Some systems on home network can't reach each other
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Ping is a poor test.
Since all of them can reach the internet then I'd consider this to be a firewall issue.
One some home routers they jail the connections between wired and wireless.
Yes ping is crude, but it's a simple first test.
If it's an external firewall (such as the router), wouldn't it divide the systems into two unconnected groups, e.g. wired/wireless? As you can see from the connectivity diagram, there's not a clean division like that.
If it's firewalls in the systems, wouldn't that require firewalls in all non-contactable systems? I.e. Windows, iPad, and Linux? Android is the only one that all other systems can reach.
I drew a diagram of "what systems can ping what other systems" to visualize it better -- below.
Quote:
Originally Posted by teckk
Map the network and see who is listening to what.
Also see what the router is doing with what machines:
Code:
traceroute 192.16.0.1
As you'd expect, it's one hop from all systems. They're all connected directly to the router via wifi or (for Linux) LAN.
Unfortunately nmap is not on my system, and I can't get the installer (yum) to work. Still poking at it.
Windows' firewall is on by default. If you turn it off, you get nagged to turn it back on and sometimes it turns itself back on when you're not looking. Have you turned it off?
I hadn't, but I tried it. I turned off the Windows Defender firewall for the local private network. Only change I see is that the Linux system can no longer ping Windows. But that may have been an error before -- I still can't ping Linux -> Win after turning the firewall back on.
You are telling nothing about you network setup, but I presume most of your devices are connected via wi-fi and if it is at least dual-band. Some buggy routers have issues with communication between bands, try locking all your devices to a single band. Also many routers have a wireless isolation security option which intentionally prevents wireless devices from communicating with other devices on the network - check configuration of your router to see if it is enabled.
The Linux system is connected via Ethernet LAN. All others (Win, Android, iOS) are on 5G IPv4 wifi.
The router (Arris TG3452A) has a firewall, but it's set to minimum security (nothing blocked). It supports "Home" and "Guest" networks. Each has an AP Isolation setting, which is currently On on the Guest network, Off on the Home network (where I work). I disabled it on both networks and saw no change.
Your Android phone and iPad may be configured for random MAC addresses when then connect which if you did not always check could cause part or your problem and I think that there is an iPad setting to regenerate a new mac every 24 hours.
Obviously the desktop would not change and then compounded by if you are using the guest access point for some devices.
Since all of them can reach the internet then I'd consider this to be a firewall issue.
One some home routers they jail the connections between wired and wireless.
PING is a poor test, and one used by so much malware that some systems have the ECHO protocol it depends upon blocked. There is also a network "stealth mode" that prevents an "echo" reply. I recommend using several tools, not all based upon ping.
Guest network by design usually blocks inter lan access.
I assumed it probably did. But I don't use it. My housemate uses that network.
Quote:
Originally Posted by jefro
What does arp -a tell?
Attached below.
Quote:
Originally Posted by michaelk
Your Android phone and iPad may be configured for random MAC addresses
That would not explain Windows' inability to reach Linux, would it?
Quote:
Originally Posted by wpeckham
PING is a poor test, ... I recommend using several tools, not all based upon ping.
I used several tools on Win/iOS/Android/Linux, but I think most of them were using ping. What tools would you suggest? I still haven't resolved the yum install issue on Linux so I have limited options there.
Interesting. When I did my tests yesterday, Windows and Linux could not reach iOS. I just did a test ping from Linux to iOS and it hung up. I left it runnning -- and several minutes later the pings started working. Now Windows can reach iOS too.
arp -a output:
Code:
? (192.168.0.254) at c0:25:e9:57:11:85 [ether] on enp0s2f1u2c2
? (192.168.0.137) at c2:25:e9:b0:71:e6 [ether] on enp0s2f1u2c2
arrisatom (192.168.0.1) at 48:4e:fc:eb:00:21 [ether] on enp0s2f1u2c2
arrisatom (192.168.0.1) at <incomplete> on virbr0
? (192.168.0.11) at <incomplete> on enp0s2f1u2c2
SAMSUNG-SM-G950U (192.168.0.156) at a0:cc:2b:b0:71:e6 [ether] on enp0s2f1u2c2
SPECTRE (192.168.0.218) at 48:a4:72:45:b3:5c [ether] on enp0s2f1u2c2
? (192.168.0.61) at b2:45:b6:e6:e5:cd [ether] on enp0s2f1u2c2
? (192.168.0.164) at b2:45:b6:e6:e5:cd [ether] on enp0s2f1u2c2
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