Use VRRP to back up two-way routing links (Figure)

Article title: using VRRP to back up two-way routing links (figure ). Linux is a technology channel of the IT lab in China. Includes basic categories such as desktop applications, Linux system management, kernel research, embedded systems, and open source.
In the previous experiment of VRRP (using VRRP for simple router backup), only one interface of the Linux router can be backed up, but the router usually has at least two interfaces, when either of the two interfaces fails, the network will fail, so we need to monitor the two interfaces in Linux, when any network interface of the Master Linux router fails, the Backup Linux router takes over the work of the Master. It is easy to implement in Keepalived.
　　
Experiment name: use VRRP to back up two-way routing links
OS: RedHat 7.3
Kernel used: linux-2.4.24
Module used in the experiment: keepalived-1.16.tar.gz (if you do not know much about VRRP and Keepalived, first look here)
　　
Shows the network structure:
　　 　
There are two Linux Router in the network:
　　
(1), Master (eth0: 192.168.1.10/24 connected to the Internet; eth1: 192.168.3.1/24 connected to the intranet)
　　
(2), Backup (eth0: 192.168.2.10/24 connected to the Internet; eth1: 192.168.3.2/24 connected to the intranet)
　　
The intranet IP address segment is 192.168.3.0/24, and the Gateway (V-Gate) is 192.168.3.3/24. remember that the address 192.168.3.3/24 takes effect when Keepalived is started.
　　
First, install keepalived-1.1.6.tar.gz on Linux Router master. for details, see (using VRRP to implement simple Router backup)
　　
Configure VRRP for the Linux Router Master,
# Vi/usr/local/keepalived/etc/keepalived. conf
　　
The content is as follows:
　　
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Vrrp_instance VI_1 {
State MASTER
Interface eth1
Track_interface {# Interfaces state we monitor
Eth0
}
　　
Virtual_router_id 51
Priority100
Advert_int 1
Authentication {
Auth_type PASS
Auth_pass 1111
}
Virtual_ipaddress {
192.168.3.3
}
}
　　
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The methods for installing keepalived on Linux Router Backup are the same. The difference is that the configuration file/usr/local/keepalived/etc/keepalived. conf is as follows:
　　
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Vrrp_instance VI_1 {
State BACKUP
Interface eth1
Track_interface {# Interfaces state we monitor
Eth0
}
　　
Virtual_router_id 51
Priority100
Advert_int 1
Authentication {
Auth_type PASS
Auth_pass 1111
}
Virtual_ipaddress {
192.168.3.3
}
}
　　
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Start keepalived on Backup in the same way
#/Usr/local/keepalived/sbin/keepalived? D? F/usr/local/keepalived/etc/keepalived. conf
　　
In this way, if any of the eth0 and eth1 interfaces on the Master node fail, Backup will obtain the message through the MultiCast address: 224.0.0.18, and take over the address 192.168.3.3.
　　
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　　 Summary
　　
This experiment differs from VRRP for simple vro backup because there are multiple items in their configuration files:
Track_interface {# Interfaces state we monitor
Eth0
}
Track_interface means to monitor the network interface card you want to monitor in Linux. when one of the interfaces fails, keepalived is regarded as a router failure.