Configuring OpenWrt to work with Japan Biglobe 10Giga (MAP-E) service

Issue

• I have switched from the Biglobe Hikari 1G package to the Biglobe 10Giga package, but the transition encountered difficulties because IPv4 is no longer supported. It only supports IPv6, and I had to find a way to use MAP-E to enable IPv4 functionality.
• Although I am eager to use other Router OS options like OPNsense or PFSense, they cannot obtain IPv6 from the ISP due to an incompatible prefix.
• OpenWrt is my last resort, but I will try again with OPNsense later.
• I don't want to use the default shell because I want to understand how I configure everything myself. https://github.com/fakemanhk/openwrt-jp-ipoe/tree/main

Configuration

By default, upon booting after installation, three interfaces are preconfigured: lan, wan, and wan6.

1. System > Software: Install the required add-on package map for MAP-E/MAP-T support, you will need to reboot before you can use it.

2. Configure wan interface

config interface 'wan'
  option device 'eth7'
  option proto 'dhcp'

3. Configure wan6 interface

   Enable WAN6 with DHCPv6, firewall setting you probably need to add this to WAN Zone (same as IPv4 WAN) for protection.

   Under DHCP Server > IPv6 Setting, follow these settings:

   • Designated master ON
   • RA-Service: relay mode
   • DHCPv6-Service: relay mode
   • NDP-Proxy: relay mode
   • Learn routes: ON

config interface 'wan6'
	option device 'eth7'
	option proto 'dhcpv6'
	option reqaddress 'try'
	option reqprefix 'auto'
	option norelease '1'

4. Configure LAN interface

In the RA-Service, I use Server mode because I have already received an IPv6-PD from wan6. Therefore, I will assign it directly to the clients.

DHCP Server > IPv6 settings, basically very similar to WAN6 but Designated master OFF

IPv6 RA Settings: Default

5. Before we create the MAP-E interface, the parameter calculation for MAP-E is needed, in reference section I have attached the IETF information but someone has created a page to calculate, you can copy the public IPv6 address from WAN6 interface and use this online MAP-E rule calculator:

• You can get IPv6 プレフィックスかアドレスを入力 from wan6 interface

• Next will be setting up new MAP-E interface, create a new interface and name it (e.g. mape), and fill the parameters using above generated parameters:
  • Protocol: MAP/LW4over6
  • Type: MAP-E
  • BR/DMR/AFTR: [peeraddr]
  • IPv4 prefix: [ipaddr]
  • IPv4 prefix length: [ip4prefixlen]
  • IPv6 prefix: [ip6prefix]
  • IPv6 prefix length: [ip6prefixlen]
  • EA-bit length: [ealen]
  • PSID-bits length: [psidlen]
  • PSID offset: [offset]
  • From advanced settings, make sure it has WAN6 as Tunnel Link, and check the box Use legacy MAP:

Note: Don't forget to add this mape interface to same firewall zone as WAN/WAN6 since this is also part of WAN.

6. All done. More infogmation https://github.com/fakemanhk/openwrt-jp-ipoe/blob/main/README.md