Questions about arp_ignore and arp_announce

Arp_announce: integer
The default value is 0.
Limits ARP responses from local IP addresses on Network Interfaces:

Determine the limits to different degrees, and announce the interface for sending ARP requests to local IP addresses
0-(default) any local address on any network interface
1-avoid local addresses that are not in the subnet segment of the network interface. it is useful when the source IP address that initiates an ARP request is set to reach this network interface through a route. check whether the access IP address is one of the IP addresses in the subnet segment of all interfaces. if the access IP address does not belong to the subnet segment of each network interface, level 2 is used for processing.
2-use the most appropriate local address for the query target. in this mode, the source address of the IP packet is ignored and the local address that can communicate with the IP packet is selected. first, select the local address of the destination IP address in the out-of-the-box access subnet of all network interfaces. if no suitable address is found, the current sending network interface or other network interfaces that may receive the ARP response will be selected for sending.

Compare all/and {interface}/at the same time, take a larger value for effect.

Improving the constraint level is beneficial for receiving responses from a specified target, while lowering the level can give more ARP queryers with feedback (I generally do not translate this section about ARP proxy well, take a look at the TCP/IP Bible and then translate it)

Arp_ignore: integer
The default value is 0.
Define different response modes for ARP queries whose target address is a local IP Address

0-(default): responds to ARP query requests from any local IP address on any network interface (for example, eth0 = 192.168.0.1/24, eth1 = 10.1.1.1/24, then, even if eth0 receives an ARP query for 10.1.1.1 from an address such as 10.1.1.2, it will respond-and the original request should appear on eth1, and eth1 should respond)

1-only answers ARP query requests whose target IP address is the local address of the access network interface (for example, eth0 = 192.168.0.1/24, eth1 = 10.1.1.1/24, even if eth0 receives a query for 192.168.0.1 from an address like 10.1.1.2, it does not respond to the ARP query for 10.1.1.1)
2-only answers ARP query requests whose target IP address is the local address of the access network interface, and the access IP address must be in the subnet segment of the network interface (such as eth0 = 192.168.0.1/24, eth1 = 10.1.1.1/24, eth1 receives a query for 192.168.0.1 from an address like 10.1.1.2, but does not respond to the ARP query for 192.168.0.1 initiated for 192.168.0.2)
3-do not reply for local addresses configured with scope host, only resolutions for global and link addresses are replied does not seem to translate well. Please ask me)
4-7-reserved unused
8-does not respond to ARP queries for all (local addresses)

Compare all/and {interface}/at the same time, take a larger value for effect.

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