The WAN of router cannot get IP from BNG Blaster DHCP Server

[simonwa1]

Hello,

I use bngblaster-0.9.23 to test the NAT function of a home router. The Router's WAN port need get IP address from BNG Blaster.

At first, I used network interface. I found "gateway" parameter must be configured. In this situation, there is no gateway (or the gateway will be allocated by DHCP server).
Later, I changed to a10nsp interface. However, the Router's WAN port cannot get IP address.

Does BNG Blaster support this scenario? If yes, how to set up the configuration file? Thanks you in advance.

The json configuration file:

{
  "interfaces": {
    "capture-include-streams": true,
    "a10nsp": [
      {
        "__comment__": "DHCP Server",
        "interface": "enp1s0f0"
      }
    ],
    "access": [
      {
        "__comment__": "DHCP Client",
        "interface": "enp1s0f1",
        "type": "ipoe",
        "ipv6": false,
        "stream-group-id": 1
      }
    ]
  },
  "dhcp": {
    "enable": true,
    "broadcast": false
  },
  "session-traffic": {
    "ipv4-pps": 0
  },
  "streams": [
    {
      "stream-group-id": 1,
      "name": "S1",
      "type": "ipv4",
      "direction": "both",
      "priority": 128,
      "length": 256,
      "pps": 1,
      "nat": true,
      "a10nsp-interface": "enp1s0f0"
    }
  ]
}

I added some debug logs in bngblaster codes and find in this scenario: after bngblaster receives the DHCP Discover, the session is NULL in bbl_a10nsp_rx_handler().

session = bbl_session_get(session_id);

[GIC-de]

This use case wasn’t originally considered, but it might work if you configure your home router to send traffic with a VLAN tag, since A10NSP interfaces are by definition never untagged.

[simonwa1]

This use case wasn’t originally considered, but it might work if you configure your home router to send traffic with a VLAN tag, since A10NSP interfaces are by definition never untagged.

Add a VLAN on WAN interface. The DHCP Discover has a VLAN tag. The Router WAN still cannot get IP address. The session is NULL in bbl_a10nsp_rx_handler(), too.

Perhaps, I can use following topo to do test. Add an outside DHCP server to allocate IP address to Router's WAN.

=====================================
I also configure the Router WAN with a static IP address (192.0.2.1 in following example). It works.

{
  "interfaces": {
    "capture-include-streams": true,
    "network": {
        "interface": "enp1s0f0",
        "address": "192.0.2.254/24",
        "gateway": "192.0.2.1"
        },
    "access": [
      {
        "__comment__": "DHCP Client",
        "interface": "enp1s0f1",
        "type": "ipoe",
        "ipv6": false,
        "stream-group-id": 1
      }
    ]
  },
  "dhcp": {
    "enable": true,
    "broadcast": false
  },
  "session-traffic": {
    "ipv4-pps": 0
  },
  "streams": [
    {
      "stream-group-id": 1,
      "name": "S1",
      "type": "ipv4",
      "direction": "both",
      "priority": 128,
      "length": 256,
      "pps": 100,
      "nat":true,
      "network-interface": "enp1s0f0"
    }
  ]
}

[simonwa1]

The topo is not supported now. Possible WA:

1. Set static IP to router's WAN.
2. Add a switch and DHCP server (as mentioned in the reply).
3. Add a real BNG between BNG Blaster and Router.