in my lab, bigip sends FIN on both sides (client and server side). it is shown at line (1) and (2) in tcpdump when using TCP::close command below.
[root@ve10:Active] config b virtual bar list
virtual bar {
snat automap
pool foo
destination 172.28.19.252:23
ip protocol 6
rules myrule
}
[root@ve10:Active] config b pool foo list
pool foo {
members 200.200.200.101:23 {}
}
[root@ve10:Active] config b self 200.200.200.10 list
self 200.200.200.10 {
netmask 255.255.255.0
vlan internal
allow default
}
[root@ve10:Active] config b rule myrule list
rule myrule {
when CLIENT_ACCEPTED {
TCP::collect 1 0
}
when CLIENT_DATA {
if { [TCP::payload] eq "z" } {
TCP::close
return
}
TCP::release
TCP::collect
}
}
tcpdump when exiting normally (exit command)
14:56:09.431776 IP 200.200.200.101.23 > 200.200.200.10.60462: FP 216:230(14) ack 81 win 46
14:56:09.431792 IP 200.200.200.10.60462 > 200.200.200.101.23: . ack 231 win 4609
14:56:09.431798 IP 172.28.19.252.23 > 192.168.206.33.60462: FP 216:230(14) ack 81 win 3860
14:56:09.433824 IP 192.168.206.33.60462 > 172.28.19.252.23: . ack 231 win 259
14:56:09.434854 IP 192.168.206.33.60462 > 172.28.19.252.23: F 81:81(0) ack 231 win 259
14:56:09.434868 IP 172.28.19.252.23 > 192.168.206.33.60462: . ack 82 win 3860
14:56:09.434872 IP 200.200.200.10.60462 > 200.200.200.101.23: F 81:81(0) ack 231 win 4609
14:56:09.435837 IP 200.200.200.101.23 > 200.200.200.10.60462: . ack 82 win 46
tcpdump when using TCP::close (press z)
(1) 14:56:49.971766 IP 200.200.200.10.60464 > 200.200.200.101.23: F 75:75(0) ack 210 win 4589
(2) 14:56:49.971773 IP 172.28.19.252.23 > 192.168.206.33.60464: F 210:210(0) ack 76 win 3855
14:56:49.972820 IP 200.200.200.101.23 > 200.200.200.10.60464: F 210:210(0) ack 76 win 46
14:56:49.972838 IP 200.200.200.10.60464 > 200.200.200.101.23: . ack 211 win 4589
14:56:49.973879 IP 192.168.206.33.60464 > 172.28.19.252.23: . ack 211 win 260
14:56:49.973889 IP 192.168.206.33.60464 > 172.28.19.252.23: F 76:76(0) ack 211 win 260
14:56:49.973899 IP 172.28.19.252.23 > 192.168.206.33.60464: . ack 77 win 3855