PPPoE¶
Point-to-Point Protocol over Ethernet (PPPoE) is a WAN encapsulation method used by some ISPs — particularly for DSL and fibre broadband services — to authenticate subscribers and establish a routed session. The ISP provides a username and password which the router uses to authenticate against the provider's access concentrator (BRAS/NAS) before a public IP address is assigned.
PPPoE is configured directly on the WAN interface rather than as a separate interface type. Once the session is established, the operating system creates a virtual PPP interface (ppp0, ppp1, etc.) which carries the actual traffic.
Note
Some ISPs require PPPoE to be configured on a VLAN sub-interface rather than the physical port. In this case, first create a VLAN interface on the WAN port, then configure PPPoE on that VLAN interface. See VLAN Interface for details.
GUI Configuration¶
Navigate to Device Settings → Network → Interfaces, click on the WAN interface (typically eth0 or a VLAN sub-interface), and set IPv4 Address to PPPoE Username/Password.
Settings¶
| Field | Description |
|---|---|
| Ethernet Interface Name | The physical or VLAN interface connected to the ISP modem (e.g., eth0) |
| Admin Status | Enable or disable this interface |
| IPv4 Address | Set to PPPoE Username/Password to activate PPPoE mode |
| PPPoE Username | Username provided by the ISP for authentication |
| PPPoE Password | Password provided by the ISP for authentication |
| Ignore Default Route | Do not install the ISP-assigned default route into the routing table. Enable this when PPPoE is one of multiple WAN links managed by Multi-WAN — the Multi-WAN engine handles routing instead. |
Other Settings:
| Option | Description |
|---|---|
| DynDNS | Enable Dynamic DNS updates using the PPPoE-assigned IP |
| Enable Tracking | Enable link tracking on this interface for failover detection |
| Link Speed/Duplex | Override physical link speed and duplex settings |
| MTU | PPPoE adds an 8-byte header overhead to each frame. The effective payload MTU is reduced to 1492 bytes (1500 − 8). Set this to 1492 if the ISP does not handle MSS clamping. |
| Proxy ARP | Enable Proxy ARP on this interface |
| Bridge | Bridge this interface to another interface |
| VRRP (High Availability) | Configure VRRP for gateway redundancy |
| Route Metric | Administrative metric for the default route via this PPPoE session. Use this to set priority when multiple WAN links are present. |
| Netflow Export | Enable NetFlow traffic export on this interface |
| VRF | Assign to a VRF instance |
CLI Configuration¶
PPPoE is configured under the physical ethernet interface connected to the ISP modem:
Basic PPPoE setup¶
PPPoE with firewall rules¶
For a single-WAN setup, include outbound NAT and access rules referencing the virtual ppp0 interface:
interface eth0
enable
pppoe 101500223 20160205665
firewall-access 11 permit outbound ppp0
firewall-snat 11 overload outbound ppp0
PPPoE over a VLAN interface¶
When the ISP requires a tagged VLAN on the WAN port:
Set DNS servers explicitly¶
By default, mbox does not use DNS servers pushed by the ISP over PPPoE. Configure DNS explicitly:
Multi-WAN with PPPoE¶
When PPPoE is one of multiple WAN links, omit the default command and manage routing via the Multi-WAN engine. MWAN configuration is applied under the virtual ppp interface:
interface eth0
enable
pppoe <username> <password>
interface ppp0
mwan-group 0
track 8.8.8.8
metric 2
weight 1
Use ppp0 (or ppp1 for a second PPPoE session) as the nexthop interface name in MWAN and routing rules.
Verification¶
Example output:
Displays the active PPPoE session, authentication state, assigned IP, and session uptime.