LVS : configure DSR ( Direct Server Return )

Here are logs when configuring LVS direct server return.

     Client

       |

     L2SW

|eth0      | eth0

LVS      L3SW

|eth1      |eth1

     L2SW

       |

     Server ( httpd )

request packets : client -> LVS -> Server

reply packets : server -> L3SW -> Client

Default GW of http server : L3SW eth1 ( not LVS’s eth1 )

[ L3SW ]

I used CentOS6 as L3SW.

disable rp_filter and enable ip_forward.

# echo 0 > /proc/sys/net/ipv4/conf/eth1/rp_filter # echo 1 > /proc/sys/net/ipv4/ip_forward

[ LVS ]

install LVS(ipvsadm) over yum

[root@centos7-lvs ~]# cat /etc/centos-release CentOS Linux release 7.1.1503 (Core) [root@centos7-lvs ~]# yum install -y ipvsadm

[root@centos7-lvs ~]# echo 1 > /proc/sys/net/ipv4/ip_forward [root@centos7-lvs ~]# echo 0 > /proc/sys/net/ipv4/conf/eth1/rp_filter

add TCP 80 load balancing rule.

[root@centos7-lvs ~]# ipvsadm -A -t 192.168.122.43:80 -s rr [root@centos7-lvs ~]# ipvsadm -a -t 192.168.122.43:80 -r 192.168.150.150::80 –g

--

      [packet-forwarding-method]

             -g, --gatewaying  Use gatewaying (direct routing). This  is  the

             default.

--

[root@centos7-lvs ~]# ipvsadm –Ln IP Virtual Server version 1.2.1 (size=4096) Prot LocalAddress:Port Scheduler Flags  -> RemoteAddress:Port           Forward Weight ActiveConn InActConn TCP  192.168.122.43::80 rr  -> 192.168.150.150::80           Route   1      0          0

I would like to add “VIP” as an alias IP, but how can I do that with nmcl?

I will add VIP with ifconfig command.

[root@centos7-lvs ~]# yum install -y net-tools [root@centos7-lvs ~]# ifconfig eth0:10 192.168.122.43

[ Server ]

on the httpd server,

# iptables -t nat -A PREROUTING -d 192.168.122.43 -j REDIRECT nf_conntrack version 0.5.0 (16384 buckets, 65:806 max)

You don’t need to configure LVS’s VIP on the server.

start the apache

# /etc/init.d/httpd start