It may be observed that even after configuring Services Offload, all traffic is still handled by the Services Processing Unit (SPU).

This article demonstrates that inbound and outbound interface maximum transmission unit (MTU) values must be equal for Services Offload to work properly.

Even after Services Offload is configured, traffic is still being handled by the SPU. Note that the following counter in show usp flow counters all in the SPU is constantly increasing:

Flow Services-offload(SO) Related Counters
========================
SO session check unequal mtu        1211343
SO session check unequal mtu        2424441
SO session check unequal mtu        2426274
SO session check unequal mtu        2427589

When the corresponding interface configuration is checked, it is seen that the inbound interface MTU value of AE0 is 9192, whereas the outbound interface MTU value of AE1 is 2028.

ae0 {
    mtu 9192;
    aggregated-ether-options {
        lacp {
            active;
        }
    }
    unit 0 {
        family inet {
            address 10.10.9.1/30;
        }
    }
}
ae1 {
    mtu 2028;
    aggregated-ether-options {
        lacp {
            active;
        }
    }
    unit 0{
        family inet {
            address 10.10.10.1/30;
        }
    }
}

Ensure that both inbound and outbound interface MTU values are equal. If the MTU values are different, Services Offload does not work as expected.