Wifi and wired not talking

Now that I have my two RPi's up and running and accessible I have come up
with a communication problem.
I will use ssh in the following explanation but rlogin and telnet have
similar problems.
The wired and wireless parts of my network don't want to communicate with
each other.
The raspberries can ssh each other over the wifi part of the network and
my two Ubuntu machines can also ssh each other over the wired network.
However, I cannot ssh from Ubuntu to RPi3 when RPi3 is on wifi.
If I wire the RPi3 it can ssh to and from Ubuntu.
All the units can ping each other so some communication is happening.
Also, when Ubuntu (wired) tries to ssh the RPi (wifi) it gets as far as
requesting a password. the password is entered and then it hangs. Control
c does not escape the condition. I have to kill the terminal session.
I realise that this might not actually be a RPi problem but a more
general routing problem.
Maybe there is some obscure setting in /etc/ssh or somewhere which may be
causing this but I have no idea where to start looking.
Best Regards,
Jack Fearnley

Reply to
Jack Fearnley
Loading thread data ...
So the routing is good, but you may have a problem with TCP sessions between wired and wireless or you may have an authentication problem, do rlogin and telnet fail after password entry too ?
If everything always fails just after password entry it's worth setting up some kind of unauthenticated service at both ends (ftp with anonymous or thttpd serving static pages - anything simple like that) and see if it works with client on wifi server on wired and vice-versa. If that works both ways then authentication is the place to look, if it fails then it's a TCP problem - MTU mismatch perhaps.
Can you ssh from the RPi3 on wifi to the Ubuntu box on the wired lAN ?
I'm thinking this is some kind of problem between the wired and wireless networks - are they routed or bridged together ?
Given that rlogin and telnet also have problems I wouldn't waste time thinking about ssh config.
--
Steve O'Hara-Smith                          |   Directable Mirror Arrays 
C:\>WIN                                     | A better way to focus the sun 
 Click to see the full signature
Reply to
Ahem A Rivet's Shot
sessions
See below.
No.
To be precise
telnet responds with telnet: Unable to connect to remote host: Connection refused
rlogin responds with the same freeze as ssh.
formatting link

Jack
Reply to
Jack Fearnley
Strikes me that the problem might be a bit fundemental. LAN and WiFi in the same subnet? (check net masks, but I think that would break ping). Only one DHCP server (if using DHCP). Remember that ports have IP address's not machines, so the wired port on a Pi should have different IP address to the WiFi port.
--
Cheers 
Dave.
Reply to
Dave Liquorice
You are correct. The IP addresses are different. But that gets me no nearer a solution.
Jack
Reply to
Jack Fearnley
Assuming the wired & wireless router are one and the same device (e.g. your DSL modem), then it's probably a security feature in your router to keep them separate. Maybe your wifi is configured as a "guest network"?
Reply to
A. Dumas
OK that really points to networking rather than client/server config or authentication issues.
Hmm, presumably telnetd is running and not blocked.
I think you'll find the answer in your wifi router configuration, possibly MTU related.
--
Steve O'Hara-Smith                          |   Directable Mirror Arrays 
C:\>WIN                                     | A better way to focus the sun 
 Click to see the full signature
Reply to
Ahem A Rivet's Shot
Isn't this the same issue asked about in this post by the same OP
"problems with ssh" on Thu, 14 Dec 2017 16:33:07 -0000 (UTC) ?
Reply to
mm0fmf
Hmph, I see, and the same suggestion.
Reply to
A. Dumas
Most likely your router is set up to separate wired from wifi connections.
Possibly has a 'guest' network on wifi that only allows internet access, not access to the wired LAN
--
"Corbyn talks about equality, justice, opportunity, health care, peace,  
community, compassion, investment, security, housing...." 
 Click to see the full signature
Reply to
The Natural Philosopher
A different description of the WiFi being a "guest" subnet with access only to other WiFi clients and the 'net.
MTU shouldn't affect the higher level protocols as any split packets should be reassemabled before being passed up a level. Note the use of the word "shouldn't" and "should"...
--
Cheers 
Dave.
Reply to
Dave Liquorice
Yes it is, but I got zero responses that time and Christmas intervened so I let it drop. Also my VNC configuration meant I no longer needed ssh.
I now have two RPi's and which clarifies the issue.
Jack
Reply to
Jack Fearnley
So, the guest network hypothesis seems to be the favorite right now. I shall study my router. It is a D-Link WBR-1310 if any of you are familiar with it.
Some additional factoids:
If I ssh to the RPi3 and give a false password it says 'permisson denied. Try again'
My main computer (Ubuntu) has wired ip address 192.168.0.101 and wifi address 192.168.0.104. I CANNOT ssh from my RPi's to 192.168.0.104 even though they are all on the wifi network at that point!
Jack
Reply to
Jack Fearnley
What does ssh -vvv say when you try from a wired machine to one on wifi? And vice-versa?
Reply to
mm0fmf
Have you tried pinging the PI's from the wired network and back?
--

-TV
Reply to
Tauno Voipio
it is usually a bit extreme but eventually you may need to try running wire-shark (Possibly on both the PC & the PI) to get full indication of what is happening on the network.
--
Freedom from incrustation of grime is contiguous to rectitude.
Reply to
alister
Before you get to wireshark, have you tried nmap? From main machine to PIs and vice-versa (sudo apt-get install nmap).
--

Chris Elvidge, England
Reply to
Chris Elvidge
Yes. No problems.
I should also mention that I have full VNC communication between Ubuntu and the RPi3.
Jack
Reply to
Jack Fearnley
It gives a huge output mostly saying that various files don't exist on / home/jack/.ssh
In fact the only file there is known_hosts.
The last line is the password request. I don't think posting the whole thing would be useful but I can if you wish.
Jack
Reply to
Jack Fearnley
Wtf. You shoud have mentioned that earlier.
Reply to
A. Dumas

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.