[f-nsp] serveriron XL not detecting unresponsive ports

[network at cwo.com]

Hello,

I'm still using a foundry ServerIron XL to do some load balancing between
our mail servers.
When both my servers are up on running (on all load balanced ports) the
ServerIron nicely balances the load between the 2 servers. However, I've
noticed today, while I took on of the 2 servers down for maintenance, that
the ServerIron is not taking the unresponsive server out of the chain.
Therefore, my customers where now getting timeouts since their traffic was
being directed by the foundry to the unresponsive server.
I don't see the problem with my config, but obviously there is something
missing.

Here is my config:

Current configuration:
!
ver 07.1.21lT42
!
!
!
server no-fast-bringup
server predictor round-robin
server sticky-age 10

server port 587
 tcp
 udp

server port 993
 tcp
 udp

server port 995
 tcp
 udp

server port 80
 tcp
 tcp l4-check-only
!
!
server real frontend xxx.xxx.xxx.21
 port http
 port http keepalive
 port http url "HEAD /"
 port 587
 port 587 keepalive
 port smtp
 port smtp keepalive
 port pop3
 port pop3 keepalive
 port ssl
 port imap4
 port imap4 keepalive
 port 993
 port 993 keepalive
 port 995
 port 995 keepalive
!
server real backend xxx.xxx.xxx.22
 port http
 port http keepalive
 port http url "HEAD /"
 port 995
 port 995 keepalive
 port 993
 port 993 keepalive
 port imap4
 port imap4 keepalive
 port ssl
 port pop3
 port pop3 keepalive
 port smtp
 port smtp keepalive
 port 587
 port 587 keepalive
!
!
server virtual mail xxx.xxx.xxx.4
 port 995 sticky
 port 993 sticky
 port imap4 sticky
 port ssl sticky
 port http sticky
 port pop3 sticky
 port smtp sticky
 port 587 sticky
 bind 995 frontend 995 backend 995
 bind 993 frontend 993 backend 993
 bind imap4 frontend imap4 backend imap4
 bind ssl frontend ssl backend ssl
 bind http frontend http backend http
 bind pop3 frontend pop3 backend pop3
 bind smtp frontend smtp backend smtp
 bind 587 frontend 587 backend 587
!




!



!
vlan 1 name DEFAULT-VLAN by port

!
!
aaa authentication login default enable
boot sys fl pri
enable telnet authentication
enable telnet password .....
enable super-user-password .....
hostname mail
ip address xxx.xxx.xxx.38 255.255.255.0
ip default-gateway xxx.xxx.xxx.1
ip dns domain-name cwo.com
ip dns server-address xxx.xxx.xxx.2 xxx.xxx.xxx.3
username root password .....
no snmp-server
!
end


What am I missing?

Thanks for your time



JB