I have created 1 network with 4 nodes.
node 1, An ASUS router at my home behind CGNAT
node 2, A Windows desktop computer at my office
node 3, An Android phone which can be on it data connection, or home network, or office network
node 4, A Windows laptop computer which can be on hotspot of cell phone, or home network, or office network
Regardless which networks node 3 and 4 are on, I can ping among all 4 nodes and got correct responses except between node 1 and node 2.
Node 3 and 4 can ping all nodes.
Node 1 can ping nodes 1,3 and 4, but not 2. Node 2 can ping nodes 2,3,and 4, but not 1.
Does any one know what can be the cause of this problem?