Issues with High Latency on PPPOE Reconnect

jimp

If you kill dpinger and then edit/save/apply the gateway does it come back OK?

Flole

@stephenw10 No, that option is not set. When the states are killed, the SSH Sessions would also drop, and not continue to function afterwards.

stephenw10

Try disabling gateway monitoring for the PPPoE gateway and retesting.

Steve

Flole

@jimp Theres no need to kill it, just wait for a few seconds and its all back to normal like nothing happened.

I am getting an email with this:

15:56:33 MONITOR: GW_WAN has high latency, omitting from routing group Main
8.8.8.8|x.x.x.x|GW_WAN|218.804ms|634.286ms|0.0%|delay
15:56:33 10292MONITOR: GW_WAN is available now, adding to routing group Failover
8.8.8.8|x.x.x.x|GW_WAN|218.804ms|634.286ms|0.0%|delay
15:56:36 MONITOR: GW_WAN has high latency, omitting from routing group Main
8.8.8.8|x.x.x.x|GW_WAN|218.804ms|634.286ms|0.0%|delay
15:56:36 45534MONITOR: GW_WAN is available now, adding to routing group Failover
8.8.8.8|x.x.x.x|GW_WAN|218.804ms|634.286ms|0.0%|delay
15:56:36 MONITOR: GW_WAN has high latency, omitting from routing group Main
8.8.8.8|x.x.x.x|GW_WAN|218.804ms|634.286ms|0.0%|delay
15:56:36 53386MONITOR: GW_WAN is available now, adding to routing group Failover
8.8.8.8|x.x.x.x|GW_WAN|218.804ms|634.286ms|0.0%|delay
15:56:36 MONITOR: GW_WAN has high latency, omitting from routing group Main
8.8.8.8|x.x.x.x|GW_WAN|218.804ms|634.286ms|0.0%|delay
15:56:36 10292MONITOR: GW_WAN is available now, adding to routing group Failover
8.8.8.8|x.x.x.x|GW_WAN|218.804ms|634.286ms|0.0%|delay
15:56:36 MONITOR: GW_WAN has high latency, omitting from routing group Main
8.8.8.8|x.x.x.x|GW_WAN|204.818ms|611.325ms|0.0%|delay
15:56:36 64937MONITOR: GW_WAN is available now, adding to routing group Failover
8.8.8.8|x.x.x.x|GW_WAN|204.818ms|611.325ms|0.0%|delay
15:56:36 MONITOR: GW_WAN has high latency, omitting from routing group Main
8.8.8.8|x.x.x.x|GW_WAN|204.818ms|611.325ms|0.0%|delay
15:56:36 64937MONITOR: GW_WAN is available now, adding to routing group KDG
8.8.8.8|x.x.x.x|GW_WAN|204.818ms|611.325ms|0.0%|delay
15:56:36 MONITOR: GW_WAN has high latency, omitting from routing group Main
8.8.8.8|x.x.x.x|GW_WAN|204.818ms|611.325ms|0.0%|delay
15:56:36 45534MONITOR: GW_WAN is available now, adding to routing group Failover
8.8.8.8|x.x.x.x|GW_WAN|204.818ms|611.325ms|0.0%|delay
15:56:36 MONITOR: GW_WAN has high latency, omitting from routing group Main
8.8.8.8|x.x.x.x|GW_WAN|204.818ms|611.325ms|0.0%|delay
15:56:37 10292MONITOR: GW_WAN is available now, adding to routing group Failover
8.8.8.8|x.x.x.x|GW_WAN|204.818ms|611.325ms|0.0%|delay
15:56:37 MONITOR: GW_WAN has high latency, omitting from routing group Main
8.8.8.8|x.x.x.x|GW_WAN|204.818ms|611.325ms|0.0%|delay
15:56:37 53386MONITOR: GW_WAN is available now, adding to routing group Failover
8.8.8.8|x.x.x.x|GW_WAN|204.818ms|611.325ms|0.0%|delay
15:56:37 MONITOR: GW_WAN has high latency, omitting from routing group Main
8.8.8.8|x.x.x.x|GW_WAN|204.818ms|611.325ms|0.0%|delay
15:56:37 53386MONITOR: GW_WAN is available now, adding to routing group KDG
8.8.8.8|x.x.x.x|GW_WAN|204.818ms|611.325ms|0.0%|delay
15:56:37 MONITOR: GW_WAN has high latency, omitting from routing group Main
8.8.8.8|x.x.x.x|GW_WAN|204.818ms|611.325ms|0.0%|delay
15:56:37 64937MONITOR: GW_WAN is available now, adding to routing group Failover
8.8.8.8|x.x.x.x|GW_WAN|204.818ms|611.325ms|0.0%|delay

Also Network UPS Tools complained about the UPS being unreachable, and a few seconds later it says that its connected again. Pings to the firewall get also lost for a few seconds, and after some time it's all back to normal.

jimp

Killing and restarting dpinger was more about the 100% CPU issue and not the latency. That may be closer to the root cause.

Flole

Dpinger is going back to normal CPU Usage after a few seconds. Also Avahi is using lots of CPU on a reconnect when its enabled.

I disabled the Gateway monitoring and also marked it as permanent down. Dpinger still had a high CPU, as well as Avahi. So i disabled avahi aswell, now I got a high CPU Usage from dhcpd and route for a second during the reconnect, and the issue is still there.

Flole

I just noticed that with avahi disabled it gets a little better. My normal püing to pfsense is 0.2, on a PPPOE reconnect with avahi disabled I am getting 2 pings with 60-100ms. I need avahi to do printer sharing betweem the Server in the DMZ and the printers on the LAN though.

stephenw10

What hardware are you running this on?

Steve

Flole

pciconf -l | grep class=0x020000
em2@pci0:0:25:0:        class=0x020000 card=0x1494103c chip=0x15028086 rev=0x04 hdr=0x00
em0@pci0:1:0:0: class=0x020000 card=0x7044103c chip=0x105e8086 rev=0x06 hdr=0x00
em1@pci0:1:0:1: class=0x020000 card=0x7044103c chip=0x105e8086 rev=0x06 hdr=0x00
re0@pci0:3:0:0: class=0x020000 card=0x012310ec chip=0x816810ec rev=0x06 hdr=0x00

I also tried unplugging that Realtek PCI Express Card from the Switch so it's no longer an active slave in the bonding, but that didn't help. One of the Intel NICs is an onboard NIC, the other 2 a Dual NIC PCI Express card. Please let me know if thats enough information or if I have to open the machine and get the exact model number from the PCI card.

jimp

Do you have any Advanced Configuration options active on the DHCP WAN? Maybe that's the one causing the issue, not PPPoE. See https://redmine.pfsense.org/issues/8507#note-23

Flole

I have tried disabling IPv6 on the PPPOE Link, so that it's no longer using DHCP but that did not help. The IPv4 is aquired over PPPOE, there's nothing else I can configure in there.

stephenw10

Ah, OK so you don't actually have two WAN connections just two gateways, one v4 and one v6?

If that's the case you would expect the dhcp v6 gateway to go down when the parent PPPoE link reconnects.

Earlier I meant what CPU and RAM etc are you running. I was hoping to judge what sort of CPU usage might be expected there.

Steve

Flole

No I do have 2 Internet connections with 2 Gateways each. I'll call them WAN and DSL from now on to make clear which one I mean.

On WAN I have a static IPv4 Configured and I am using DHCP for IPv6.

On DSL I use PPPOE for IPv4 Configuration and DHCP for IPv6.

The CPU is an Intel(R) Core(TM) i3-2120 CPU @ 3.30GHz with 16GB of RAM

stephenw10

Ah OK.
Hmm, I'm not sure if that would apply at all to v6, I don't think it does.

That hardware is clearly more than capable of handling WAN events without a problem. Or should be least.

Disabling gateway monitoring and/or disabling gateway monitor action on each of those could be telling.

Steve

Flole

I've disabled the monitoring action on all Gateways. With Avahi and snort disabled it looks like this after PPPOE is connected:

64 bytes from 192.168.1.1: icmp_seq=715 ttl=64 time=0.225 ms
64 bytes from 192.168.1.1: icmp_seq=716 ttl=64 time=0.236 ms
64 bytes from 192.168.1.1: icmp_seq=717 ttl=64 time=1996 ms
64 bytes from 192.168.1.1: icmp_seq=718 ttl=64 time=973 ms
64 bytes from 192.168.1.1: icmp_seq=719 ttl=64 time=2895 ms
64 bytes from 192.168.1.1: icmp_seq=720 ttl=64 time=1879 ms
64 bytes from 192.168.1.1: icmp_seq=721 ttl=64 time=855 ms
64 bytes from 192.168.1.1: icmp_seq=722 ttl=64 time=32.5 ms
64 bytes from 192.168.1.1: icmp_seq=723 ttl=64 time=0.297 ms
64 bytes from 192.168.1.1: icmp_seq=724 ttl=64 time=0.213 ms
64 bytes from 192.168.1.1: icmp_seq=725 ttl=64 time=0.166 ms
64 bytes from 192.168.1.1: icmp_seq=726 ttl=64 time=2758 ms
64 bytes from 192.168.1.1: icmp_seq=727 ttl=64 time=1734 ms
64 bytes from 192.168.1.1: icmp_seq=728 ttl=64 time=710 ms
64 bytes from 192.168.1.1: icmp_seq=729 ttl=64 time=772 ms
64 bytes from 192.168.1.1: icmp_seq=730 ttl=64 time=1637 ms
64 bytes from 192.168.1.1: icmp_seq=731 ttl=64 time=628 ms
64 bytes from 192.168.1.1: icmp_seq=732 ttl=64 time=0.299 ms
64 bytes from 192.168.1.1: icmp_seq=733 ttl=64 time=0.310 ms
64 bytes from 192.168.1.1: icmp_seq=734 ttl=64 time=0.339 ms

The following lines all have a latency <1ms.

With avahi disabled and snort enabled it looks like this:

64 bytes from 192.168.1.1: icmp_seq=30 ttl=64 time=0.337 ms
64 bytes from 192.168.1.1: icmp_seq=31 ttl=64 time=2198 ms
64 bytes from 192.168.1.1: icmp_seq=32 ttl=64 time=1174 ms
64 bytes from 192.168.1.1: icmp_seq=33 ttl=64 time=151 ms
64 bytes from 192.168.1.1: icmp_seq=34 ttl=64 time=443 ms
64 bytes from 192.168.1.1: icmp_seq=35 ttl=64 time=2097 ms
64 bytes from 192.168.1.1: icmp_seq=36 ttl=64 time=1090 ms
64 bytes from 192.168.1.1: icmp_seq=37 ttl=64 time=66.9 ms
64 bytes from 192.168.1.1: icmp_seq=38 ttl=64 time=0.310 ms
64 bytes from 192.168.1.1: icmp_seq=39 ttl=64 time=0.305 ms
64 bytes from 192.168.1.1: icmp_seq=40 ttl=64 time=2061 ms
64 bytes from 192.168.1.1: icmp_seq=41 ttl=64 time=1037 ms
64 bytes from 192.168.1.1: icmp_seq=42 ttl=64 time=13.8 ms
64 bytes from 192.168.1.1: icmp_seq=43 ttl=64 time=91.6 ms
64 bytes from 192.168.1.1: icmp_seq=44 ttl=64 time=0.270 ms
64 bytes from 192.168.1.1: icmp_seq=45 ttl=64 time=386 ms
64 bytes from 192.168.1.1: icmp_seq=46 ttl=64 time=0.260 ms

The following lines all have a latency <1ms.

It seems like neither one has an effect on this. I would rather assume that this is somehow related to the IPv6 Latency spikes I am experiencing when using DHCPv6 RA functionality, see this thread for the issue description of that. Is there any way of troubleshooting like for example seeing what kernel module uses how much CPU time or something similar?

stephenw10

If you have top -aSH open in the console you should see what processes are using CPU cycles.
Is it just dpinger?
If you actually disable monitoring for all gateways dpinger shouldn't be running at all so that would reveal anything else.

Steve

Flole

Thats interesting..... I re-enabled dpinger as I think it's clearly not the cause.

PID USERNAME   PRI NICE   SIZE    RES STATE   C   TIME    WCPU COMMAND
   12 root       -92    -     0K   336K CPU2    2  57:12  66.62% [intr{irq268: re0}]
   12 root       -92    -     0K   336K RUN     1   5:40  62.03% [intr{swi4: clock (0)}]
    0 root       -92    -     0K   480K *in6_m  0  28:45  50.42% [kernel{em2 que}]
   11 root       155 ki31     0K    64K RUN     2  23.5H  27.08% [idle{idle: cpu2}]
27976 root        34    0  6900K  2464K nanslp  2   0:01  21.58% [dpinger{dpinger}]
   11 root       155 ki31     0K    64K RUN     0  24.3H  18.74% [idle{idle: cpu0}]
    0 root       -92    -     0K   480K CPU0    0  21:12  18.15% [kernel{em1 que}]
29112 root        33    0  6900K  2508K nanslp  2   0:01  17.51% [dpinger{dpinger}]
   11 root       155 ki31     0K    64K RUN     1  24.5H  16.80% [idle{idle: cpu1}]

Is the realtek Interface the one causing the issues? Right now it is connected as part of the LAGG, would disconnecting help, or removing it from the LAGG or can just removing it physically from the machine show if its the cause?

stephenw10

Well if anything is it's probably the Realtek. You should be able to just remove it from the LAGG unless it's causing some terrrible PCI bus issue.

What throughput are you seeing there? Those numbers look high for a 3.3GHz i3.

Steve

Flole

Unplugged the ethernet cable from the realtek and removed it from the LAGG. Thats what I'm seeing:

  PID USERNAME   PRI NICE   SIZE    RES STATE   C   TIME    WCPU COMMAND
    0 root       -92    -     0K   480K *if_la  2  20:48  92.86% [kernel{em0 que}]
   12 root       -92    -     0K   336K CPU1    1   6:14  92.82% [intr{swi4: clock (0)}]
    0 root       -92    -     0K   480K CPU0    0  23:09  92.55% [kernel{em1 que}]
17789 root        34    0  6900K  2456K nanslp  3   0:01  30.08% [dpinger{dpinger}]
22550 root        33    0  6900K  2508K nanslp  3   0:01  28.47% [dpinger{dpinger}]
41010 root        73    0  6216K  2080K *rawcb  3   0:00  18.74% /sbin/route -n get -inet6 default
20069 root        29    0  8948K  2496K nanslp  3   0:00  15.18% [dpinger{dpinger}]

Those top outputs I have captured right after the ping spike once top started refreshing again. Normally it looks like this:

  PID USERNAME   PRI NICE   SIZE    RES STATE   C   TIME    WCPU COMMAND
   11 root       155 ki31     0K    64K CPU1    1  26.5H  96.82% [idle{idle: cpu1}]
   11 root       155 ki31     0K    64K CPU3    3  26.0H  94.34% [idle{idle: cpu3}]
   11 root       155 ki31     0K    64K RUN     2  25.4H  94.21% [idle{idle: cpu2}]
   11 root       155 ki31     0K    64K CPU0    0  26.2H  89.89% [idle{idle: cpu0}]
    0 root       -92    -     0K   480K -       0  26:31   6.14% [kernel{em1 que}]
    0 root       -92    -     0K   480K -       0  32:31   3.60% [kernel{em2 que}]
    0 root       -92    -     0K   480K -       2  21:44   1.36% [kernel{em0 que}]
92981 root        52   20  6968K  2640K wait    3   0:19   0.31% /bin/sh /var/db/rrd/updaterrd.sh

The realtek and Dual Port Intel are PCI Express, the other Intel is the onboard NIC, just if that matters. The traffic is about 100MBit/s constantly in and out, sometimes it goes up to 1 GBit but that's rather an exception.

stephenw10

Hmm, that's crazy high CPU usage for 100Mb throughput on an i3.

Do you somehow have device polling enabled?
Check the output of ifconfig -a.

Or maybe the CPU is running at a fraction of normal speed somehow?
Check sysctl dev.cpu.0.freq

Steve