Per packet load sharing on 7600

[connect101]

Dear all,

Does everyone has an idea on how to activate "per-packet load sharing" on a 7606S with RSP720-3CXL engine and 7600-ES+20G3CXL module.

The IOS version is : 7600rsp72043_rp-ADVIPSERVICESK9-M), Version 12.2(33)SRD4, RELEASE SOFTWARE (fc2)

I tried the two (2) following commands but they are not supported :

- hw-module slot1 ip load-sharing per-packet

- ip load-sharing per-packet (on interface)

Any help is welcome.

Thanks in advance.

[Atif Awan · Accepted solution]

connect101 wrote:
Dear all,
Does everyone has an idea on how to activate "per-packet load sharing" on a 7606S with RSP720-3CXL engine and 7600-ES+20G3CXL module.
The IOS version is : 7600rsp72043_rp-ADVIPSERVICESK9-M), Version 12.2(33)SRD4, RELEASE SOFTWARE (fc2)
I tried the two (2) following commands but they are not supported :
- hw-module slot1 ip load-sharing per-packet
- ip load-sharing per-packet (on interface)
Any help is welcome.
Thanks in advance.

7600 does not support per packet load balancing no matter what hardware you have installed on it.

Atif

[connect101]

Hi Atif,

Thanks for you reply. It's really damage as we need absolutely to perform a per-packet load sharing on our 7606S routers as a part of an MPLS-TE.

We have four (4) inequal bandwidth links and need to forward paket with ratios.

Thanks.

[Atif Awan]

connect101 wrote:
Hi Atif,
Thanks for you reply. It's really damage as we need absolutely to perform a per-packet load sharing on our 7606S routers as a part of an MPLS-TE.
We have four (4) inequal bandwidth links and need to forward paket with ratios.
Thanks.

I am not sure how per packet load balancing would help you with unequal bandwidth links. If you are using MPLS-TE then you can look at unequal cost load sharing with TE. Based on your statement the TE approach sounds closer to what you are trying to achieve. Do a command lookup for the "tunnel mpls traffic-eng load-share" command on the 'Command Lookup' tool and it will provide you with configuration sample of how to configure this.

Atif

[connect101]

Atif,

This what we are using now. But we tried on a 7300 lab, and the load-share was achieved by using per-packet load-balancing.

Using per-destination method does not allow to have a different trafic volume forwarding on the interfaces.

But we will try again on the 7606S and will keep informed.

[Atif Awan]

connect101 wrote:
Atif,
This what we are using now. But we tried on a 7300 lab, and the load-share was achieved by using per-packet load-balancing.
Using per-destination method does not allow to have a different trafic volume forwarding on the interfaces.
But we will try again on the 7606S and will keep informed.

Just want to reiterate that per packet load sharing and per destination load sharing are primarily applied to situations where you have equal cost paths. If you have multiple unequal costs paths then most IGPs only consider the shortest metric path and consequently you cannot load share across the unequal cost paths. EIGRP is an exception which allows you to do unequal cost load sharing.

That being said the TE approach I mentioned allows you to do unequal cost load sharing by having multiple TE tunnels between two endpoints. This is useful if you already have an MPLS/TE environment and want to load share traffic across multiple paths to the same destination with each path to be allocated a certain percentage of the total load. In the end the hashing will still be flow based and if you have one large volume flow it can offset your load sharing ratios so just keep this in mind.

Atif