Configuring VPLS Load Balancing
By default, when there are multiple equal-cost paths to the same destination for the active route, the Junos OS uses a hash algorithm to select one of the next-hop addresses to install in the forwarding table. Whenever the set of next hops for a destination changes, the next-hop address is reselected using the hash algorithm.
You can configure the Junos OS so that, for the active route, all next-hop addresses for a destination are installed in the forwarding table. This feature is called per-packet load balancing. You can use load balancing to spread traffic across multiple paths between routers. You can also configure per-packet load balancing to optimize VPLS traffic flows across multiple paths.
In the VPLS documentation, the word router in terms such as PE router is used to refer to any device that provides routing functions.
You can load-balance VPLS traffic based on Layer 2 media access control (MAC) information, IP information and MPLS labels, or MPLS labels only.
For platform support information, see family multiservice.
To optimize VPLS traffic flows across multiple paths, include
the family multiservice statement at the [edit forwarding-options
hash-key] hierarchy level:
family multiservice { destination-mac; label-1; label-2; payload { ip { layer-3 { (destination-ip-only | source-ip-only); } layer-3-only; layer-4; } } source-mac; symetric-hash { complement; } }
You can configure one or more of the following options to load-balance using the specified packet information:
destination-mac—Include the destination-address MAC information in the hash key for Layer 2 load balancing.source-mac—Include the source-address MAC information in the hash key.label-1—Include the first MPLS label in the hash key. Used for including a one-label packet for per-flow load balancing of IPv4 VPLS traffic based on IP information and MPLS labels.label-2—Include the second MPLS label in the hash key. If bothlabel-1andlabel-2are specified, the entire first label and the first 16 bits of the second label are hashed.payload—Include the packet’s IP payload in the hash key.ip—Include the IP address of the IPv4 or IPv6 payload in the hash key.layer-3-only—Include only the Layer 3 information from the packet’s IP payload in the hash key.layer-3—Include Layer 3 information from the packet’s IP payload in the hash key.destination-address-only—Include only the destination IP address in the payload in the hash key.Note:You can include either the
source-address-onlyor thedestination-address-onlystatement, not both. They are mutually exclusive.source-address-only—Include only the source IP address in the payload in the hash key.Note:You can include either the
source-address-onlyor thedestination-address-onlystatement, not both. They are mutually exclusive.layer-4—Include Layer 4 information from the packet’s IP payload in the hash key.symmetric-hash—Configure the symmetric hash or symmetric hash complement for configuring symmetrical load balancing on an 802.3ad Link Aggregation Group.complement—Include the complement of the symmetric hash in the hash key.
For more information about how to configure per-packet load balancing, see theRouting Policies, Firewall Filters, and Traffic Policers User Guide.