Configuring selective dynamic load balancing

Configure a selective load balancing policy

The following example configures a selective dynamic load balancing policy. Traffic matching the policy uses static ECMP load-balancing, not dynamic.

--{ + candidate shared default }--[  ]--
# info with-context network-instance default policy-forwarding
    network-instance default {
        policy-forwarding {
            policy slb1 {
                type selective-load-balancing
                rule 101 {
                    action {
                        load-balance static
                    }
                    match {
                        rdma-opcode 100
                        ipv4 {
                            protocol udp
                            destination-ip {
                                prefix 10.10.10.0/24
                            }
                        }
                        transport {
                            destination-port https
                        }
                    }
                }
            }
        }
    }

Apply the selective dynamic load balancing policy

A selective DLB policy is applied globally on a network-instance, meaning it applies to all subinterfaces within the network-instance in which it is configured. The following example applies a selective DLB policy in a network-instance.

--{ + candidate shared default }--[  ]--
# info with-context network-instance default policy-forwarding global-selective-load-balancing-policy
    network-instance default {
        policy-forwarding {
            global-selective-load-balancing-policy slb1
        }
    }

Configure the default system load-balancing behavior

For traffic matching DLB-enabled prefixes that does not match a selective DLB policy, you can configure the default DLB behavior to be either static or dynamic. The static setting causes traffic matching DLB-enabled prefixes to not use dynamic load balancing for ECMP distribution of packets over outgoing links, while the dynamic setting causes the traffic to use dynamic load balancing; the default is dynamic.

The following example configures the default system load-balancing behavior to be static, so traffic matching DLB-enabled prefixes does not use dynamic load balancing.

--{ +* candidate shared default }--[  ]--
# info with-context system load-balancing
    system {
        load-balancing {
            dynamic {
                default-load-balancing static
            }
        }
    }

Display TCAM resources used by selective DLB policies

Before a selective DLB policy is applied, the reserved and programmed statistics are both 0, and free-static statistic is 254. After a 1-rule policy is applied, the resources are adjusted as shown in the following example:

--{ running }--[  ]--
# info from state platform linecard 1 forwarding-complex 0 tcam resource policy-forwarding-selective-load-balancing
    free-static 252
    reserved 2
    programmed 2

The reserved statistic is the number of TCAM entries allocated to applied selective DLB policies, programmed is how many TCAM entries are installed in hardware, and free-static is the number of remaining TCAM entries.

Display TCAM entries per selective DLB policy rule

The following example displays the number of TCAM entries used by a specific rule in a selective DLB policy.

--{ running }--[  ]--
# info from state network-instance default policy-forwarding policy p1 rule 10
    tcam-entries {
        forwarding-complex "(0,0)" {
            tcam-entries 1
        }
        forwarding-complex "(1,0)" {
            tcam-entries 1
        }
    }

The tcam-entries statistic shows a rule's footprint on each forwarding complex.

Display matched packets and octets per selective DLB rule

The following example displays a count of the matched-packets and matched-octets that matched a specific selective DLB rule.

--{ running }--[  ]--
# info from state network-instance default policy-forwarding policy p1 rule 10 statistics
    matched-packets 9427143
    matched-octets 9389434428