if_pppoe problems with php-fpm causing loops. (resolved)

stephenw10

Nice debugging. Now why would that be required for your connection....

Can you show the new patch you've ended up using?

chrcoluk

--- /etc/inc/interfaces.inc     2025-05-20 15:25:19.000000000 +0100
+++ /etc/inc/interfaces.inc        2025-07-07 19:48:09.639482000 +0100
@@ -4024,6 +4024,7 @@
         * lock deleted.
         */
 
+        mwexec("/bin/sleep 3");
        if (!file_exists("/tmp/dhcp6c_lock")) {
                kill_dhcp6client_process(true);
                /* Lock it to avoid multiple runs */

Also

# ps ax | grep dhcp6
88258  -  Is      0:00.01 /usr/local/sbin/dhcp6c -d -c /var/etc/dhcp6c.conf -p /var/run/dhcp6c.pid pppoe2
99730  1  S+      0:00.00 grep --color dhcp6

# cat /var/run/dhcp6c.pid 
88258

chrcoluk

ISP is doing LNS maintenance over the upcoming week, so will see how that reconnection goes.

Also I patched mss clamping in the scrub code to make it 52 bytes instead of 40 for timestamps overhead, and wow things have never performed so good, so that combined with this driver is working really well for me now.

stephenw10

Hmm did I miss something about timestamps? What did you discover that required that?

w0w

So, are we talking about RFC 1323 and a modification to /etc/inc/filter.inc?

chrcoluk

I noticed pfSense code if mss clamp is enabled just does the basic 40 bytes (IPv4) 60 bytes (IPv6) so e.g. a 1460 bytes MSS clamp on IPv4 with a 1500 byte MTU, I think it should be 1448 in such a scenario, so I changed the 40 bytes to 52, currently I have only patched the IPv4 code. Timestamps now days is on by default in operating systems and important on high bandwidth.

I did notice youtube videos had a stall before playing, as soon as I made this adjustment that has been fixed, and there is a wider improvement I am noticing as well.

It is a very basic patch as well. Modifying the firewall generation script, scrub rules.

w0w yes to both.

                /* set up MSS clamping */
                if ($mss) {
                        /* different size of IPv4/IPv6 header, https://redmine.pfsense.org/issues/11409 */
-                        $mssclamp4 = "max-mss " . ($mss - 40);
+                        $mssclamp4 = "max-mss " . ($mss - 52);

mssclamp6 is right under that as well.

w0w

@chrcoluk said in if_pppoe problems with php-fpm causing loops. (resolved):

I have only patched the IPv4 code

Why not both stacks?

chrcoluk

@w0w I will do both stacks, it was something I did very quickly and I want to check if its still 12 bytes for ipv6 as well.

Patched it now. So on my 1500 bytes MTU, 1448 MSS for IPV4, 1428 MSS for IPv6.

w0w

@chrcoluk
I did the same and even captured WAN packets to confirm. Looks like it's working — we'll see. By the way, I'm using gigabit PPPoE.

stephenw10

Hmm, interesting. I can't say I've noticed that. But also I wasn't looking for it specifically.

chrcoluk

After some more testing, it looks like if_pppoe resolves an issue related to fragments that existed in the legacy pppoe code.

w0w

@chrcoluk said in if_pppoe problems with php-fpm causing loops. (resolved):

issue related to fragments

What issue?

chrcoluk

@w0w I had a device that had issues with small tcp packets, it still fails on the legacy code but now passes on the new code. I didnt really consider it an issue pppoe side before, but the issue is gone on if_pppoe.

chrcoluk

PPP session was down for a while late afternoon, seen notification from ISP, and then when I got to firewall could just see repeated "received unexpected pad0" on console, and logs looked like was in a loop retrying.

After I confirmed ONT ok, I disabled WAN, enabled it, selected apply and it woke up within seconds.

Now there was external cause for the initial disconnection, was an outage on CityFibre the FTTP local provider, so the issue is it failed to connect automatically rather than the initial disconnection.

stephenw10

Hmm, interesting. Did you try just disconnecting and reconnecting in Status > Interfaces?

ajtuk

I had the same issue today after CityFibre went down. The PPPOE connection does not restart, luckily I can SSH in from the FTTC line and reboot it. Then it works fine. But if the ISP drops the connection, it's either access the GUI and click Connect or reboot.

chrcoluk

There was a second later outage, on the second outage it came back up by itself.

chrcoluk

@stephenw10 I didnt try that as I had experiences recently, using that method could leave services down, whilst toggling in interfaces always seems to keep everything running cleanly.

There is a chance of more drops as AAISP havent closed the incident, given CF are refusing to communicate with them on what has gone wrong, if it gets stuck again, I will try a cycle on the interfaces screen.

chrcoluk

@stephenw10 It went down again, didnt auto recover, status interfaces said it was still up (no ip's), I took it down then back up again and it came back right away.

w0w

@chrcoluk
When the PPPoE interface shows 'up', it means it's in the process of connecting. How long did you wait? Next time look what does

pppcfg pppoe0

show.