Difference between revisions of "Enable IPv6"

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(Remove calculator, suggest search, reformat, correct sample addresses (fd not fe))
(Undo revision 58731. after tetesting on: v0.27-alpha-85-g0bcc449)
 
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Line 1: Line 1:
 
[[Category:HOWTO]]
 
[[Category:HOWTO]]
0.25pre {{gitcommit|8bf5157}} allows users the '''option''' of connecting  
+
{{Note box|0.25 allows users the '''option''' of connecting  
to MythTV via IPv6
+
to <code>mythbackend</code> via IPv6.
 +
To be clear, enabling IPv6 isn't required for successful
 +
operation of MythTV.
 +
}}
  
==IPv6 Configuration==
+
This Wiki shows how to activate IPv6. It is
 +
part of significant changes in the way
 +
MythTV binds to sockets which should be
 +
transparent to users.
  
 +
==IPv6 Configuration==
 
Interfaces typically have multiple IPv6 addresses.
 
Interfaces typically have multiple IPv6 addresses.
 
For help picking the right one, see
 
For help picking the right one, see
[[#Which IPv6 address should be used?]].
+
[[#Which IPv6 address should be used?|Which IPv6 address should be used?]].
 +
 
  
 
If IPv6 is known to be working, just complete the following.
 
If IPv6 is known to be working, just complete the following.
Otherwise, see [[#Prerequsites]].
+
Otherwise, see [[#Basics|Basics]].
  
 
Stop all frontends and backends.
 
Stop all frontends and backends.
  
Using <code>mythtv-setup</code> on the Master Backend, go to the General page, enter the
+
Using <code>mythtv-setup</code> on the master backend, go to the General page and enter the
address of choice in the <code>Local Backend IP address:</code> and in the
+
address of choice.
<code>Master Backend IP address:</code> fields.
+
 
 +
The configuration of someone who just upgraded to 0.25 will look like this:
  
The fields should look like this.
 
 
<pre>
 
<pre>
Local Backend IP address: fd01:a:b:1::123
+
Local Backend
Master Backend IP address: fd01:a:b:1::123
+
    IP address:   192.168.1.123
 +
    IPv6 address: ::1
 +
 
 +
Master Backend
 +
    IP address: 192.168.1.123
 
</pre>
 
</pre>
  
Note that addresses aren't enclosed in brackets (<code>[]</code>) nor is there
+
Change it to look like this:
a trailing percent sign and Scope ID (<code>%eth0</code>.)
+
 
 +
<pre>
 +
Local Backend
 +
    IP address:  192.168.1.123
 +
    IPv6 address: fd01:a:b:1::123
 +
 
 +
Master Backend
 +
    IP address: fd01:a:b:1::123
 +
</pre>
 +
 
 +
The existing IPv4 address shouldn't be removed, as some services
 +
still require it.
 +
 
 +
The pre 0.25 convention that requires both Local Backend and Master Backend addresses
 +
to be the same in order for a backend to be considered a master backend still applies.
 +
It has been expanded to allow for the Master Backend address to equal either the
 +
Local IPv4 '''or''' IPv6 Backend address.
 +
 
 +
Some (non MythTV) programs require their IPv6
 +
addresses enclosed in brackets (<code>[]</code>) or the
 +
addition of a trailing percent sign and Zone Index
 +
(e.g. <code>%eth0</code>.) Neither of these should be used
 +
with MythTV.
  
 
Use <code>mythtv-setup</code> to configure any slave
 
Use <code>mythtv-setup</code> to configure any slave
 
backends with their own IPv6 addresses.
 
backends with their own IPv6 addresses.
  
Restart the backend(s). Frontends will connect to them via IPv6
+
Restart the backend(s).
as they're restarted.
+
  
 
==Which IPv6 address should be used?==
 
==Which IPv6 address should be used?==
Line 39: Line 72:
 
within a LAN.
 
within a LAN.
  
[Note that ULAs have bit 8 set and are,
+
Note that even though ULAs are global addresses, no self
therefore, global addresses - no self respecting router
+
respecting router will pass them out on the internet,
will pass these addresses out on the internet.]
+
much like IPv4 Private Network addresses (e.g. 192.168.1.123.)
  
 
Use a search engine and look for: 'Unique Local Address generator'
 
Use a search engine and look for: 'Unique Local Address generator'
to find a site that will create ULAs correctly.
+
to find a site that will create ULAs correctly like
 +
[http://www.sixxs.net/tools/grh/ula/ this], for example.
  
Details on constructing ULAs can be found in
+
For details on constructing ULAs see
 
[http://tools.ietf.org/html/rfc4193#section-3.2.2 RFC 4193].
 
[http://tools.ietf.org/html/rfc4193#section-3.2.2 RFC 4193].
  
MythTV must have a globally routeble (e.g. <code>2001:db8::1</code>) address configured '''only'''
+
MythTV must have a globally routeble IPv6 address (e.g.
if it is necessary to run MythTV from a frontend/slave located outside
+
<code>2001:db8::1</code>) configured '''only''' if it is
of the Master Backend's LAN.
+
necessary to run MythTV from a frontend/slave over the
 +
internet.
  
 
Site Local (<code>fec0::/10</code>) addresses were deprecated in 2004.
 
Site Local (<code>fec0::/10</code>) addresses were deprecated in 2004.
  
Host (::1) and Link Local (<code>fe80::/64</code>) addresses are not
+
Host (::1) addresses are only useful for a stand alone system. Per a comment on #mythtv-users (7/8/2012,)
routable and shouldn't be used.
+
using ::1 will break [[AirTunes/AirPlay]].
 +
 
 +
Since all Link Local addresses have the same prefix
 +
(<code>fe80::/10</code>), they require a Zone Index
 +
(e.g. <code>%eth0</code>) for routing and shouldn't
 +
be used. MythTV will automatically ignore these
 +
addresses.
  
 
To list currently assigned IPv6 addresses, type:
 
To list currently assigned IPv6 addresses, type:
<code>ifconfig ethX | grep inet6</code>
+
<code>ifconfig | grep inet6</code>
 
<pre>
 
<pre>
 +
inet6 addr: ::1/128 Scope:Host
 
inet6 addr: fe80::222:22ff:fe22:2222/64 Scope:Link
 
inet6 addr: fe80::222:22ff:fe22:2222/64 Scope:Link
 
inet6 addr: fd01:a:b:1::123/64 Scope:Global
 
inet6 addr: fd01:a:b:1::123/64 Scope:Global
Line 66: Line 108:
 
</pre>
 
</pre>
  
In the above, the middle address is probably the best choice.
+
In the above, the 3rd address is probably the best choice.
 
It is also probably one that must be assigned manually.
 
It is also probably one that must be assigned manually.
  
Line 81: Line 123:
 
</pre>
 
</pre>
  
Back to [[#IPv6 Configuration]]
+
Back to [[#IPv6 Configuration|IPv6 Configuration]]
  
==Prerequsites==
+
==Basics==
  
 
Verify that IPv6 is active on each MythTV host.
 
Verify that IPv6 is active on each MythTV host.
  
If ssh, for example, is known to work, a simple
+
If <code>ssh</code>, for example, is known to work, a simple
test (run from the Master Backend) is:
+
test (run from the master backend) is:
  
 
<pre>
 
<pre>
 
for HOST in <list all frontend and slave backends here>
 
for HOST in <list all frontend and slave backends here>
do  ssh -6 $HOST ls -l /bin/ls
+
do  ssh -6 $HOST hostname
 
done
 
done
 
</pre>
 
</pre>
  
 
If the test works for all frontends and slave backends,
 
If the test works for all frontends and slave backends,
the system is ready for conversion.
+
IPv6 can be added to MythTV.
  
 
If the above fails, see the following section.
 
If the above fails, see the following section.
  
Back to [[#IPv6 Configuration]]
+
Back to [[#IPv6 Configuration|IPv6 Configuration]]
 
==What if there's a problem==
 
==What if there's a problem==
  
 
*Make sure IPv6 hasn't been disabled either system wide or for the interface MythTV will use. Type:
 
*Make sure IPv6 hasn't been disabled either system wide or for the interface MythTV will use. Type:
  
<code>sysctl -a | grep ipv6</code>
+
<code>sysctl -a 2> /dev/null | grep "ipv6.*disable"</code>
 
<pre>
 
<pre>
 
net.ipv6.conf.all.disable_ipv6 = 0
 
net.ipv6.conf.all.disable_ipv6 = 0
Line 114: Line 156:
 
</pre>
 
</pre>
  
*If:
+
*Some distributions keep these options in files under <code>/etc/sysctl.d</code>.
<pre>
+
net.ipv6.bindv6only = 1
+
</pre>
+
and IPv6 is active and the MythTV system is sill configured with '''IPv4''' addresses, clients will fail to connect until they are converted to use '''IPv6''' addresses, as IPv4 addresses won't be able to connect to the backend ({{Ticket|9820}}, {{Ticket|9840}} and {{Ticket|10165}}.)
+
 
+
*Some distributions keep these options: <code>/etc/sysctl.d</code>. Look for file names like <code>60-bindv6only.conf</code> for example, and put <code>net.ipv6.bindv6only = 0</code> in it.
+
  
 
*Be sure any firewalls have been adjusted to accept the IPv6 addresses being used.
 
*Be sure any firewalls have been adjusted to accept the IPv6 addresses being used.
  
*MySQL connections are currently selected by the information in config.xml and mysql.txt files. Unless a version of MySQL that supports IPv6 is being used, no changes are required.
+
<!--
 +
*MySQL connections are currently selected by the hostname information in config.xml and mysql.txt files. Unless a version of MySQL that supports IPv6 is being used, no changes are required.
  
 
*If there are entries in <code>/etc/hosts</code> (etc.), for both IPv4 and IPv6 addresses that have the same hostname (which is perfectly legal,) make sure the host's preferences pick IPv4 first. <code>/etc/gai.conf</code> may exist and control this.
 
*If there are entries in <code>/etc/hosts</code> (etc.), for both IPv4 and IPv6 addresses that have the same hostname (which is perfectly legal,) make sure the host's preferences pick IPv4 first. <code>/etc/gai.conf</code> may exist and control this.
 +
-->
 +
*If the MythTV configuration is correct, but no IPv6 traffic is seen during, for example recording playback, Master Backend Override may be enabled in <code>mythtv-setup</code> General section and the Master Backend IP address is still set to an IPv4 address.
  
Back to [[#IPv6 Configuration]]
+
*It may take longer for a system to configure addresses on its ethernet interfaces. This could prevent the backend from binding to those addresses and, for example, prevent remote frontend access. Failures like this will show up as critical errors in the backend logs Use tools supplied by the distribution to guarantee interface configuration is complete before starting the backend.
  
==Tools and sample output==
+
Back to [[#IPv6 Configuration|IPv6 Configuration]]
 
+
These examples are all from a host with <code>mythbackend</code>
+
running and using IPv6. MySQL is running and using IPv4.
+
Obviously, they can be run on frontends and slave backends.
+
  
 +
==Tools and sample output==
 
{{Warning box|The output of some tools and in logfiles may expose IPv6 addresses.
 
{{Warning box|The output of some tools and in logfiles may expose IPv6 addresses.
 
Some addresses contain a modified MAC address or globally addressable IPv6 addresses.
 
Some addresses contain a modified MAC address or globally addressable IPv6 addresses.
 
When posting output to a public form, consider camouflaging them.}}
 
When posting output to a public form, consider camouflaging them.}}
 +
 +
Additional IPv6 information is available in the logfiles created by <code>mythbackend</code>
 +
and <code>mythfrontend</code> if the <code>--loglevel debug</code>
 +
option is used.
 +
 +
<pre>
 +
mythbackend --verbose general --nodblog --quiet \
 +
    --logpath /var/log/mythtv --loglevel debug
 +
</pre>
 +
 +
IPv6 addresses in the logs don't follow the
 +
convention that allows consecutive 0:0s to be represented by ::.
 +
So, the address used in this page: <code>fd01:a:b:1::123</code>
 +
will appear as <code>fd01:a:b:1:0:0:0:123</code>.
 +
This is not a problem, only a convention used by the underlying
 +
<code>Qt</code> code.
 +
 +
These examples are all from a host with <code>mythbackend</code>
 +
running and IPv6 configured. MySQL is running and using IPv4.
 +
Obviously, these tools can be run on frontends and slave backends.
  
 
To make sure <code>mythbackend</code> and <code>mysqld</code>
 
To make sure <code>mythbackend</code> and <code>mysqld</code>
 
are listening for connections:
 
are listening for connections:
  
<code>sudo netstat -pant | egrep '3306|6543'</code>
+
<code>sudo netstat -Wpant | egrep '3306|6543'</code>
  
When the backend is running, but no frontends are connected, expect:
+
When the backend is running, but no slave backends/frontends are connected, expect:
 
<pre>
 
<pre>
tcp  0 0  0.0.0.0:3306     0.0.0.0:*     LISTEN      1436/mysqld     
+
tcp  0 0  0.0.0.0:3306           0.0.0.0:*     LISTEN      1198/mysqld     
tcp6  0       0 :::6543          :::*     LISTEN      2123/mythbackend
+
tcp  0  0  192.168.1.123:6543      0.0.0.0:*      LISTEN      26961/mythbackend
 +
tcp  0  0  127.0.0.1:6543          0.0.0.0:*      LISTEN      26961/mythbackend
 +
tcp6  0 0 fd01:a:b:1::123:6543   :::*           LISTEN      26961/mythbackend
 +
tcp6  0  0  ::1:6543                :::*           LISTEN      26961/mythbackend
 
</pre>
 
</pre>
 
+
With one frontend connected and playing a recording, expect:
With a frontend connected, expect:
+
 
<pre>
 
<pre>
tcp  0 0 0.0.0.0:3306           0.0.0.0:*           LISTEN      1436/mysqld     
+
tcp  0 0 0.0.0.0:3306           0.0.0.0:*             LISTEN      1384/mysqld     
tcp  0 0 192.168.1.123:3306     192.168.1.200:33878  ESTABLISHED 1436/mysqld     
+
tcp  0 0 192.168.1.123:6543    0.0.0.0:*              LISTEN     26961/mythbackend
...
+
tcp  0  0 127.0.0.1:6543        0.0.0.0:*              LISTEN      26961/mythbackend
tcp6 0 0 :::6543                 :::*                LISTEN      2123/mythbackend
+
tcp  0  0 192.168.1.123:3306    192.168.1.234:56538    ESTABLISHED 1384/mysqld     
tcp6  0 0 fd01:a:b:1::123:6543 fd01:a:b:1::456:35220  ESTABLISHED 2123/mythbackend
+
tcp  0  0 192.168.1.123:3306    192.168.1.234:56601    ESTABLISHED 1384/mysqld   
tcp6  0 0 fd01:a:b:1::123:6543 fd01:a:b:1::456:35219  ESTABLISHED 2123/mythbackend
+
tcp  0 0 192.168.1.123:6543    192.168.1.234:42760    ESTABLISHED 26961/mythbackend
 +
tcp  0  0 192.168.1.123:6543     192.168.1.234:42761    ESTABLISHED 26961/mythbackend
 +
tcp  0  0 192.168.10.204:3306    192.168.1.234:56532    ESTABLISHED 1384/mysqld   
 +
tcp6  0 0 fd01:a:b:1::123:6543   fd01:a:b:1::456:36345  ESTABLISHED 26961/mythbackend
 +
tcp6  0 0 fd01:a:b:1::123:6543   fd01:a:b:1::456:36346  ESTABLISHED 26961/mythbackend
 +
tcp6  0  0 ::1:6543              :::*                  LISTEN      26961/mythbackend
 
</pre>
 
</pre>
  
Line 165: Line 228:
 
could be blocking access.
 
could be blocking access.
  
<code>nmap -P0 -p 3306,6543 -6 --reason someHostName</code>
+
<code>nmap -P0 -p 6543 -6 --reason someHostName</code>
  
 
The expected response is:
 
The expected response is:
 
<pre>
 
<pre>
 
PORT    STATE SERVICE REASON
 
PORT    STATE SERVICE REASON
3306/tcp closed mysql  conn-refused
 
 
6543/tcp open  mythtv  syn-ack
 
6543/tcp open  mythtv  syn-ack
 
</pre>
 
</pre>
  
Port 3306 fails in this test, as expected, because the MySQL version
+
Back to [[#IPv6 Configuration|IPv6 Configuration]]
doesn't support IPv6 (remove the <code>-6</code> flag above and this will work.)
+
 
+
As always, both <code>mythbackend</code> and <code>mythfrontend</code>
+
can be started with additional logging enabled:
+
 
+
<pre>
+
<code>mythbackend --verbose general,network --nodblog --quiet \
+
    --logpath=/var/log/mythtv --loglevel=debug</code>
+
</pre>
+
 
+
A currently running backend's logging can be changed with:
+
 
+
<code>mythbackend --setverbose network --quiet --nodblog</code>
+
 
+
Back to [[#IPv6 Configuration]]
+

Latest revision as of 02:27, 7 August 2013


Important.png Note: 0.25 allows users the option of connecting to mythbackend via IPv6. To be clear, enabling IPv6 isn't required for successful operation of MythTV.

This Wiki shows how to activate IPv6. It is part of significant changes in the way MythTV binds to sockets which should be transparent to users.

IPv6 Configuration

Interfaces typically have multiple IPv6 addresses. For help picking the right one, see Which IPv6 address should be used?.


If IPv6 is known to be working, just complete the following. Otherwise, see Basics.

Stop all frontends and backends.

Using mythtv-setup on the master backend, go to the General page and enter the address of choice.

The configuration of someone who just upgraded to 0.25 will look like this:

Local Backend
    IP address:   192.168.1.123
    IPv6 address: ::1

Master Backend
    IP address: 192.168.1.123

Change it to look like this:

Local Backend
    IP address:   192.168.1.123
    IPv6 address: fd01:a:b:1::123

Master Backend
    IP address: fd01:a:b:1::123

The existing IPv4 address shouldn't be removed, as some services still require it.

The pre 0.25 convention that requires both Local Backend and Master Backend addresses to be the same in order for a backend to be considered a master backend still applies. It has been expanded to allow for the Master Backend address to equal either the Local IPv4 or IPv6 Backend address.

Some (non MythTV) programs require their IPv6 addresses enclosed in brackets ([]) or the addition of a trailing percent sign and Zone Index (e.g. %eth0.) Neither of these should be used with MythTV.

Use mythtv-setup to configure any slave backends with their own IPv6 addresses.

Restart the backend(s).

Which IPv6 address should be used?

The most likely choice is a Unique Local Address (ULA.) Use ULA's if all access to the backend will be within a LAN.

Note that even though ULAs are global addresses, no self respecting router will pass them out on the internet, much like IPv4 Private Network addresses (e.g. 192.168.1.123.)

Use a search engine and look for: 'Unique Local Address generator' to find a site that will create ULAs correctly like this, for example.

For details on constructing ULAs see RFC 4193.

MythTV must have a globally routeble IPv6 address (e.g. 2001:db8::1) configured only if it is necessary to run MythTV from a frontend/slave over the internet.

Site Local (fec0::/10) addresses were deprecated in 2004.

Host (::1) addresses are only useful for a stand alone system. Per a comment on #mythtv-users (7/8/2012,) using ::1 will break AirTunes/AirPlay.

Since all Link Local addresses have the same prefix (fe80::/10), they require a Zone Index (e.g. %eth0) for routing and shouldn't be used. MythTV will automatically ignore these addresses.

To list currently assigned IPv6 addresses, type: ifconfig | grep inet6

inet6 addr: ::1/128 Scope:Host
inet6 addr: fe80::222:22ff:fe22:2222/64 Scope:Link
inet6 addr: fd01:a:b:1::123/64 Scope:Global
inet6 addr: 2001:db8::123/64 Scope:Global

In the above, the 3rd address is probably the best choice. It is also probably one that must be assigned manually.

If the desired address doesn't exist, use the configuration tool provided with the host's distribution to add it.

Entries in /etc/hosts (DHCP, router etc.) are optional. The following is an example for one host:

192.168.1.123              masterbe.local    masterbe
fd01:a:b:1::123            masterbe.local    masterbe
2001:db8::123              masterbe.local    masterbe

Back to IPv6 Configuration

Basics

Verify that IPv6 is active on each MythTV host.

If ssh, for example, is known to work, a simple test (run from the master backend) is:

for HOST in <list all frontend and slave backends here>
do  ssh -6 $HOST hostname
done

If the test works for all frontends and slave backends, IPv6 can be added to MythTV.

If the above fails, see the following section.

Back to IPv6 Configuration

What if there's a problem

  • Make sure IPv6 hasn't been disabled either system wide or for the interface MythTV will use. Type:

sysctl -a 2> /dev/null | grep "ipv6.*disable"

net.ipv6.conf.all.disable_ipv6 = 0
net.ipv6.conf.default.disable_ipv6 = 0
net.ipv6.conf.lo.disable_ipv6 = 0
net.ipv6.conf.eth0.disable_ipv6 = 0
  • Some distributions keep these options in files under /etc/sysctl.d.
  • Be sure any firewalls have been adjusted to accept the IPv6 addresses being used.
  • If the MythTV configuration is correct, but no IPv6 traffic is seen during, for example recording playback, Master Backend Override may be enabled in mythtv-setup General section and the Master Backend IP address is still set to an IPv4 address.
  • It may take longer for a system to configure addresses on its ethernet interfaces. This could prevent the backend from binding to those addresses and, for example, prevent remote frontend access. Failures like this will show up as critical errors in the backend logs Use tools supplied by the distribution to guarantee interface configuration is complete before starting the backend.

Back to IPv6 Configuration

Tools and sample output

Warning.png Warning: The output of some tools and in logfiles may expose IPv6 addresses. Some addresses contain a modified MAC address or globally addressable IPv6 addresses. When posting output to a public form, consider camouflaging them.

Additional IPv6 information is available in the logfiles created by mythbackend and mythfrontend if the --loglevel debug option is used.

mythbackend --verbose general --nodblog --quiet \
    --logpath /var/log/mythtv --loglevel debug

IPv6 addresses in the logs don't follow the convention that allows consecutive 0:0s to be represented by ::. So, the address used in this page: fd01:a:b:1::123 will appear as fd01:a:b:1:0:0:0:123. This is not a problem, only a convention used by the underlying Qt code.

These examples are all from a host with mythbackend running and IPv6 configured. MySQL is running and using IPv4. Obviously, these tools can be run on frontends and slave backends.

To make sure mythbackend and mysqld are listening for connections:

sudo netstat -Wpant | egrep '3306|6543'

When the backend is running, but no slave backends/frontends are connected, expect:

tcp   0  0  0.0.0.0:3306            0.0.0.0:*      LISTEN      1198/mysqld     
tcp   0  0  192.168.1.123:6543      0.0.0.0:*      LISTEN      26961/mythbackend
tcp   0  0  127.0.0.1:6543          0.0.0.0:*      LISTEN      26961/mythbackend
tcp6  0  0  fd01:a:b:1::123:6543    :::*           LISTEN      26961/mythbackend
tcp6  0  0  ::1:6543                :::*           LISTEN      26961/mythbackend

With one frontend connected and playing a recording, expect:

tcp   0  0 0.0.0.0:3306           0.0.0.0:*              LISTEN      1384/mysqld     
tcp   0  0 192.168.1.123:6543     0.0.0.0:*              LISTEN      26961/mythbackend
tcp   0  0 127.0.0.1:6543         0.0.0.0:*              LISTEN      26961/mythbackend
tcp   0  0 192.168.1.123:3306     192.168.1.234:56538    ESTABLISHED 1384/mysqld     
tcp   0  0 192.168.1.123:3306     192.168.1.234:56601    ESTABLISHED 1384/mysqld     
tcp   0  0 192.168.1.123:6543     192.168.1.234:42760    ESTABLISHED 26961/mythbackend
tcp   0  0 192.168.1.123:6543     192.168.1.234:42761    ESTABLISHED 26961/mythbackend
tcp   0  0 192.168.10.204:3306    192.168.1.234:56532    ESTABLISHED 1384/mysqld     
tcp6  0  0 fd01:a:b:1::123:6543   fd01:a:b:1::456:36345  ESTABLISHED 26961/mythbackend
tcp6  0  0 fd01:a:b:1::123:6543   fd01:a:b:1::456:36346  ESTABLISHED 26961/mythbackend
tcp6  0  0 ::1:6543               :::*                   LISTEN      26961/mythbackend

If installed, nmap may help diagnose the reason that a connection fails. For example, a firewall could be blocking access.

nmap -P0 -p 6543 -6 --reason someHostName

The expected response is:

PORT     STATE SERVICE REASON
6543/tcp open   mythtv  syn-ack

Back to IPv6 Configuration