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Confconsole - Networking

Contents

Overview

Networking allows the user to allocate a server IP address via DHCP (default) or set a static IPv6 or IPv4 address. The IPv6 and IPv4 settings of an adapter are independent: changing one leaves the other as it is.

IMPORTANT: setting a static IP address on a cloud instance (e.g. AWS EC2) will break your server's internet access and may make it unreachable. unless you know exactly what you are doing; DO NOT ADJUST NETWORKING ON CLOUD SERVERS! You have been warned!

As of Confconsole v2.0.0 (default in v16.0+ TurnKey appliances), all cloud builds have Confconsole's Networking options disabled (networking false in /etc/confconsole/confconsole.conf).

./images/02_confconsole_core_networking.png

DHCP

Selecting DHCP from the menu will querry the local DHCP server for a new dynamically allocated IP address.

Static

As noted above; DO NOT change network settings on a cloud server!

Selecting StaticIP from the menu allows you to set a static IP address as follows:

  • IP Adress: The desired static IP address
  • Netmask: Subnet details (if you are on a LAN with 192.168.x.x then it's probably 255.255.255.0)
  • Default Gateway: The internet Gateway IP address (your router IP if on a LAN)
  • Name Server(s): The IP address(es) of DNS servers to use. Currently allows up to 3.

Static IPv6

Selecting StaticIPv6 from the menu sets a static IPv6 address on the adapter and leaves the IPv4 configuration untouched:

  • IPv6 Address/Prefix: address and prefix length in one field, for example 2001:db8:1::10/64. The prefix length is required; there is no netmask field for IPv6.
  • IPv6 Gateway: optional. A link-local gateway such as fe80::1 is accepted (the usual case on a routed segment).
  • Name Server(s): IPv6 addresses of DNS servers, for example 2001:db8::53. IPv4 entries are dropped from the IPv6 stanza; set them in the StaticIP form instead.

An IPv4 address typed in any of these fields is refused with a message pointing at the StaticIP form. Clearing every field and applying returns the adapter to the shipped default, inet6 dhcp (SLAAC and DHCPv6).

The result is an iface eth0 inet6 static stanza in /etc/network/interfaces, next to the existing inet stanza; the # UNCONFIGURED INTERFACES header is kept so Confconsole can edit the file again later. The adapter list and the usage screen show the global IPv6 address, so an adapter with only an IPv6 address is not reported as "not configured".

Usage screen

The main screen lists the addresses of the default adapter and the services reachable on them, IPv6 first. The text comes from the template /etc/confconsole/services.txt (conf/services.txt in the source), with these placeholders:

  • $ipaddr6: the global IPv6 address of the adapter. When the adapter has several, the stable one is chosen: a static address before a SLAAC or DHCPv6 (dynamic) one, and privacy (temporary) addresses last.
  • $ipaddr: the IPv4 address, or the output of publicip_cmd from confconsole.conf when that is set.
  • $hostname and $appname: the host name in capitals and the appliance name from /etc/appname.

A line whose placeholder has no value is dropped, so a template that lists both families shows only the IPv6 block on an IPv6-only adapter and only the IPv4 block on an IPv4-only one. The shipped template is:

Web:       http://[$ipaddr6]
           https://[$ipaddr6]
Web shell: https://[$ipaddr6]:12320
Webmin:    https://[$ipaddr6]:12321
SSH/SFTP:  root@$ipaddr6 (port 22)

Web:       http://$ipaddr
           https://$ipaddr
Web shell: https://$ipaddr:12320
Webmin:    https://$ipaddr:12321
SSH/SFTP:  root@$ipaddr (port 22)

An IPv6 address used as the host of a URL (right after ://) is rendered in brackets, https://[2001:db8:1::10]:12321, whether or not the template writes them; root@$ipaddr6 stays as it is.

Appliance templates written before $ipaddr6 existed, with $ipaddr only, keep working without a change: on an adapter without IPv4 the IPv6 address takes the place of $ipaddr (bracketed in URLs), and on a dual stack adapter two lines, IPv6 Web and IPv6 SSH, precede the template text. To show every service on both families, add the $ipaddr6 lines to the appliance's services.txt as above.

In the networking menu the summary line of an adapter follows the same order: 2001:db8:1::10, 192.0.2.10 (dhcp) [*], with the configuration method after each address when the two families differ (2001:db8:1::10 (static), 192.0.2.10 (dhcp)). [*] marks the adapter the usage screen shows.

Notes

By default, initially TurnKey Linux sets an IP address via DHCP (see limitations below).

Changes to network config via Confconsole are persistent and will survive reboot (see limitations below).

Limitations

IPv6 support covers a static address, DHCP (SLAAC and DHCPv6) and display. Name servers on the IPv6 stanza are limited to IPv6 addresses.

In most build types, by default TurnKey Linux sets an IP address via DHCP. The exceptions to that are Proxmox/LXC and Docker. Generally these builds have an IP (static or dynamic), set via the host when initially created.

In some limited cases (e.g. Proxmox - depending on configuration), any networking adjustments made via Confconsole (or other means) will apply, but will NOT be persistent post-reboot. The networking can still be reconfigured on the running system. However, changes will be lost on reboot. As a general rule, it is recommended that unless you have a need to reconfigure networking within the instance, set the desired configuration on the host.

Some other platforms (e.g. AWS EC2 and OpenStack) will almost certainly break if a static IP is set! As of Confconsole v2.0.0 (default in TurnKey v16.0+) TurnKey Cloud builds (currently includes EC2, Xen and OpenStack) have the Networking config options disabled.

Technical note

Technically the Networking option is not provided by a plugin as it is a legacy "Advanced" menu option.