ATT Uverse RG Bypass (0.2 BTC)
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I see that ATT uses IP-DSL to do the log in. I wonder if there is a way to get Pfsense to do the log in directly.
Unfortunately, no. ATT uses cryptographic certificates installed in the ROM of the RG to authenticate the RG with the ATT network. This allows them to prevent "unauthorized" equipment from being attached to the network. Unless you feel like dumping the contents of the ROM, identifying the cryptographic certificates, uploading them to your PFSense box, and creating a custom authorization script, it's easier to just perform a man-in-the-middle attack on the 802.1X authentication.
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Thanks for your work on this.
https://tradeblock.com/bitcoin/tx/5be26573726e21c9f70d18af1223fb8e307cae6194a656ca294cc4afa99ae767
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Thanks for your work on this.
https://tradeblock.com/bitcoin/tx/5be26573726e21c9f70d18af1223fb8e307cae6194a656ca294cc4afa99ae767
Received. Thanks!
Digging into this a little more, the VLAN netgraph node may provide the "missing link." I'm hoping to be able to test it in the reasonably near future and see if it actually works.
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Hi rajl.
For the past few weeks, I've independently gone down similar avenues to explore a solution to this problem. I considered porting the EAP Proxy script, but that seemed painful. I opted to patch the kernal (if_bridge.c to be specific) to remove the drop on the 802.1X MAC 01:80:c2:00:00:03. That worked, but only for the EAP problem.
After discovering this post (a great start btw!) and reading more about netgraph, I agree that is probably the best approach. I hoping we can get this working using a combination of: ng_ether, ng_etf, ng_vlan, ng_tee and ng_eiface
For the VLAN0 problem, I expect the netgraph to look like something like this:
# em0 - ATT RG # em1 - ONT # em2 - LAN # ngeth0 - "WAN" netgraph creates interface, removes VLAN0 tag from ONT traffic # make eth devices addressable in netgraph # (kernel module may already be loaded for you) kldload ng_ether # from em1, create a vlan peer # connect em1's lower hook to vlan's downstream hook ngctl mkpeer em1: vlan lower downstream # name peer vlan ngctl name em1:lower vlan # connect em1's upper hook to vlan's nomatch hook ngctl connect em1: vlan: upper nomatch # from vlan, create eiface peer (ngeth0) # connect vlan's untagged hook to eiface's ether hook ngctl mkpeer vlan: eiface untagged ether # instruct vlan: to send vlan0 traffic to untagged hook # which gets sent to the eiface ether hook (ngeth0) ngctl msg vlan: addfilter '{ vlan=0 hook="untagged" }'
I've tested in locally in a VM and I think this part is working. However, the problem I'm struggling with now is combining the EAP netgraph solution with the VLAN netgraph solution. I think this is where ng_tee comes into play, but I'm still trying to wrap my head around it.
I think we need to use ng_tee to split out the ng_ether-em1 interface. Then hook up the EAP graph to one side and the VLAN graph to the other. But my head spins trying to keep left, right, right2left and left2right straight. :) The lacking documentation about netgraph doesnt help either. It seems no one talks about netgraph much.
Have you had any progress or success?
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I just wanted to report back that I got this working, but probably not in the sense you were hoping for.
I’m running pfSense in a VM on Proxmox (KVM/QEMU). For now, I’ve opted to let the hypervisor (Linux) do the EAP and VLAN work. (Same method basically) Here is my setup:
Nothing too special configuration was required for my pfSense VM. Here is my config:
balloon: 0 bootdisk: ide0 cores: 2 cpu: host ide0: ssd0:vm-100-disk-1,size=32G memory: 512 name: pfSense net0: virtio=XX:XX:XX:XX:XX:XX,bridge=vmbr0 net1: virtio=XX:XX:XX:XX:XX:XX,bridge=vmbr1 numa: 0 ostype: other serial0: socket sockets: 1 tablet: 0
The net0 (LAN) interface bridges to vmbr0. vmbr0 bridges to physical eth0, which is connected to my switch.
The net1 (WAN) interface bridges to vmbr1. vmbr1 bridges to vlan0. The vlan0 interface is configured off physical eth1, which is connected to the ONT. net1 MAC address also matches my ATT Gateway. Change it in your pfSense WAN interface setting.
/etc/network/interfaces:
# LAN / eth0 # Connect to switch iface eth0 inet manual # ONT / eth1 # Connect to ONT box outside iface eth1 inet manual # RG / eth2 # Connect to ATT Gateway on ONT port iface eth2 inet manual # LAN Bridge / br0 # Bridge main switch to pfSense # IP is Proxmox host auto vmbr0 iface vmbr0 inet static address 192.168.1.2 netmask 255.255.255.0 gateway 192.168.1.1 bridge_ports eth0 bridge_stp off bridge_fd 0 # VLAN0 Bridge / br1 # Bridge vlan tagged WAN to pfSense auto vmbr1 iface vmbr1 inet manual bridge_ports vlan0 bridge_stp off bridge_fd 0 # EAP Bridge / br2 # Bridge ATT Gateway + ONT so EAP/802.1X auth can complete # group_fwd_mask makes sure 802.1X traffic is bridged auto vmbr2 iface vmbr2 inet manual bridge_ports eth1 eth2 bridge_stp off bridge_fd 0 post-up echo 8 > /sys/class/net/vmbr2/bridge/group_fwd_mask
Unfortunately, Proxmox conflicts with the vlan debian package, so you have to configure the vlan interface with the ip command instead of the interface file:
ip link add link eth1 name vlan0 type vlan id 0
And that’s pretty much it. I haven’t nailed down the timings yet from cold boot to online for a fully automated solution. For some reason, the EAP only takes under certain conditions. I have the best luck with the following:
1. Cold boot hypervisor
2. Wait for EAP to authenticate
3. Start vlan0
4. Start pfSense VMIt’s not perfect right now and it will take some more experimenting. But, it feels good to be off their RG!
I’d still be interested in a pure BSD solution though.
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Glad to see someone else exploring this.
I haven't had a chance to test it yet (my wife and toddler will kill me if I cut the internet tinkering on the weekend – toddler cartoons are sacred).
I hadn't thought of using an ng_tee node, but it sounds like a good idea. Basically, you would connect the ng_tee left hook to the ng_eth downstream hook. You would connect the ng_tee right hook to an ng_vlan (for example), which can filter the vlan 0 tagged traffic for you before passing it up the protocol stack. The ng_etf could be connect to the left2right hook of the ng_tee node using the commands I wrote above to filter the eap traffic.
A modified script would look something like this:
ngctl mkpeer em0: tee lower left ngctl name em0:lower T #Connect vlan to virtual interface for vlan0 traffic, ignore all untagged traffic #by failing to connect the vlan to the ether upper hook (reserved for eap filtering) ngctl mkpeer T: vlan right downstream ngctl name T:right vlan ngctl mkpeer vlan: eiface vlan0 ether ngctl msg vlan0: 'addfilter { vlan=0 hook="vlan0" }' #Connect other hook of T node to ng_etf node for eap filtering/proxying #Leave "lan filter" the same because we only care about eap traffic ngctl mkpeer T: etf left2right downstream ngctl name T:left2right waneapfilter ngctl connect waneapfilter: em0: nomatch upper ngctl mkpeer em1: etf lower downstream ngctl name em1:lower laneapfilter ngctl connect laneapfilter: em1: nomatch upper ngctl connect waneapfilter: laneapfilter: eapout eapout ngctl msg waneapfilter: 'setfilter { matchhook="eapout" ethertype=0x888e }' ngctl msg laneapfilter: 'setfilter { matchhook="eapout" ethertype=0x888e }'
This is an untested script and may throw errors or error message, but the underlying principles should work for any brave souls willing to try! ;) Just make sure that you have the ng_etf, ng_vlan, ng_eth, ng_eiface and ng_tee modules loaded.
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Just occurred to me as an alternative that you could use a NetGraph multiplexer node instead of the ng_tee node.
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I did a bit more testing, but no success just yet. (I suspect I need to first try to get this to work on phsyical hardware. Currently trying using a pfSense VM and I'm not seeing packet carry over from Linux hypervisor to the pfSense VM)
Regarding the ng_ether "bug", I did some digging on this. It turns out that this is not a bug necessarily. pfSense actually does a NGM_ETHER_DETACH against interfaces under some circumstanaces.
https://github.com/pfsense/pfsense/blob/9a18ac7af8ae4a4fde8998c18cc7ba7802056477/src/etc/inc/interfaces.inc#L180
I think this was for performance reasons back when netgraph had performance overhead.
Anyways, you think you'd be able to just do a control message of NGM_ETHER_ATTACH, but that doesn't exist in vanilla FreeBSD. Luckily, pfSense integrates some patches to enable NGM_ETHER_ATTACH, but you have to call it from PHP.
https://github.com/pfsense/FreeBSD-ports/blob/e178a5cf520e928efb3c7d896e3d9fcfb41ac7e5/devel/php56-pfSense-module/files/pfSense.c#L3094
This will re-enable the interface as a node in netgraph:
php -r 'pfSense_ngctl_attach(".", "em0");'
Also, for ng_one2many (assuming that's what you mean by multiplexer) I don't think that will work. I initially looked at this too, but it distributes packets in a round-robin fashion so the many's would only see some packets. At least, that's how I interpret the man page.
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ng_one2many is what I was referring to. The man page states that it has several transmission modes, including round-robin and transmit-all. The man page says that the round robin mode is the default, but my experience when playing with it is that transmit-all was the default. In either case, you could easily set the transmission mode to transmit-all to ensure that you get the desired behavior. So it will work and is simpler to work with than ng_tee.
That's great research on the ng_ether issue. It's been holding me up for awhile, forcing me to do my testing on other distributions (e.g., vanilla FreeBSD and OPNSense) and then curse when I couldn't get it working on PFSense. I'll have to see if it works with my scripts on a VM or PFSense. It should, but Murphy's law always strikes me down!
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Doh! Good catch on the ng_one2many transmit-all algorithm. I was looking at an old man page from an earlier version of FreeBSD, which it didnt support transmit-all yet. That's what I get for googling the man pages, instead of reading them in terminal! May give this a shot later… I'll report back if I have any success.
Cheers!
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It worked!! True U-verse bridge mode on pfSense!
[2.4.2-RELEASE][root@pfsense.knox.lan]/root: ngctl list There are 9 total nodes: Name: T Type: tee ID: 00000021 Num hooks: 3 Name: ue0 Type: ether ID: 00000003 Num hooks: 2 Name: vlan0 Type: vlan ID: 00000024 Num hooks: 2 Name: <unnamed>Type: socket ID: 00000006 Num hooks: 0 Name: ngctl96372 Type: socket ID: 00000047 Num hooks: 0 Name: ngeth0 Type: eiface ID: 00000027 Num hooks: 1 Name: waneapfilter Type: etf ID: 0000002a Num hooks: 3 Name: laneapfilter Type: etf ID: 00000031 Num hooks: 3 Name: em0 Type: ether ID: 00000019 Num hooks: 2 [2.4.2-RELEASE][root@pfsense.knox.lan]/root: ifconfig em0 em0: flags=8843 <up,broadcast,running,simplex,multicast>metric 0 mtu 1500 options=40098 <vlan_mtu,vlan_hwtagging,vlan_hwcsum,vlan_hwtso>ether xx:xx:xx:xx:xx:xx hwaddr xx:xx:xx:xx:xx:xx media: Ethernet autoselect (1000baseT <full-duplex>) status: active [2.4.2-RELEASE][root@pfsense.knox.lan]/root: ifconfig ue0 ue0: flags=8843 <up,broadcast,running,simplex,multicast>metric 0 mtu 1500 options=8000b <rxcsum,txcsum,vlan_mtu,linkstate>ether xx:xx:xx:xx:xx:xx hwaddr xx:xx:xx:xx:xx:xx media: Ethernet autoselect (100baseTX <full-duplex>) status: active [2.4.2-RELEASE][root@pfsense.knox.lan]/root: ifconfig ngeth0 ngeth0: flags=8a43 <up,broadcast,running,allmulti,simplex,multicast>metric 0 mtu 1500 options=28 <vlan_mtu,jumbo_mtu>ether xx:xx:xx:xx:xx:xx inet xx.xx.xx.xx netmask 0xfffffc00 broadcast xx.xx.xx.xx media: Ethernet autoselect (1000baseT <full-duplex>) status: active</full-duplex></vlan_mtu,jumbo_mtu></up,broadcast,running,allmulti,simplex,multicast></full-duplex></rxcsum,txcsum,vlan_mtu,linkstate></up,broadcast,running,simplex,multicast></full-duplex></vlan_mtu,vlan_hwtagging,vlan_hwcsum,vlan_hwtso></up,broadcast,running,simplex,multicast></unnamed>
For reference…
em0 is connected to my ONT.
em1 is connected to my LAN
ue0 is connected to my RG (via USB ethernet)
ngeth0 is the VLANed device which is configured as my WAN in pfSenseCommands to get it running (thanks for the help on ng_tee rajl!) ...
# copy and load ng_etf kernel module kldload /boot/kernel/ng_etf.ko # # setup netgraph nodes # # list out netgraph nodes ngctl list # pfSense for some reason detaches ether devices. reattach any missing devices. php -r 'pfSense_ngctl_attach(".", "em0");' # create tee node to split em0 traffic (one for EAP, one for VLAN0) ngctl mkpeer em0: tee lower left # may get a warning ngctl name em0:lower T # create vlan node + eiface ngctl mkpeer T: vlan right downstream ngctl name T:right vlan0 ngctl mkpeer vlan0: eiface vlan0 ether ngctl msg vlan0: 'addfilter { vlan=0 hook="vlan0" }' # create etf and connect to em0 (ONT) ngctl mkpeer T: etf left2right downstream ngctl name T:left2right waneapfilter ngctl connect waneapfilter: em0: nomatch upper # create etf and connect to em1 (RG) ngctl mkpeer ue0: etf lower downstream ngctl name ue0:lower laneapfilter ngctl connect laneapfilter: ue0: nomatch upper # define filters for EAP traffic ngctl msg waneapfilter: 'setfilter { matchhook="eapout" ethertype=0x888e }' ngctl msg laneapfilter: 'setfilter { matchhook="eapout" ethertype=0x888e }' # use filters to bridge EAP traffic ngctl connect waneapfilter: laneapfilter: eapout eapout # change MAC address to match RG (also can be done in pfSense) ifconfig ngeth0 ether xx:xx:xx:xx:xx:xx
There is still worked to be done though to make this perfect though…
1. Explore using ng_one2many to see if that simplifies the netgraph a bit
2. Automate / Harden change so its persistant across reboots (rajl already documented this earlier)
3. Document!And for what it's worth, I'm running this pfSense in a virtual machine via Proxmox (QEMU/KVM). I couldnt get the VLAN0 traffic to bridge across the interface into pfSense, so I ended up doing a PCI passthrough of the NIC device.
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That's awesome!!! My suspicion is that this would run on baremetal just fine (have to test though). So let's say there's a 4th todo - test this to run on baremetal for those of use that don't virtualize! :-) Hopefully, it won't take too much modification.
This should be pretty easy to automate so that it executes across reboots. Just save your commands as a shell script (don't forget the #!/bin/sh at the beginning of the file) and follow the PFSense instructions for executing shell scripts at the end of the boot process.
https://doc.pfsense.org/index.php/Executing_commands_at_boot_time
I read somewhere that ATT will occassionally push firmware updates to the RG, which this setup may have problems with because the RG is being isolated from the ATT network. But that's a bridge to cross when we get there.
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Would it be possible to have ONT go to port A of a switch set to vlan 20
and have port B of that switch also on vlan 20 connect to the RG's ONT port?Would a switch normally process/filter those 802.1x packets in such a setup?
My pfsense vm is in a different area of the house on a different switch and I'm curious if I'll be able to get this working.
Also, is there any practical benefit to doing this? For instance, would it open outgoing tcp port 25 traffic?
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Would it be possible to have ONT go to port A of a switch set to vlan 20
and have port B of that switch also on vlan 20 connect to the RG's ONT port?Would a switch normally process/filter those 802.1x packets in such a setup?
My pfsense vm is in a different area of the house on a different switch and I'm curious if I'll be able to get this working.
Also, is there any practical benefit to doing this? For instance, would it open outgoing tcp port 25 traffic?
I don't know the answer to your question, but I suspect that won't work. The problem is that ONT traffic comes in on VLAN0 and needs to egress on VLAN0. I'm not sure your switch would tag VLAN0 <-> VLAN20 accordingly.
Also, I'm having some duplicate packets in my previous setup. Hoping one2many might solve that. More to come…
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Would it be possible to have ONT go to port A of a switch set to vlan 20
and have port B of that switch also on vlan 20 connect to the RG's ONT port?Would a switch normally process/filter those 802.1x packets in such a setup?
My pfsense vm is in a different area of the house on a different switch and I'm curious if I'll be able to get this working.
Also, is there any practical benefit to doing this? For instance, would it open outgoing tcp port 25 traffic?
I'll try to answer your questions in detail.
First, the switch setup you're describing won't work because your switch would block the traffic for several reasons. First, if the switch would drop the ethernet frames because ATT tags them as vlan0, but you're setting your ports for vlan20. Second, your switch would probably drop all the authentication frames (802.1X) because most (but not all) switches are fully compliant with 802.1D, which requires that switches and bridges not forward 802.1X frames. However, some switches are not standard compliant and will forward the frames anyway.
That said, you could always run a long cable from one of the house to the other to solve the problem.
Regarding your question about practical benefits, the main practical benefit is performance. The RGs tend to have (1) a small state table with a limited number of entries and (2) middling (at best) performance ARM processors that start to choke under load when you start to do "real routing." As an example, get a few good bit-torrents going on a 1-Gig connection and they try to browser the web. Your performance will crawl because the RG's state table is too small to keep track of all of the connections and the RG's processor is unable to process all the connections at line-speed. Bypassing the RG to use your own PFSense box solves both of these problems.
Some older (but still relevant) articles on why you would want to replace consumer grade routers with an x86 router (such as one using PFSense) are below:
https://arstechnica.com/gadgets/2016/01/numbers-dont-lie-its-time-to-build-your-own-router/
https://arstechnica.com/gadgets/2016/09/the-router-rumble-ars-diy-build-faces-better-tests-tougher-competition/ -
I was afraid you were going to say that – I tried it last night and was unsuccessful.
I've got one of those Netgate gs-2440's that I'll use instead of the vm. I'll be able to put it right next to the RG and ONT.
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Going to try this today with my 4 port SuperMicro physical and report back. Had to install FreeBSD 11.1 in a VM to get the kernel module since the link seems to be dead.
UPDATE:
No luck.
I use the crappy switch trick today and swap VLANs and my igb0 is the MAC of the RG. My igb0 (WAN) is connected into my bypass switch on a VLAN with the ONT and the RG is on another VLAN that gets flipped and flopped if the internet goes down.
I tried the script and connected igb0 straight into the ONT and igb3 to the RG removing my bypass switch out of line. I had no luck and the RG would attempt to AUTH the port on the ONT but never went past that.
Here is the script I used:
#igb2 is connected to the ONT #lagg0 is connected to the LAN #igb3 is connected to the RG #ngeth0 is the VLANed device which is configured as my WAN in pfSense # copy and load ng_etf kernel module /sbin/kldload /boot/kernel/ng_etf.ko # # setup netgraph nodes # # list out netgraph nodes /usr/sbin/ngctl list # pfSense for some reason detaches ether devices. reattach any missing devices. php -r 'pfSense_ngctl_attach(".", "igb0");' # create tee node to split ONT traffic (one for EAP, one for VLAN0) /usr/sbin/ngctl mkpeer igb0: tee lower left # may get a warning /usr/sbin/ngctl name igb0:lower T # create vlan node + eiface /usr/sbin/ngctl mkpeer T: vlan right downstream /usr/sbin/ngctl name T:right vlan0 /usr/sbin/ngctl mkpeer vlan0: eiface vlan0 ether /usr/sbin/ngctl msg vlan0: 'addfilter { vlan=0 hook="vlan0" }' # create etf and connect to ONT /usr/sbin/ngctl mkpeer T: etf left2right downstream /usr/sbin/ngctl name T:left2right waneapfilter /usr/sbin/ngctl connect waneapfilter: igb0: nomatch upper # create etf and connect to RG /usr/sbin/ngctl mkpeer igb3: etf lower downstream /usr/sbin/ngctl name igb3:lower laneapfilter /usr/sbin/ngctl connect laneapfilter: igb3: nomatch upper # define filters for EAP traffic /usr/sbin/ngctl msg waneapfilter: 'setfilter { matchhook="eapout" ethertype=0x888e }' /usr/sbin/ngctl msg laneapfilter: 'setfilter { matchhook="eapout" ethertype=0x888e }' # use filters to bridge EAP traffic /usr/sbin/ngctl connect waneapfilter: laneapfilter: eapout eapout # change MAC address to match RG (also can be done in pfSense) ifconfig ngeth0 ether <mac></mac>
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It's hard to say what your exact issue is without more information.
However, the first thing I would do is run some tcpdumps to see what's going on.
You should run tcpdumps on the ONT interface and the RG interface:
tcpdump -ei em0 tcpdump -ei em1
From the RG interface, you should see some EAPOL starts:
MAC (oui Unknown) > MAC (oui Unknown), ethertype EAPOL (0x888e), length 60: EAPOL start (1) v2, len 0
These packets come every so often. I think the RG does some backoff /delay if it doesnt immediately auth correctly. You can always reboot your RG to initiate.
If your netgraph is setup correctly, this EAP start packet from the RG will be bridged onto your ONT interface. Then you should see some more EAP packets from the ONT interface and RG interface as they negotiate 802.1/X EAP authentication.
Once that completes, you should start seeing 802.1Q (tagged as vlan0) traffic on your ONT interface.
I start another tcpdump on my VLAN0 netgraph device to see if netgraph is bridging over the VLAN0 to ngeth0:
tcpdump -ei ngeth0
If I dont see traffic being bridged between ngeth0 and the ONT interface, then netgraph is not setup correctly. At this point, ngeth0 needs to DHCP using the authorized MAC address. You should see an untagged DCHP request on ngeth0 carry over to the ONT interface tagged as VLAN0. Then you should get a DHCP response and you're in business.
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Hey guys,
I'm trying to wrap my head around all of this and how it works.
I believe the network diagram I've created is how things should be wired up.
igb0 (WAN/ONT) needs to have the mac address of the ATT Residential Gateway (RG).
igb2 is connected to the RG and somehow the ONT<->RG authentication magic happens (EAP Proxy?).
igb1 (LAN) goes to switch.Somehow pfsense is not confused by the mac address on igb0 and the mac address of the RG connected to igb2 being the same.
Are ethernet aliases used? (I think pfsense calls them virtual ips?) I.E. igb0 has an alias for vlan0 traffic which I think is just the ONT<->RG traffic, while the regular igb0 has DHCP (or static) internet address assigned?
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From what I've read from the original DSL Reports thread (http://www.dslreports.com/forum/r29903721-AT-T-Residential-Gateway-Bypass-True-bridge-mode)
There are two possible solutions to get the ONT to talk to the RG through something.
One is to set up a bridge between the two interfaces (igb0 and igb2). However, 801.D compliance means that 801.x packets won't pass across, and pfsense's drivers are compliant. One would need to custom compile the drivers to break this compliance.
Two is to use a proxy. However, it seems that the proxy solutions mentioned are incompatible?
I found two proxy solutions. One is written in python:
https://github.com/jaysoffian/eap_proxy
However, Pyrodex mentioned in this thread that it has a linux dependency (PFRING).
As was mentioned by variance in this thread, the other needs to be compiled –
https://github.com/kuwerty/eapolproxy
However, from the DSL thread:I checked out the eapolproxy, and successfully compiled it on my freebsd dev box. After getting some dependencies (libstdc++) onto pfsense, it does start and appears to be passing the EAP traffic from the RG on OPT1 up to the WAN interface where the ONT is, but nothing ever comes back - it just keeps spamming the EAPOL start and logoffs. I will have to keep playing with it, but I feel like the solution is close. It would be good to have some others try this…
Indeed, that person created an issue in github about this, but it looks like the code has been long abandoned.
Rajl then came up with the netgraph solution which, apparently, should be able to bridge the two interfaces in such a way that the 801.x traffic passes across. However pfsense's oddities breaks this a bit.
aus got this working, but must rely on the linux vm host to do part of the work – something the rest of us cannot rely on.
Pyrodex is testing on bare metal. Since pfsense doesn't come with the ng_etf.ko file, he pulled it from a fresh copy of reebsd 11.1.