LVS-TUN Tunnel Mode

Sure. Below is a lab manual in tabular form organized according to your requirements:

Host Name	NIC Information	Installation of applications	systems
Client	192.168.2.101	not have	RHEL8/CentOS8
Lvs server (DR)	DIP:192.168.2.110 VIP:192.168.40.111	ipvsadm	RHEL8/CentOS8
RS1	RIP:192.168.2.111	httpd	RHEL8/CentOS8
RS2	RIP:192.168.2.112	httpd	RHEL8/CentOS8

Each host here has its own specific features and configurations:

Client: Used to initiate a request.
Lvs server (DR): Acts as a load balancer, responsible for receiving and distributing traffic.
RS1 cap (a poem)RS2: Acts as a real server and handles requests from the load balancer.

Load Balancer (LB)

To save the IPVS configuration.

ipvsadm --save > /etc/sysconfig/ipvsadm

Enable IP Forwarding.

echo "net.ipv4.ip_forward = 1" >> /etc/
sysctl -p

Configure the TUN interface.

ifconfig tunl0 192.168.2.200 broadcast 192.168.2.200 netmask 255.255.255.255 up

Create a virtual server and set up polling scheduling.
```
ipvsadm -A -t 192.168.2.200:80 -s rr
```

Add real servers.

ipvsadm -a -t 192.168.2.200:80 -r 192.168.2.111:80 -i
ipvsadm -a -t 192.168.2.200:80 -r 192.168.2.112:80 -i

Disabling the firewall with SELinux.
```
systemctl stop 
setenforce 0
```
Verify the IPVS configuration.
```
ipvsadm -ln
```

Real Server 1 (RS1)

Start the HTTP service.
```
systemctl start httpd
```
Disable SELinux and firewalls.
```
setenforce 0
systemctl stop 
```
Configure site content.
```
echo "this is web1" >> /var/www/html/
```
Test site.
```
curl 127.0.0.1
```

Configure the TUN interface.

ifconfig tunl0 192.168.2.200 broadcast 192.168.2.200 netmask 255.255.255.255 up

Adjust sysctl settings.

echo "net..tunl0.arp_ignore = 1" >> /etc/
echo "net..tunl0.arp_announce = 2" >> /etc/
echo "net..arp_ignore = 1" >> /etc/
echo "net..arp_announce = 2" >> /etc/
echo "net..tunl0.rp_filter = 0" >> /etc/
echo "net..rp_filter = 0" >> /etc/
sysctl -p

Real Server 2 (RS2)

Start the HTTP service.
```
systemctl start httpd
```
Disable SELinux and firewalls.
```
setenforce 0
systemctl stop 
```
Configure site content.
```
echo "this is web2" >> /var/www/html/
```
Test site.
```
curl 127.0.0.1
```

Configure the TUN interface.

ifconfig tunl0 192.168.2.200 broadcast 192.168.2.200 netmask 255.255.255.255 up

Adjust sysctl settings.

echo "net..tunl0.arp_ignore = 1" >> /etc/
echo "net..tunl0.arp_announce = 2" >> /etc/
echo "net..arp_ignore = 1" >> /etc/
echo "net..arp_announce = 2" >> /etc/
echo "net..tunl0.rp_filter = 0" >> /etc/
echo "net..rp_filter = 0" >> /etc/
sysctl -p

test (machinery etc)

Test Load Balancer.

curl 192.168.2.200

[root@localhost ~]# curl 192.168.2.200
this is web2
[root@localhost ~]# curl 192.168.2.200
this is web1
[root@localhost ~]# curl 192.168.2.200
this is web2
[root@localhost ~]# curl 192.168.2.200
this is web1
[root@localhost ~]# curl 192.168.2.200
this is web2
[root@localhost ~]# curl 192.168.2.200
this is web1
[root@localhost ~]# curl 192.168.2.200
this is web2
[root@localhost ~]# curl 192.168.2.200
this is web1