[mythtv-users] Web Frontend stopped working yesterday

[James Linder]

> On 9 Mar 2019, at 12:09 am, mythtv-users-request at mythtv.org wrote:
> 
> 
> As my Internet provider again changed my IP and I no longer use a MythTV
> frontend on another computer, I set the backend IP to 127.0.0.1. I made
> also some system upgrades, which did not change MythTV but perhaps some
> libraries used. I don't remember any other intentional changes.
> 
> Frontend works, Web frontend does not:
> 
> Firefox can?t establish a connection to the server at localhost:6544.
> 
> Nmap doesn't show the port 6544:
> 
> --8<---------------cut here---------------start------------->8---
> Starting Nmap 7.70 ( https://nmap.org ) at 2019-03-08 07:28 CET
> Nmap scan report for localhost (127.0.0.1)
> Host is up (0.000092s latency).
> Other addresses for localhost (not scanned): ::1
> Not shown: 994 closed ports
> PORT     STATE SERVICE
> 22/tcp   open  ssh
> 25/tcp   open  smtp
> 80/tcp   open  http
> 631/tcp  open  ipp
> 3306/tcp open  mysql
> 6543/tcp open  mythtv
> --8<---------------cut here---------------end--------------->8---
> 
> An attempt to connect to
> 
> http://localhost:6543/
> 
> just gives the message "Waiting for localhost..."
> 
> MythTV is version 30.0-dmo3 on Debian testing.
> 
> Best regards
> 
> Janusz
> 
> P.S. I notice another probably unrelated problem: backend stopped at
> night for some unknown reason.

There is a delightful TV (BBC) series by Michael Mosley called ‘Trust me I’m a Doctor’.
Likewise. There is much in your question …

Do typical network setup. You do not need a modem firewall unless you have windows machines. (1)

ISP ——— typically phone line —— [Modem router] —— [Backend] —— [Optional front ends] —— [other machines] ——

Select an IP for your network; typically 10.x.y.z or 192.168.x.y (2) (3)

Never change frontend or backend addresses. You may use 127.0.0.1 to talk to the same machine. (4)
EF a frontend / backend /database on the same machine may use 127.0.0.1 to talk to one another.

now:
No matter what your ISP does he cannot affect your myth machines
Noone on the internet can fiddle with your mythtv (5)(6)
IPV6 changes some of the rules

This does not answer why you can’t talk to yourself. I assume that is buried in the info you did not give
How (and why) does your ISP have anything to do with your myth machines (or your network IP)
What firewalls (and why) are you running. Firewalling 127.0.0.1 is frankly daft.






1. The modem firewall’s ONLY purpose is to stop window machines that have been virused calling OUT
   Your modem does NAT and noone on the internet can call into your machines
      Internet routers may not route private IPs eg 10.x.y.z 192.168.x.y (and class B’s
   Even if your router gets hacked, reboot restores all files.

2. Every modem I’ve encountered *can* set their own IP

3. 127.0.0.1 is the loopback address, you cannot use it as a network address.

4. Ofcourse you can and it’s easy but not trivial to deal with

5. You can arrange internet access. A ssh tunnel is a good option
   http://tigger.ws/wiki/index.php5?title=Port_Forward
   but there are password solutions with server options on your modem

6. Now none of your machines (on a trusted network ie you trust everyone) need a firewall (1)


James