How to limit connection lifetime in Mikrotik for IPv6?

Question

Computer networks

Firewall options:

# aug/10/2016 09:32:07 by RouterOS 6.36
# software id = X5Q5-12IU
#
/ipv6 firewall filter
add chain=input limit=100,5:packet protocol=icmpv6
add action=drop chain=input protocol=icmpv6
add chain=forward limit=100,5:packet protocol=icmpv6
add action=drop chain=forward protocol=icmpv6
add action=drop chain=input dst-address-list=local log-prefix=""
add action=accept chain=input comment="http(s)" connection-state=established,related,new dst-address-list=web-srvs dst-port=80,443 log-prefix="" \
    protocol=tcp
add action=accept chain=input connection-state=established,related log-prefix=""
add action=drop chain=input connection-state=invalid,new log-prefix=""
add action=accept chain=forward connection-state=!invalid in-interface=ether1-gateway log-prefix="" out-interface=bridge-local
add action=drop chain=forward in-interface=ether1-gateway out-interface=ether1-gateway
add action=drop chain=forward connection-state=invalid log-prefix=""

/ipv6 firewall mangle
add action=accept chain=prerouting log-prefix=""
add action=accept chain=forward log-prefix=""
add action=accept chain=postrouting log-prefix=""

At the same time, I observe more than 200 "established" connections with a lifetime of more than 15 days.
What is the reason for this? How to limit the maximum connection lifetime?

Answer 1

/ip firewall connection tracking, more