On 2019-02-09, Adam Evans <a...@agileand.me> wrote: > Hi, i'm trying to set up an OpenBSD router (6.4) on a PcEngines APU2D4 with > Intel i210AT nics however I am having difficulties with PPPoE. I can see the > discovery PADI packets going out using tcpdump but do not see any PADO > response so PPPoE times out and retries sending the PADI packets. > > More confusing is my Netgear R7000 running DD-WRT that I want to replace with > the APU handles PPPoE just fine and bizarrely the PADI packets look the same > however the packets from OpenBSD don't get a response but the R7000 does. > > Using tcpdump the PADI message form OpenBSD looks like below: > > 15:21:47.340929 a0:63:91:47:81:07 ff:ff:ff:ff:ff:ff 8100 36: 802.1Q vid 2 > pri 0 PPPoE-Discovery > code Initiation, version 1, type 1, id 0x0000, length 12 > tag Service-Name, length 0 > tag Host-Uniq, length 4 \210\352\235\232 > > From the router running DD-WRT we can see the PADI packet followed by the > response PADO: > > 01:14:57.164338 a0:63:91:47:81:07 > ff:ff:ff:ff:ff:ff, ethertype 802.1Q > (0x8100), length 36: vlan 2, p 0, ethertype PPPoE D, PPPoE PADI > [Service-Name] [Host-Uniq 0x55440000] > > 01:14:57.171736 78:da:6e:de:df:d4 > a0:63:91:47:81:07, ethertype 802.1Q > (0x8100), length 103: vlan 2, p 0, ethertype PPPoE D, PPPoE PADO > [Vendor-Specific "......AVC000030861999"] [Service-Name] [Host-Uniq > 0x55440000] [AC-Name "syd-gls-har-bras24"] [AC-Cookie "po.N?f'......D27"] > > To me, the PADI packets look the same, I even spoofed the MAC on the OpenBSD > box so it looks like the DD-WRT router although this shouldn't be necessary I > just wanted to verify.
Can you get a more complete dump? (e.g. tcpdump -s1500 -X -e -i em0/eth0) Can you get a dump of the PADI from another machine plugged into em0 to check that it actually makes it onto the wire with the expected tag/prio?? > em0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1492 I don't expect it to make a difference this early in the negotiation but em0 should be mtu 1500, you'll run into problems later with 1492. FWIW normally I do the vlan handling in the modem rather than on the router and pppoe setup is usually straightforward, though it should work either way.
