子网中的站点可以浏览互联网，但互相之间无法看到对方 (ip 路由 2 ISP)

在我的路由器（ubuntu/NFTables）上，我配置了两个 WAN，每个 ISP 一个。

在当前配置下，我可以确保子网中的任何机器都可以根据 NFTables 中的规则使用第一个或第二个链接进行导航。

注意不是特定的LAN接口（任何LAN接口上的任何机器都可以根据NFTables中的规则浏览任意两个具有公网IP的链接）

一切正常，好的。

我现在面临的问题是子网上的机器应该互相看到，但它们甚至无法互相 ping 通。

有人知道我该如何修复它，以便除了保持这样的互联网浏览之外，我还可以让连接到 LAN1、LAN2、LAN3 和 LAN4 的机器能够相互通信？

以下是 netplan 配置：

network:
ethernets:
    wan1:
        addresses:
        - 111.31.111.2/28
        - 111.31.111.3/28
        - 111.31.111.4/28
        - 111.31.111.5/28
        - 111.31.111.6/28
        - 111.31.111.7/28
        - 111.31.111.8/28
        - 111.31.111.9/28
        - 111.31.111.10/28
        - 111.31.111.11/28
        - 111.31.111.12/28
        - 111.31.111.13/28
        - 111.31.111.14/28
        nameservers:
            addresses:
            - 8.8.8.8
            - 8.8.4.4
            search: []
        routes:
        - to: default
          via: 111.31.111.1
          metric: 100
        - to: default
          via: 111.31.111.1
          metric: 100
          table: 100
        routing-policy:
        - from: 192.168.10.0/24
          table: 100
        - from: 192.168.20.0/24
          table: 100
        - from: 192.168.30.0/24
          table: 100
        - from: 192.168.40.0/24
          table: 100
    wan2:
        addresses:
        - 222.63.222.10/29
        - 222.63.222.11/29
        - 222.63.222.12/29
        - 222.63.222.13/29
        - 222.63.222.14/29
        nameservers:
            addresses:
            - 8.8.8.8
            - 8.8.4.4
            search: []
        routes:
        - to: default
          via: 222.63.222.9
          metric: 200
        - to: default
          via: 222.63.222.9
          metric: 200
          table: 200
        routing-policy:
        - from: 192.168.10.0/24
          table: 200
        - from: 192.168.20.0/24
          table: 200
        - from: 192.168.30.0/24
          table: 200
        - from: 192.168.40.0/24
          table: 200
    lan1:
        addresses:
        - 192.168.10.1/24
    lan2:
        addresses:
        - 192.168.20.1/24
    lan3:
        addresses:
        - 192.168.30.1/24
    lan4:
        addresses:
        - 192.168.40.1/24
version: 2

下表和规则：

userrouter1@router1:~$ ip route
default via 111.31.111.1 dev wan1 proto static metric 100 
default via 222.63.222.9 dev wan2 proto static metric 200 
192.168.10.0/24 dev lan1 proto kernel scope link src 192.168.10.1 
192.168.40.0/24 dev lan4 proto kernel scope link src 192.168.40.1 
111.31.111.0/28 dev wan1 proto kernel scope link src 111.31.111.2 
222.63.222.8/29 dev wan2 proto kernel scope link src 222.63.222.10

userrouter1@router1:~$ ip rule
0:  from all lookup local
32756:  from 192.168.30.0/24 lookup 200 proto static
32757:  from 192.168.40.0/24 lookup 200 proto static
32758:  from 192.168.20.0/24 lookup 200 proto static
32759:  from 192.168.10.0/24 lookup 200 proto static
32760:  from 192.168.30.0/24 lookup 100 proto static
32761:  from 192.168.10.0/24 lookup 100 proto static
32762:  from 192.168.40.0/24 lookup 100 proto static
32763:  from 192.168.20.0/24 lookup 100 proto static
32766:  from all lookup main
32767:  from all lookup default

userrouter1@router1:~$ ip route show table 100
default via 111.31.111.1 dev wan1 proto static metric 100 

userrouter1@router1:~$ ip route show table 200
default via 222.63.222.9 dev wan2 proto static metric 200 

userrouter1@router1:~$ ip rule show table 100
32760:  from 192.168.30.0/24 lookup 100 proto static
32761:  from 192.168.10.0/24 lookup 100 proto static
32762:  from 192.168.40.0/24 lookup 100 proto static
32763:  from 192.168.20.0/24 lookup 100 proto static

userrouter1@router1:~$ ip rule show table 200
32756:  from 192.168.30.0/24 lookup 200 proto static
32757:  from 192.168.40.0/24 lookup 200 proto static
32758:  from 192.168.20.0/24 lookup 200 proto static
32759:  from 192.168.10.0/24 lookup 200 proto static

就目前情况而言，如果我在机器 192.168.10.10 上，我无法 PING 192.168.20.10，反之亦然...我需要解决这个问题，像这样维持到外部 IP 的导航。

有人能帮助我吗？