Studying a networking problem

[Liamdale]

I don't know if I am in the right place but here is my problem. I am learning and configuring my new computer. When it comes to networks, I have general knowledge but no practical experience. My old computer had ubuntu 14.04 and the network use I needed was handled automatically. I have a TV media player with a hard disk connected to it. Ubuntu could access the hard disk. Kubuntu can see the hard disk occasionally but most of the time it can't see it. The few times it did see the HDD I couldn't access it.

I started to read up on network access and found that I could identify my computer's IP address by using ifconfig. My use of ifconfig produced the following read out at the terminal:

$ ifconfig -a
enp0s31f6: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 192.168.0.105 netmask 255.255.255.0 broadcast 192.168.0.255
inet6 fe80::b9fa:d22f:b985:76fc prefixlen 64 scopeid 0x20<link>
ether 60:45:cb:a3:84:75 txqueuelen 1000 (Ethernet)
RX packets 23957 bytes 22683420 (22.6 MB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 18022 bytes 2291574 (2.2 MB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
device interrupt 16 memory 0xf7200000-f7220000

lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10<host>
loop txqueuelen 1000 (Local Loopback)
RX packets 492 bytes 48334 (48.3 KB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 492 bytes 48334 (48.3 KB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

All documentation made reference to eth0 to get the IP.

Checking for eth0 produced:

$ ifconfig eth0
eth0: error fetching interface information: Device not found

Trying to track down my network problem, why would my IP command produce a different result than the documentation or even my old computer which has an eth0 readout.

Is my documentation out of date? Can anyone point me to a link or data source where I can better understand how to correct my network access problem.

My old computer was a 32 bit pentium 4 with Ubuntu 14.04. My new computer is a 64 bit i5 4core cpu with Kubuntu 17.04

[Batty]

HI, instead of eth0 your network device appears as "enp0s31f6"

Ubuntu server documentation gives lots of network advice = https://help.ubuntu.com/lts/serverguide/

Also the Arch linux wiki is a good source of information = https://wiki.archlinux.org/index.php/Network_configuration

[oshunluvr]

After 14.04, udev defaults to identifying the network devices with descriptive names rather than the generic ones like eth0. https://www.freedesktop.org/wiki/Sof...nterfaceNames/

However, unless I missed it, you haven't described the issue. Is there some problem being caused by using enp0s31f6 instead of eth0? You say there's a problem, but I can't see what it is.

[oshunluvr]

A re-read later; it looks like you're having trouble accessing your "TV media player"? I doubt this has anything to do with the device name of your NIC. Try describing your devices in detail and the symptoms of your issue.

[Liamdale]

You are right Oshunluvr, The device name is not an indication that my network setup is wrong. Further research has shown that the eth0 .. eth1 is being replaced with predetermined device names: https://www.freedesktop.org/wiki/Sof...nterfaceNames/.

In my root, at /etc/network I found a file called devnames which contains the device name "enp0s31f6". I agree that the two situations are unrelated. The hard disk access is an inconvenience but I still need to improve my knowledge of networks to be able to solve this problem.

Thanks for the input

[oshunluvr]

So to the issue: What's the "TV media device" and how does it share it's hard drive? My guess would be SAMBA but it could be DLNA. The solutions to either are quite different.

[Liamdale]

I continued to experiment and found that the device "WDTVlive" is available only if the TV and the device are turned on. With ubuntu I had access to the device independent of the TV. In Kubuntu, If the device is on and the TV off I get: "The file or folder smb://wdtvlive/does not exist". I can only assume that in Ubuntu the device was configured in the network connection directly and on Kubuntu it is configured in Samba which if I understand correctly is a network software destined to access Windows computer.

Image of both networks: Ubuntu Top and kubuntu Bottom

[oshunluvr]

Well, obviously if Ubuntu connects to the device then Kubuntu can, it's just not doing set up right yet. Kubuntu is Ubuntu with a different desktop.

Also, the above pictures reveal that with Kubuntu you're attempting a SAMBA connection and Ubuntu is not - otherwise we'd see a "Windows Network" icon instead of a hard drive icon. I don't know anything about the WDTVLive but I'm guessing Ubuntu is mounting it as a NFS share or something else. The key will be to figure out how Ubuntu is accessing the device - though what protocol.

First step is to find the IP of the WDTVlive. Open a terminal and type: arp -a

This should list everything on the network. Try it first with the TV off then again with the TV on - curious as to if it will show another connection path.

Once you have the IP, with the TV off, try to find the NFS share. Type this in the terminal: sudo showmount -e xxx.xxx.xxx.xxx

replace the xxx.xxx.xxx.xxx with the IP address of the WDTVlive. Post the results if you get any.

[Liamdale]

The TV on or off the results for the kubuntu computer are the same

On Kubuntu computer:

$ arp -a
? (192.168.0.107) at 00:90:a9:62:84:c8 [ether] on enp0s31f6
dlinkrouter (192.168.0.1) at c8:d3:a3:72:94:06 [ether] on enp0s31f6

On the unbuntu computer

$ arp -a
dlinkrouter (192.168.0.1) at c8:d3:a3:72:94:06 [ether] on eth0
WDTVLive.local (192.168.0.107) at 00:90:a9:62:84:c8 [ether] on eth0

From what I can tell the kubuntu computer sees the Media player device but does not know what it is. "? (192.168.0.107) at 00:90:a9:62:84:c8 [ether] on enp0s31f6"
but on the ubuntu the device is clearly identified. I have an other Media Player on another tv called "WDTVlive1". I turned it on and got another "? (192.168.0.100) at ..."

One Tv is a "Smart" tv which accesses the internet, the other a run of the mill "Dumb" tv

The showmount command is not installed on the kubuntu computer
sudo showmount -e 192.168.0.107
[sudo] password
sudo: showmount: command not found

So How to identify for the Kubuntu the devices. Since Ubuntu does it automatically, it seems to me that some part of the network setup is missing

[wizard10000]

We talked about WDTV Live in another thread recently (I own two of them and just love them).

I think Vinny will back me up on this but rather than using SMB or NFS shares I think the most painless option for sharing to WDTV boxes is to use minidlna or some other DLNA server. The nice thing about WDTV boxes is they'll play darned near anything without transcoding; I do have to convert .avi but I don't see many of those any more.

[oshunluvr]

T
The showmount command is not installed on the kubuntu computer
sudo showmount -e 192.168.0.107
[sudo] password
sudo: showmount: command not found

So install this:

sudo apt install nfs-common

and try showmount again. Also try it on the Ubuntu computer.

[Liamdale]

nfs-common was installed but didn't work. I installed apt-file search but I couldn't understand the readout, so I uninstalled (using synaptic) and reinstalled it.

The result is:
$ sudo showmount -e 192.168.0.107
clnt_create: RPC: Port mapper failure - Unable to receive: errno 0 (Success)

[oshunluvr]

Probably not nfs then. Try

smbclient -L 192.168.0.107

[vinnywright]

We talked about WDTV Live in another thread recently (I own two of them and just love them).

I think Vinny will back me up on this but rather than using SMB or NFS shares I think the most painless option for sharing to WDTV boxes is to use minidlna or some other DLNA server. The nice thing about WDTV boxes is they'll play darned near anything without transcoding; I do have to convert .avi but I don't see many of those any more.

yes I will ,,,minidlna is a nice simple media sever ,,,,,,,edit one file and it serves up the files on the box it is running on.

I am still not clear what the OP is trying to do however ,,,,,feed/streem media to the WDTV box ,,,or get stuff from it ,,,,,or transfer to it .

VINNY

[Liamdale]

Did as asked. smbclient was not installed so I installed it

$ smbclient -L 192.168.0.107
WARNING: The "syslog" option is deprecated
Enter liamdale's password:
Domain=[WORKGROUP] OS=[Unix] Server=[Samba 3.5.6]
Server requested LANMAN password (share-level security) but 'client lanman auth = no' or 'client ntlmv2 auth = yes'
tree connect failed: NT_STATUS_ACCESS_DENIED

If I read this right, my owner password did not work for one aspect of command result. I don't have any other password.

To answer vinnywright and wizard10000, access to the media player's hard disk is only to add or remove content directly, without removing the hard disk from the device. I have two such devices. What is minidlna?