I have configured LVS on cent os using piranha tool .I am using vip of internal n/w as gateway for real server we have two NIC one having exteranl Ip and other for internal n/w which is on 192.168.3.0/24 network. But I am not able to connect from client it shows connection refused error . Please suggest iptables rules for private n public n/w to communicate. May be I am missing this . Iptables rules that we have added are : iptables -t nat -A POSTROUTING -p tcp -s 192.168.3.0/24 --sport 5000 -j MASQUERADE this is my ipconfig: eth0 Link encap:Ethernet HWaddr 00:00:E8:F6:74:DA inet addr:122.166.233.133 Bcast:122.166.233.255 Mask:255.255.255.0 inet6 addr: fe80::200:e8ff:fef6:74da/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:94433 errors:0 dropped:0 overruns:0 frame:0 TX packets:130966 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:9469972 (9.0 MiB) TX bytes:19929308 (19.0 MiB) Interrupt:16 Base address:0x2000 eth0:1 Link encap:Ethernet HWaddr 00:00:E8:F6:74:DA inet addr:122.166.233.136 Bcast:122.166.233.255 Mask:255.255.255.0 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 Interrupt:16 Base address:0x2000 eth1 Link encap:Ethernet HWaddr 00:E0:20:14:F9:2D inet addr:192.168.3.1 Bcast:192.168.3.255 Mask:255.255.255.0 inet6 addr: fe80::2e0:20ff:fe14:f92d/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:123718 errors:0 dropped:0 overruns:0 frame:0 TX packets:148856 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:18738556 (17.8 MiB) TX bytes:11697153 (11.1 MiB) Interrupt:17 Memory:60000400-600004ff eth1:1 Link encap:Ethernet HWaddr 00:E0:20:14:F9:2D inet addr:192.168.3.10 Bcast:192.168.3.255 Mask:255.255.255.0 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 Interrupt:17 Memory:60000400-600004ff eth2 Link encap:Ethernet HWaddr 00:16:76:6E:D1:D2 UP BROADCAST MULTICAST MTU:1500 Metric:1 RX packets:0 errors:0 dropped:0 overruns:0 frame:0 TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:0 (0.0 b) TX bytes:0 (0.0 b) Interrupt:21 Base address:0xa500 and ipvsadm -ln command [root@abts-kk-static-133 ~]# ipvsadm -ln IP Virtual Server version 1.2.1 (size=4096) Prot LocalAddress:Port Scheduler Flags -> RemoteAddress:Port Forward Weight ActiveConn InActConn TCP 122.166.233.136:5000 wlc TCP 122.166.233.136:5004 wlc lvs server routing table Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 192.168.3.0 0.0.0.0 255.255.255.0 U 0 0 0 eth1 122.166.233.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0 192.168.122.0 0.0.0.0 255.255.255.0 U 0 0 0 virbr0 169.254.0.0 0.0.0.0 255.255.0.0 U 1003 0 0 eth0 169.254.0.0 0.0.0.0 255.255.0.0 U 1004 0 0 eth1 0.0.0.0 122.166.233.1 0.0.0.0 UG 0 0 0 eth0 real 1 real 2 we have configured various ports from 5000:5008 . Do we need to this iptables for all ports? Suggest me how should I solve this issue.