Hello,
We have a need to load balance 3 FTP servers. These servers are reached only from a single client IP which is a database server. The FTP method that is being used is currently passive. Our configuration is currently unidirectional, ie, the FTP client (the one database server) sends to the VIP and the FTP Servers then talk directly back to the FTP client and the traffic does not go back through the CSM. The problem is that because FTP negotiates another port to talk on, we have to use sticky so that the connection is sent back to the original FTP server that sent the FTP data port to talk on. But, since we only have a single client IP that is ever used we are not load balancing appropriately across the FTP servers.
Traffic flow goes something like this, tcp port followed after colon as an example
1. FTP Client ----> VIP:21
2. CSM ---------> FTP Server:21
3. FTP Server --------> FTP Client(FTP server says come talk to me on port 1700)
4. FTP Client ---------> VIP:1700
5. CSM ---------> FTP Server:1700
6. FTP Server:1700 ---------> FTP Client
repeat steps 4 thru 6
Here's our hardware and software:
WS-X6066-SLB-APC running 4.2(2)
Config is as follows
module ContentSwitchingModule 9
ft group 101 vlan 9
priority 10
!
vlan 216 client
ip address 10.209.16.31 255.255.252.0
gateway 10.209.16.1
!
vlan 20 server
ip address 10.209.0.31 255.255.252.0
alias 10.209.0.11 255.255.252.0
probe ICMP1 icmp
interval 3
failed 3
receive 3
serverfarm FHEPRT
no nat server
no nat client
real 10.209.0.72
inservice
real 10.209.0.73
inservice
real 10.209.0.71
inservice
probe ICMP1
sticky 106 netmask 255.255.255.255 address source timeout 3
policy FHEPRT_POL1
sticky-group 106
serverfarm FHEPRT
vserver FHEPRT1
virtual 10.209.16.71 any
vlan 216
unidirectional
serverfarm FHEPRT
replicate csrp connection
no persistent rebalance
slb-policy FHEPRT_POL1
inservice
!
