firewall ipv6 reverse-route load-balance enable

By default, the load balancing function for IPv6 reverse routes is disabled.

After equal-cost routes are configured, sticky load balancing is enabled by default. If forward traffic is uneven, load unbalance occurs on reverse traffic. As a result, some interfaces may be overloaded. For scenarios where persistent connections exist and the traffic volume is large, or where a large number of GRE packets exist (GRE packets centralize at the inbound interface), you need to enable the load balancing function for reverse routes to allocate reverse traffic to interfaces in load balancing mode as configured by the firewall ipv6 load-balance { flow | packet } command.