Half bridge or full bridge


I'm using openwrt for my router and my ISP give me 8 static public IP.
Now, I have login (user and password) and I use protocol PPPoE, my ISP give me side WAN static IP (it's not my public IP) and after login I have 8 static IP public (only 5 IP I can use).
My router is my gataway and I think my configuration is "half bridge", but I want know sure than I'm in half bridge and not in full bridge.
My country is Italy.

Sorry, what does it mean 'half bridge' and 'full bridge' for PPPoE?

I read here:

Protocol pppoE

If the PPPoE interface is on OpenWrt, then it is full. Otherwise it is half.
In your case the PPPoE is on the ISP router, if I understand properly from your post. Correct?

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I'm using Netgear DM200:

I'm in Full Bridge, is it right?

I wouldn't call it bridge at all. You are in router mode.



My DM200 is my gateway and my LAN is in bridge mode

Are you sure I'm in router mode?

Totally sure. Lan is in bridge to have both the ethernet port and the wifi in the same broadcast domain.

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ok, but Netgear DM 200 hasn't WIFI, it has only ethernet port and dsl port.

I think the confusion stems from the fact OpenWrt sets up a bridge by default for the LAN (which on a router often covers multiple Ethernet ports). The DM200 apparently just has a single LAN port.

As you can see in LuCI it just says 'eth0' and not 'br-lan' so there is no bridge interface. Although the instruction to bridge interfaces (if present) is ticked, which is what you see up top.

So you're using your device as a router (well, a modem/router combination) and I'm pretty sure anything behind your LAN port is getting 192.168.1.x IPs handed out by OpenWrt's DHCP server.



yes, I think my confusion is because I have public static IP and my LAN IP is my gateway (public), back Netgear DM200 I have my router (pfsense) where I set my public IP (I'm using virtual ip function) in this way my Netgear DM200 for me is only a modem has not route functions.
Thank you for help me understand my configuration.

SSH into your DM200 and look at the ip -4 a s output. That will show you all interfaces with their IPv4 addresses. You'll know quickly enough if eth0 has a WAN or LAN IP.

my output:

root@DM200:~# ip -4 a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1000
    inet scope host lo
       valid_lft forever preferred_lft forever
3: br-lan: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP qlen 1000
    inet xxx.x.xxx.xx/29 brd xxx.x.xxx.xx scope global br-lan
       valid_lft forever preferred_lft forever
7: pppoe-wan: <POINTOPOINT,MULTICAST,NOARP,UP,LOWER_UP> mtu 1492 qdisc fq_codel state UNKNOWN qlen 3
    inet yyy.yy.yy.yyy peer scope global pppoe-wan
       valid_lft forever preferred_lft forever

I replace my IP with "x" and ISP IP with "y"

Good that you redacted your WAN IP, but if br-lan is firewalled, then it doesn't matter whether you hide it or not, it only denies us the answer to the question I asked.

You're not exposing anything by sharing LAN IPs, MAC addresses and your WAN IP, yes, that's sensitive information. The IPv4 LAN pools are finite and rather small, so everyone is using the same ones at some point. Little use in redacting them.

Dear Borromini,

my LAN IP is public (my gateway)

When the ISP allows multiple public IPs on an account I think you would create multiple pppoe interfaces to claim them.

Note this doesn't give you any faster line speed but you could have several web servers operating with different names and IPs for example.

True public IPv4s are very scarce these days so most ISPs want a lot of money to hold more than one open for a customer.


my line is FTTC 100/20 Mb/s and 8 IPv4 (only 5 IP I can use for my services other 3 are: gateway, network and broadcast) price € 60 per month.
I'm sure my IP are public and I'm sure I have one only pppoe interface.
My ISP has not physical line it resells and I think my pppoe connection there is for my ISP (it can control traffic and connectios this is normal)
My initial post I want understand how my line works, I think without reseller I'm in full bridge don't need pppoe interface.

p.s my country is Italy

So you are part of a /29 block, which has 8 IP addresses. The first one in the block is the network, and the last one is broadcast -- both of those are reserved and can't be assigned to a machine. The Gateway is their router which is your next hop to reach the Internet. Then there is your IP, and four more, which are likely to be other customers sharing the same gateway. Have you tried pinging them? The gateway should always ping, this is a good way to test your line without counting on the rest of the Internet.

FYI: If you have public IPs at LAN side, disable WAN's Masquerading in Network-Firewall

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my router Netgear DM 200 (openwrt) is gateway has public IP and I have again 5 IP public I can use for my service. Total IP (6) = gateway + 5 IP for services, my gateway is public and possible ping.
My line and my services work wery well I want only understand how my line works.