't forget to rate helpful posts.

Cisco Router support for load balance

exactly it is not about it can be done rather it is better way to be done

using PBR with IPSLA and load share the traffic based on source and/or destination will be an option to load share the traffic among the links

per packet load balancing is not always recommended over two links so over 12 will be a big issue for voice and out of order tcp as well

hope this help

Super Bronze

Cisco Router support for load balance

Disclaimer

The    Author of this posting offers the information contained within this    posting without consideration and with the reader's understanding that    there's no implied or expressed suitability or fitness for any  purpose.   Information provided is for informational purposes only and  should not   be construed as rendering professional advice of any kind.  Usage of  this  posting's information is solely at reader's own risk.

Liability Disclaimer

In    no event shall Author be liable for any damages whatsoever  (including,   without limitation, damages for loss of use, data or  profit) arising  out  of the use or inability to use the posting's  information even if  Author  has been advised of the possibility of such  damage.

Posting

If your images supports OER/PfR, it would be the best option for load balancing (actually it can optimize for end-to-end).

New Member

Cisco Router support for load balance

thank you all for your help

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