大神们帮帮忙，Openwrt relayd 桥接eth0和wlan0无法通信问题

syj0925

硬件设备：N1盒子
操作系统：Armbian 20.10 Bullseye with Linux 5.9.0-arm-64
需求描述：把N1作为一个无线桥接器，N1的WiFi连接到路由器，N1的以太网口连接PC，为PC提供上网服务，PC、N1和路由器处于同一个局域网。

设计方案：移植OpenWrt的relayd开源组件到N1盒子。运行relayd，命令：<relayd -I wlan0 -I eth0 -D -B -d -d>，把 eth0 和 wlan0 加入到realyd实现伪桥接。

1. git clone https://git.openwrt.org/project/libubox.git     # relayd 依赖 libubox
   
2. git clone https://git.openwrt.org/project/relayd.git       # 编译成功，生成可执行文件：relayd

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问题描述：WiFi连接到路由器，DHCP成功，运行"relayd -I wlan0 -i eth0 -D -B"后，PC DHCP成功，从路由器分配到IP地址，但是PC无法上网，ping <网关IP> 也失败。
问题分析：relayd的Log信息查看，ARP请求成功，但是PC又定期发起ARP请求，猜测是路由设置问题，导致eth0 没有转发到 wlan0。
以上，麻烦帮忙看下什么原因导致的无法上网，非常感谢！

relayd的部分Log信息：
MAC地址:

PC:        e8:6a:64:80:97:9b
eth0:     f2:d3:33:cd:c8:09
wlan0:   b8:27:eb:74:f2:6c
router:  90:de:80:91:a4:51

1. $ ./relayd
   
2. Usage: ./relayd <options>
   
3. 
   
4. Options:
   
5.         -d              Enable debug messages
   
6.         -i <ifname>     Add an interface for relaying
   
7.         -I <ifname>     Same as -i, except with ARP cache and host route management
   
8.                         You need to specify at least two interfaces
   
9.         -G <ip>         Set a gateway IP for clients
   
10.         -R <gateway>:<net>/<mask>
    
11.                         Add a static route for <net>/<mask> via <gateway>
    
12.         -t <timeout>    Host entry expiry timeout
    
13.         -p <tries>      Number of ARP ping attempts before considering a host dead
    
14.         -T <table>      Set routing table number for automatically added routes
    
15.         -B              Enable broadcast forwarding
    
16.         -D              Enable DHCP forwarding
    
17.         -P              Disable DHCP options parsing
    
18.         -L <ipaddr>     Enable local access using <ipaddr> as source address

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eth0: ARP who-has 192.168.137.1, tell 192.168.137.24 (e8:6a:64:80:97:9b)
wlan0: sending ARP who-has 192.168.137.1, tell 192.168.137.24 (b8:27:eb:74:f2:6c)
wlan0: received ARP reply for 192.168.137.1 from 90:de:80:91:a4:51, deliver to 192.168.137.24
eth0: sending gratuitous ARP: 192.168.137.1 is at (f2:d3:33:cd:c8:09)
eth0: sending ARP reply to 192.168.137.24, 192.168.137.1 is at (f2:d3:33:cd:c8:09)

eth0: sending ARP who-has 192.168.137.24, tell 1.1.1.1 (f2:d3:33:cd:c8:09)
wlan0: sending ARP who-has 192.168.137.24, tell 192.168.137.47 (b8:27:eb:74:f2:6c)
eth0: received ARP reply for 192.168.137.24 from e8:6a:64:80:97:9b, deliver to 1.1.1.1
wlan0: sending gratuitous ARP: 192.168.137.24 is at (b8:27:eb:74:f2:6c)

eth0: ARP who-has 192.168.137.1, tell 192.168.137.24 (e8:6a:64:80:97:9b)
wlan0: sending ARP who-has 192.168.137.1, tell 192.168.137.24 (b8:27:eb:74:f2:6c)
wlan0: received ARP reply for 192.168.137.1 from 90:de:80:91:a4:51, deliver to 192.168.137.24
eth0: sending gratuitous ARP: 192.168.137.1 is at (f2:d3:33:cd:c8:09)
eth0: sending ARP reply to 192.168.137.24, 192.168.137.1 is at (f2:d3:33:cd:c8:09)

eth0: ARP who-has 192.168.137.1, tell 192.168.137.24 (e8:6a:64:80:97:9b)
wlan0: sending ARP who-has 192.168.137.1, tell 192.168.137.24 (b8:27:eb:74:f2:6c)
wlan0: received ARP reply for 192.168.137.1 from 90:de:80:91:a4:51, deliver to 192.168.137.24
eth0: sending gratuitous ARP: 192.168.137.1 is at (f2:d3:33:cd:c8:09)
eth0: sending ARP reply to 192.168.137.24, 192.168.137.1 is at (f2:d3:33:cd:c8:09)