[c-nsp] MPLS load-balancing on ME-3800X

[James Jun]

Hello all,

Thanks for the responses.

> I believe the ASR920 is capable of load balancing on egress port channel. It depends of course on the hashing algorithm but certainly the actual payload must "contain" several flows that will be identified and will be sent to different members.
> 

So here is an interesting observation -- this is on ASR920-24SZ-IM running 3.16.4(S).

(1) As of 3.16.4S, "src-dst-mixed-ip-port - Source XOR Destination Port, IP addr" option is now available as a configurable
    parameter under 'port-channel load-balance-hash-algo' command.  I did not see this command before on previous IOS XE
    versions for ASR920.

(2) When configuring 'port-channel load-balance-hash-algo src-dst-mixed-ip-port', the device does NOT load balance using
    src/dst IP + tcp/udp ports as the command describes.  Instead, it appears to be doing src/dst IP pair load balancing 
    where traffic does not balance well at all.  This was the observation I made in my earlier email below.

(3) When configuring 'port-channel load-balance-hash-algo  src-dst-ip', we now see the ASR920 load balancing traffic using
    full src/dst IP + tcp/udp ports hash.  Traffic balances fairly evenly across both member links now on passenger traffic
    with several L4 flows on them.

So it seems to be a cosmetic bug or I probably misread the documentation.  The solution is to use 'src-dst-ip' hash setting instead of src-dst-mixed-ip-port.

James


> Consider this configuration on a sample PE below.  As you can see, the attachment of the customer onto L2VPN is on an EFP.  Traffic exiting the L2VPN/VFI and egressing port-channel20 toward the customer never gets load-balanced and the entire EFP traffic is mapped to one member link.
> 
> 
> !
> port-channel load-balance-hash-algo src-dst-mixed-ip-port
> !
> l2 vfi test-vpls
>  vpn id 98
>  bridge-domain 20
>  mtu 1500
>  neighbor 10.1.100.34 encapsulation mpls
> !
> interface Port-channel20
>  description LAG to Customer/CE
>  service instance 1 ethernet
>   description EFP for L2VPN Service
>   encapsulation untagged
>   l2protocol peer lacp
>   bridge-domain 20
>   mac security
>  !
> !
> interface GigabitEthernet0/0/0
>  description To CE: LAG Member #1 of 2
>  channel-group 20 mode active
> !
> interface GigabitEthernet0/0/1
>  description To CE: LAG Member #2 of 2
>  channel-group 20 mode active
> !