network setup

README.md

an I-240G-U "modem" connects to the main fiber coming into the house

https://www.scribd.com/document/393153219/I-240G-U-manual is a copy of the manual i found online

coming out of it are 2 telephone ports, 4 gibabit ethernet, and 0 coax ports (the 240 in the model#)

it appears to be designed as a self-contained router, but it must not have suited the ISP's needs

1 telephone port and 3 ethernet are disabled, the ethernet wont even get a link LED when connecting

the 1 remaining ethernet port has at least 3 VLAN's on it

• vlan 33 appears to be a backdoor, the ISP router bridges it into the private lan
• vlan 34 is the tv service, with a 10.x.y.z address space, and multicast packets
• vlan 35 is the internet service, dhcp to get a public ip

currently, the ISP router is configured to use pppoe on its "uplink", and the ISP patches cause that to be on vlan 35

the nixos_router is then running a pppoe-server on its uplink (also vlan 35), which its sharing between the modem and ISP router

vlan 34 is then left purely to the ISP router, which handles tv service over it

i have not been able to get vlan 34 and its multicast traffic to work on the nixos router

compile

dot network.dot -Tsvg > network.svg
dot network.dot -Tpng > network.png

network.dot

digraph {
  ISP -> ONT [label="fiber"]
  ONT -> phone [label="regular old analog phone lines"]
  ONT -> switch1 [label="vlan 34+35"]
  switch1 -> isp_router [label="vlan 34"]
  switch1 -> nixos_router [label="vlan 35"]

  nixos_router -> switch2

  switch2 -> dlink_ap
  switch2 -> nas
  switch2 -> c2d
  switch2 -> switch3

  switch3 -> amd
  switch3 -> raspberrypi

  dlink_ap -> laptop [label="wifi"]
  dlink_ap -> cellphone [label="wifi"]
  dlink_ap -> tablet [label="wifi"]
}

network.svg

random bits.md

  systemd.services = {
    network-vlans = {
      description = "network vlan-start";
      before = [ "network-pre.target" ];
      wantedBy = [ "network-pre.target" ];
      unitConfig.ConditionCapability = "CAP_NET_ADMIN";
      serviceConfig.Type = "oneshot";
      serviceConfig.RemainAfterExit = true;
      path = [ pkgs.vlan pkgs.iproute ];
      script = ''
        ip link set ${WANMASTER} address a8:39:44:90:30:3a
        vconfig add ${WANMASTER} 34 || true
        vconfig set_egress_map ${WANMASTER}.34 0 4 || true
        vconfig add ${WANMASTER} 35 || true
        ip link set ${WANMASTER} up
      '';
    };
  };

a custom systemd service to bring up the 2 vlans

iptables -w -t nat -A nixos-nat-post -s 192.168.2.0/24 -o ${WANMASTER}.34 -j MASQUERADE

this was to configure a second NAT on the IPTV uplink, since the OS only supports 1 uplink NAT