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

[James Jun]

Hi Waris,

One question I have about load-balancing on ASR920.  If the device is acting as PE for L2VPN, how does one actually achieve load balancing out to the CE facing LAG interface?

The CE facing configuration is contained in an EFP, and according to IOS XE documentation, EFPs inside a port-channel are not load balanced within (i.e. egress traffic only goes out on one member links).

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.

James


!
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
!