PPPoE
PPPoE is a network protocol for encapsulating PPP frames inside Ethernet frames. It appeared in 1999, in the context of the boom of DSL as the solution for tunneling packets over the DSL connection to the ISPs IP network, and from there to the rest of the Internet. A 2005 networking book noted that “Most DSL providers use PPPoE, which provides authentication, encryption, and compression.” Typical use of PPPoE involves leveraging the PPP facilities for authenticating the user with a username and password, predominately via the PAP protocol and less often via CHAP.
Operating Modes
VyOS supports setting up PPPoE in two different ways to a PPPoE internet connection. This is because most ISPs provide a modem that is also a wireless router.
Home Users
In this method, the DSL Modem/Router connects to the ISP for you with your
credentials preprogrammed into the device. This gives you an RFC 1918
address, such as 192.168.1.0/24 by default.
For a simple home network using just the ISP’s equipment, this is usually desirable. But if you want to run VyOS as your firewall and router, this will result in having a double NAT and firewall setup. This results in a few extra layers of complexity, particularly if you use some NAT or tunnel features.
Business Users
In order to have full control and make use of multiple static public IP addresses, your VyOS will have to initiate the PPPoE connection and control it. In order for this method to work, you will have to figure out how to make your DSL Modem/Router switch into a Bridged Mode so it only acts as a DSL Transceiver device to connect between the Ethernet link of your VyOS and the phone cable. Once your DSL Transceiver is in Bridge Mode, you should get no IP address from it. Please make sure you connect to the Ethernet Port 1 if your DSL Transceiver has a switch, as some of them only work this way.
Once you have an Ethernet device connected, i.e. eth0, then you can configure it to open the PPPoE session for you and your DSL Transceiver (Modem/Router) just acts to translate your messages in a way that vDSL/aDSL understands.
Configuration
Common interface configuration
Set a human readable, descriptive alias for this connection. Alias is used by
e.g. the show interfaces command or SNMP based monitoring tools.
Example:
set interfaces pppoe pppoe0 description 'This is an awesome interface running on VyOS'
Disable given <interface>. It will be placed in administratively down
(A/D) state.
Example:
set interfaces pppoe pppoe0 disable
Place interface in given VRF instance.
See also
There is an entire chapter about how to configure a VRF, please check this for additional information.
Example:
set interfaces pppoe pppoe0 vrf red
PPPoE options
Use this command to restrict the PPPoE session on a given access concentrator. Normally, a host sends a PPPoE initiation packet to start the PPPoE discovery process, a number of access concentrators respond with offer packets and the host selects one of the responding access concentrators to serve this session.
This command allows you to select a specific access concentrator when you know the access concentrators <name>.
Use this command to set the username for authenticating with a remote PPPoE endpoint. Authentication is optional from the system’s point of view but most service providers require it.
Use this command to set the password for authenticating with a remote PPPoE endpoint. Authentication is optional from the system’s point of view but most service providers require it.
When set the interface is enabled for “dial-on-demand”.
Use this command to instruct the system to establish a PPPoE connection automatically once traffic passes through the interface. A disabled on-demand connection is established at boot time and remains up. If the link fails for any reason, the link is brought back up immediately.
Enabled on-demand PPPoE connections bring up the link only when traffic needs to pass this link. If the link fails for any reason, the link is brought back up automatically once traffic passes the interface again. If you configure an on-demand PPPoE connection, you must also configure the idle timeout period, after which an idle PPPoE link will be disconnected. A non-zero idle timeout will never disconnect the link after it first came up.
Use this command to specify whether to automatically add a default route pointing to the endpoint of the PPPoE when the link comes up. The default route is only added if no other default route already exists in the system.
default: A default route to the remote endpoint is automatically added when the link comes up (i.e. auto).
auto: A default route is added if no other default route (From any source) already exists.
force: A default route is added after removing all existing default routes.
none: No default route is installed.
Note
In all modes except ‘none’, all default routes using this interface will be removed when the interface is torn down - even manually installed static interface-routes.
Set the MRU to mru. PPPd will ask the peer to send packets of no more than mru bytes. The value of mru must be between 128 and 16384.
A value of 296 works well on very slow links (40 bytes for TCP/IP header + 256 bytes of data).
The default is 1492.
Note
When using the IPv6 protocol, MRU must be at least 1280 bytes.
Use this command to set the idle timeout interval to be used with on-demand PPPoE sessions. When an on-demand connection is established, the link is brought up only when traffic is sent and is disabled when the link is idle for the interval specified.
If this parameter is not set or 0, an on-demand link will not be taken down when it is idle and after the initial establishment of the connection. It will stay up forever.
Use this command to set the IP address of the local endpoint of a PPPoE session. If it is not set it will be negotiated.
Configure MTU on given <interface>. It is the size (in bytes) of the largest ethernet frame sent on this link.
Use this command to not install advertised DNS nameservers into the local system.
Use this command to set the IP address of the remote endpoint of a PPPoE session. If it is not set it will be negotiated.
Use this command to specify a service name by which the local PPPoE interface can select access concentrators to connect with. It will connect to any access concentrator if not set.
Use this command to link the PPPoE connection to a physical interface. Each PPPoE connection must be established over a physical interface. Interfaces can be regular Ethernet interfaces, VIFs or bonding interfaces/VIFs.
IPv6
Use this command to enable acquisition of IPv6 address using stateless autoconfig (SLAAC).
DHCPv6 Prefix Delegation (PD)
VyOS 1.3 (equuleus) supports DHCPv6-PD (RFC 3633). DHCPv6 Prefix Delegation is supported by most ISPs who provide native IPv6 for consumers on fixed networks.
Some ISPs by default only delegate a /64 prefix. To request for a specific prefix size use this option to request for a bigger delegation for this pd <id>. This value is in the range from 32 - 64 so you could request up to a /32 prefix (if your ISP allows this) down to a /64 delegation.
The default value corresponds to 64.
To request a /56 prefix from your ISP use:
set interfaces pppoe pppoe0 dhcpv6-options pd 0 length 56
Specify the interface address used locally on the interfcae where the prefix has been delegated to. ID must be a decimal integer.
It will be combined with the delegated prefix and the sla-id to form a complete interface address. The default is to use the EUI-64 address of the interface.
Example: Delegate a /64 prefix to interface eth8 which will use a local
address on this router of <prefix>::ffff, as the address 65534 will
correspond to ffff in hexadecimal notation.
set interfaces pppoe pppoe0 dhcpv6-options pd 0 interface eth8 address 65534
Specify the identifier value of the site-level aggregator (SLA) on the interface. ID must be a decimal number greater then 0 which fits in the length of SLA IDs (see below).
Example: If ID is 1 and the client is delegated an IPv6 prefix 2001:db8:ffff::/48, dhcp6c will combine the two values into a single IPv6 prefix, 2001:db8:ffff:1::/64, and will configure the prefix on the specified interface.
set interfaces pppoe pppoe0 dhcpv6-options pd 0 interface eth8 sla-id 1
Operation
Show detailed information on given <interface>
vyos@vyos:~$ show interfaces pppoe pppoe0
pppoe0: <POINTOPOINT,MULTICAST,NOARP,UP,LOWER_UP> mtu 1492 qdisc pfifo_fast state UNKNOWN group default qlen 3
link/ppp
inet 192.0.2.1 peer 192.0.2.255/32 scope global pppoe0
valid_lft forever preferred_lft forever
RX: bytes packets errors dropped overrun mcast
7002658233 5064967 0 0 0 0
TX: bytes packets errors dropped carrier collisions
533822843 1620173 0 0 0 0
Displays queue information for a PPPoE interface.
vyos@vyos:~$ show interfaces pppoe pppoe0 queue
qdisc pfifo_fast 0: root refcnt 2 bands 3 priomap 1 2 2 2 1 2 0 0 1 1 1 1 1 1 1 1
Sent 534625359 bytes 1626761 pkt (dropped 62, overlimits 0 requeues 0)
backlog 0b 0p requeues 0
Connect/Disconnect
Test disconnecting given connection-oriented interface. <interface> can be
pppoe0 as the example.
Example
Requirements:
Your ISPs modem is connected to port
eth0of your VyOS box.No VLAN tagging required by your ISP.
You need your PPPoE credentials from your DSL ISP in order to configure this. The usual username is in the form of name@host.net but may vary depending on ISP.
The largest MTU size you can use with DSL is 1492 due to PPPoE overhead. If you are switching from a DHCP based ISP like cable then be aware that things like VPN links may need to have their MTU sizes adjusted to work within this limit.
With the
default-routeoption set toauto, VyOS will only add the default gateway you receive from your DSL ISP to the routing table if you have no other WAN connections. If you wish to use a dual WAN connection, change thedefault-routeoption toforce. You could also install a static interface-route and set thedefault-routeoption tonone.With the
name-serveroption set tonone, VyOS will ignore the nameservers your ISP sends you and thus you can fully rely on the ones you have configured statically.
Note
Syntax has changed from VyOS 1.2 (crux) and it will be automatically migrated during an upgrade.
set interfaces pppoe pppoe0 default-route 'auto'
set interfaces pppoe pppoe0 mtu 1492
set interfaces pppoe pppoe0 authentication user 'userid'
set interfaces pppoe pppoe0 authentication password 'secret'
set interfaces pppoe pppoe0 source-interface 'eth0'
You should add a firewall to your configuration above as well by assigning it to the pppoe0 itself as shown here:
set interfaces pppoe pppoe0 firewall in name NET-IN
set interfaces pppoe pppoe0 firewall local name NET-LOCAL
set interfaces pppoe pppoe0 firewall out name NET-OUT
VLAN Example
Some recent ISPs require you to build the PPPoE connection through a VLAN interface. One of those ISPs is e.g. Deutsche Telekom in Germany. VyOS can easily create a PPPoE session through an encapsulated VLAN interface. The following configuration will run your PPPoE connection through VLAN7 which is the default VLAN for Deutsche Telekom:
set interfaces pppoe pppoe0 default-route 'auto'
set interfaces pppoe pppoe0 mtu 1492
set interfaces pppoe pppoe0 authentication user 'userid'
set interfaces pppoe pppoe0 authentication password 'secret'
set interfaces pppoe pppoe0 source-interface 'eth0.7'
IPv6 DHCPv6-PD Example
The following configuration will assign a /64 prefix out of a /56 delegation to eth0. The IPv6 address assigned to eth0 will be <prefix>::ffff/64. If you do not know the prefix size delegated to you, start with sla-len 0.
set interfaces pppoe pppoe0 authentication user vyos
set interfaces pppoe pppoe0 authentication password vyos
set interfaces pppoe pppoe0 dhcpv6-options pd 0 interface eth0 address '1'
set interfaces pppoe pppoe0 dhcpv6-options pd 0 interface eth0 sla-id '0'
set interfaces pppoe pppoe0 dhcpv6-options pd 0 length '56'
set interfaces pppoe pppoe0 ipv6 address autoconf
set interfaces pppoe pppoe0 source-interface eth1