The diagram of PPPoE process configuration for MikroTik or Cisco

Below you’ll find both:

1. A diagram illustrating the PPPoE connection process, and
2. Example configurations for both MikroTik and Cisco routers to establish a PPPoE client connection.

📊 1. PPPoE Process Diagram (Client to ISP)

+----------------+         +----------------+          +---------------------+
| Home Router    |         | ISP Access     |          | ISP Authentication  |
| (PPPoE Client) |  --->   | Concentrator   |  --->    | Server (Radius/AAA) |
+----------------+         +----------------+          +---------------------+
       |                          |                             |
       |--- PADI (Discovery) ---> |                             |
       |<-- PADO (Offer) --------|                             |
       |--- PADR (Request) ----->|                             |
       |<-- PADS (Session OK) ---|                             |
       |                          |--- Auth (CHAP/PAP) ------->|
       |                          |<-- Auth Success / Fail ----|
       |<----- IP Assigned -------|                             |
       |------ Internet Access -------------------------------->|

Key Phases:

• Discovery (PADI, PADO, PADR, PADS): Establishes communication.
• Authentication: Username/password verified by ISP.
• Session Established: IP is assigned; data flows.

⚙️ 2. PPPoE Configuration Examples

📡 A. MikroTik PPPoE Client Configuration

You can use Winbox, WebFig, or CLI. Here’s a CLI version:

# 1. Add a PPPoE client interface
/interface pppoe-client add \
    name=pppoe-out1 \
    interface=ether1 \
    user=your-username@isp \
    password=your-password \
    use-peer-dns=yes \
    add-default-route=yes \
    disabled=no

Explanation:

• interface=ether1: This is your WAN port connected to the ISP modem or line.
• user / password: Your ISP-provided PPPoE credentials.
• use-peer-dns=yes: Accept DNS from ISP.
• add-default-route=yes: Adds default internet route through PPPoE.

🧠 B. Cisco Router PPPoE Configuration (Dialer Interface)

For Cisco IOS devices, PPPoE requires a Dialer interface:

! 1. Configure Ethernet interface connected to the modem
interface Ethernet0
 no ip address
 pppoe enable
 pppoe-client dial-pool-number 1

! 2. Create a dialer interface
interface Dialer1
 ip address negotiated
 encapsulation ppp
 dialer pool 1
 dialer-group 1
 ppp chap hostname your-username@isp
 ppp chap password your-password
 ppp pap sent-username your-username@isp password your-password
!
ip route 0.0.0.0 0.0.0.0 Dialer1

Explanation:

• pppoe enable: Enables PPPoE client mode on Ethernet.
• dialer pool: Logical link for managing the session.
• ppp chap/pap: Authentication methods.
• ip address negotiated: IP will be assigned by ISP.
• Default route via Dialer1 enables internet access.

The PPPoE process is a crucial mechanism for authenticated internet access used by ISPs around the world. It includes multiple handshake steps (PADI, PADO, PADR, PADS), authentication via PAP or CHAP, and IP address allocation. MikroTik and Cisco routers both support PPPoE with clear configuration paths. MikroTik uses a direct PPPoE client on an interface, while Cisco uses a dialer-based model for session management.