Enable IPv6
0.25pre [8bf5157] allows users the option of connecting to MythTV via IPv6
Contents |
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 #Prerequsites.
Stop all frontends and backends.
Using mythtv-setup go to the General page, enter the
address of choice in the Local Backend IP address: and in the
Master Backend IP address: fields.
The fields should look like this.
Local Backend IP address: fe01:a:b:1::123 Master Backend IP address: fe01:a:b:1::123
Note that addresses aren't enclosed in brackets ([]) nor is there
a trailing percent sign with a Scope ID (%eth0.)
Use mythtv-setup to configure any slave
backends with their own IPv6 addresses.
Restart the backend(s). Frontends will connect to them via IPv6 as they're restarted.
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.
A #ULA creation script is at the end of this Wiki.
Details on constructing ULAs can be found in RFC 4193.
MythTV must have a Global (e.g. 2001:db8::1) address configured only if it is necessary to run MythTV from a frontend/slave located outside of the Master Backend's LAN.
Site Local (fec0::/10) addresses were deprecated in 2004.
Host (::1) and Link Local (fe80::/64) addresses are not routable and shouldn't be used.
To list currently assigned IPv6 addresses, type:
ifconfig ethX | grep inet6
inet6 addr: fe80::222:22ff:fe22:2222/64 Scope:Link inet6 addr: fe01:a:b:1::123/64 Scope:Site inet6 addr: 2001:db8::123/64 Scope:Global
In the above, the middle 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 fe01:a:b:1::123 masterbe.local masterbe 2001:db8::123 masterbe.local masterbe
Back to #IPv6 Configuration
Prerequsites
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 ls -l /bin/ls done
If the test works for all frontends and slave backends, the system is ready for conversion.
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. Type:
sysctl -a | grep ipv6
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
- If:
net.ipv6.bindv6only = 1
and IPv6 is active and the MythTV system is sill using IPv4 addresses, they will fail to connect until they are converted to use IPv6 addresses, as IPv4 addresses won't be able to connect to the backend (#9820, #9840 and #10165.)
Some distributions keep these options: /etc/sysctl.d.
If there are no files with the value(s) that need to be changed, create a file like 60-bindv6only.conf for example, and put net.ipv6.bindv6only = 0 in it.
- 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.
If there are entries in /etc/hosts (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.
/etc/gai.conf may exist and control this.
Back to #IPv6 Configuration
Tools and sample output
These examples are all from a host with mythbackend
running and using IPv6. MySQL is running and using IPv4.
Obviously, they can be run on frontends and slave backends.
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.
To make sure mythbackend and mysqld
are listening for connections:
sudo netstat -pant | egrep '3306|6543'
When the backend is running, but no frontends are connected, expect:
tcp 0 0 0.0.0.0:3306 0.0.0.0:* LISTEN 1436/mysqld tcp6 0 0 :::6543 :::* LISTEN 2123/mythbackend
With a frontend connected, expect:
tcp 0 0 0.0.0.0:3306 0.0.0.0:* LISTEN 1436/mysqld tcp 0 0 192.168.1.123:3306 192.168.1.200:33878 ESTABLISHED 1436/mysqld ... tcp6 0 0 :::6543 :::* LISTEN 2123/mythbackend tcp6 0 0 fe01:a:b:1::123:6543 fe01:a:b:1::456:35220 ESTABLISHED 2123/mythbackend tcp6 0 0 fe01:a:b:1::123:6543 fe01:a:b:1::456:35219 ESTABLISHED 2123/mythbackend
If installed, nmap may help diagnose the reason
that a connection fails. For example, a firewall
could be blocking access.
nmap -P0 -p 3306,6543 -6 --reason someHostName
The expected response is:
PORT STATE SERVICE REASON 3306/tcp closed mysql conn-refused 6543/tcp open mythtv syn-ack
Port 3306 fails in this test, as expected, because the MySQL version
doesn't support IPv6 (remove the -6 flag above and this will work.)
As always, both mythbackend and mythfrontend
can be started with additional logging enabled:
<code>mythbackend --verbose general,network --nodblog --quiet \
--logpath=/var/log/mythtv --loglevel=debug</code>
A currently running backend's logging can be changed with:
mythbackend --setverbose network --quiet --nodblog
Back to #IPv6 Configuration
ULA creation script
Useful only if IPv6 is active on the host running this script.
This isn't a perfect version of the requirements in RFC 4193 (needs acceses to 64 bit NTP time.)
Adjust myInterface and myNetwork
to suit local needs.
Add interface IDs to its output. For example,
fe01:a:b:1:<add local interface ID here> would become
fe01:a:b:1::123 and
fe01:a:b:1::456 for the hosts used throughout this Wiki.
python-qt4 may need to installed first.
#!/usr/bin/env python
from PyQt4 import QtNetwork
import hashlib, time
myInterface = 'eth0'
mySubnet = '1'
interface = QtNetwork.QNetworkInterface.interfaceFromName(myInterface)
for ipaddress in interface.addressEntries():
if ipaddress.ip().toString().startsWith('FE80:'):
eui64plus = ipaddress.ip().toString()
break
key = '%s %s' % (time.time(), eui64plus)
sha1 = hashlib.sha512(key).hexdigest()
print 'ULA = fe{}:{}:{}:{}:<add local interface ID here>' \
.format(sha1[118:120], sha1[120:124], sha1[124:128], mySubnet)
