Random ping spikes while using Ethernet

pycan · December 29, 2022, 6:04pm

Hello,

I've just recently bought Asus RT-AX53U and flashed OpenWrt on it. I was able to do everything I needed like setting up VLANs for guests and IoT devices.

There is one outstanding issue I have troubles with. It happens on both wired connection via Ethernet and Wifi. The latency randomly spikes to values around 1500ms. This complicates online gaming and video calls a lot.

Since it's happening on wired connection as well, I think the issue is with the router. I've tried SQM but that didn't help at all.

I'm very new to networking so any help would be greatly appreciated. Thank you.

EDIT: I just tried factory reset of OpenWrt, connected as a single host via Ethernet to access Luci and it's happening too. I'm going to revert back to AsusWrt to see if it's happening there too.

moeller0 · December 30, 2022, 9:35am

What application are you using or measuring the RTT?

If you install mtr on your OpenWrt router (opkg update ; opkg install mtr) and run a speedtest against , say 8.8.8.8"

mtr -ezb4 8.8.8.8

this is interactive mode, you can also run it for a predeterimined number of probes, e.g. 100:

mtr -ezb4w -c 100 8.8.8.8

just post the output of the last command to this thread by copy and pasting from the terminal you ran the command in, no need for screenshots of terminal output, after copying select the newly added text and click the preformatted text button "</>".

BTW, according to these results you are nearest to London and Paris but not all that close to these either...

pycan · December 30, 2022, 10:54am

Hey, thanks a lot. I measured it here. Here's the output of the commands you mentioned.

Start: 2022-12-30T11:50:57+0100
HOST: OpenWrt                                                    Loss%   Snt   Last   Avg  Best  Wrst StDev
  1. AS???    ???                                                100.0   100    0.0   0.0   0.0   0.0   0.0
  2. AS16019  ip-86-49-1-65.bb.vodafone.cz (86.49.1.65)           5.0%   100    9.1  10.0   7.0  45.8   5.5
  3. AS???    pzmsc-rc-01-ae30.net.vodafone.cz (185.188.187.28)   3.0%   100    9.6  10.3   8.0  23.3   2.2
       [MPLS: Lbl 1208 TC 0 S u TTL 1]
  4. AS???    strig01-lag-13.net.vodafone.cz (185.188.187.244)   95.0%   100    9.1  10.7   7.9  16.0   3.2
  5. AS16019  te2-2.sitr00i.vodafone.cz (217.77.160.45)          95.0%   100    9.1   9.3   8.7  10.3   0.6
  6. AS16019  cst2-254-1.cust.vodafone.cz (31.30.254.1)          97.0%   100    9.5   9.7   9.5   9.9   0.2
  7. AS15169  142.250.164.176 (142.250.164.176)                   5.0%   100   11.7  13.0   9.8 130.4  12.3
  8. AS15169  172.253.50.253 (172.253.50.253)                     4.0%   100    8.6   9.9   8.1  22.8   2.3
  9. AS15169  142.251.224.123 (142.251.224.123)                   4.0%   100    8.9   9.8   8.2  14.9   1.2
 10. AS15169  dns.google (8.8.8.8)                                3.0%   100    8.2   8.1   6.9  21.8   1.8

moeller0 · December 30, 2022, 11:19am

3% loss is really bad and can easily cause issues, and that level of loss seems to be along your whole path... maybe time to see whether your router show some interface errors for the WAN interface.

pycan · December 30, 2022, 2:15pm

I'm not exactly sure what to look for. I checked the system logs in OpenWrt but haven't found anything suspicious.

The issue seems similar to this one, but I'm using more recent modem Compal CH7465VF. I've tried to change the cable that is connected to WAN port on my router and also tried different port on the modem. No effect.

I didn't have this issue before I had the router (I was using the modem in router mode). I also think the problem wasn't present when I used the Asus router for about a week with AsusWrt. I've tried to go back to it from OpenWrt today to confirm, but wasn't able to (router firmware restoration failed). So it seems I'm stuck with the router running OpenWrt with this issue or I could go back to using ISP modem in router mode again.

moeller0 · December 30, 2022, 2:45pm

Maybe let's start with posting the output of ifconfig here which will show some error counters that likely are zero, but if we would see errors there that could finger the ethernet link to the cable modem.

If I understand correctly, you can get some information about the DOCSIS link (Router >> Cable Modem > Connection) in the compal and post it here, these could as well be errors in the DOCSIS segment...

For testing this would be a good idea....

pycan · December 30, 2022, 6:36pm

Ifconfig result:

br-lan    Link encap:Ethernet  HWaddr 50:EB:F6:82:DB:24
          inet addr:192.168.99.1  Bcast:192.168.99.255  Mask:255.255.255.0
          inet6 addr: fe80::52eb:f6ff:fe82:db24/64 Scope:Link
          inet6 addr: fd09:781b:45a7::1/60 Scope:Global
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:4958 errors:0 dropped:0 overruns:0 frame:0
          TX packets:4530 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:1064418 (1.0 MiB)  TX bytes:6237161 (5.9 MiB)

eth0      Link encap:Ethernet  HWaddr 50:EB:F6:82:DB:24
          inet6 addr: fe80::52eb:f6ff:fe82:db24/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1504  Metric:1
          RX packets:41840 errors:0 dropped:0 overruns:0 frame:0
          TX packets:4849 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:8616434 (8.2 MiB)  TX bytes:1097876 (1.0 MiB)
          Interrupt:21

lan1      Link encap:Ethernet  HWaddr 50:EB:F6:82:DB:24
          UP BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)

lan2      Link encap:Ethernet  HWaddr 50:EB:F6:82:DB:24
          UP BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)

lan3      Link encap:Ethernet  HWaddr 50:EB:F6:82:DB:24
          UP BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)

lo        Link encap:Local Loopback
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:65536  Metric:1
          RX packets:76 errors:0 dropped:0 overruns:0 frame:0
          TX packets:76 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:7807 (7.6 KiB)  TX bytes:7807 (7.6 KiB)

wan       Link encap:Ethernet  HWaddr 50:EB:F6:82:DB:24
          inet addr:89.103.132.89  Bcast:89.103.132.255  Mask:255.255.255.0
          inet6 addr: fe80::52eb:f6ff:fe82:db24/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:41840 errors:0 dropped:0 overruns:0 frame:0
          TX packets:4746 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:7863314 (7.4 MiB)  TX bytes:1050912 (1.0 MiB)

wlan0     Link encap:Ethernet  HWaddr 50:EB:F6:82:DB:24
          inet addr:192.168.3.1  Bcast:192.168.3.255  Mask:255.255.255.0
          inet6 addr: fe80::52eb:f6ff:fe82:db24/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:13 errors:0 dropped:0 overruns:0 frame:0
          TX packets:21 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:3194 (3.1 KiB)  TX bytes:4774 (4.6 KiB)

wlan1     Link encap:Ethernet  HWaddr 50:EB:F6:82:DB:28
          inet6 addr: fe80::52eb:f6ff:fe82:db28/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:5047 errors:0 dropped:0 overruns:0 frame:0
          TX packets:6539 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:1140004 (1.0 MiB)  TX bytes:6412576 (6.1 MiB)

wlan1-1   Link encap:Ethernet  HWaddr 52:EB:F6:82:DB:28
          inet addr:192.168.2.1  Bcast:192.168.2.255  Mask:255.255.255.0
          inet6 addr: fe80::50eb:f6ff:fe82:db28/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:8 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:0 (0.0 B)  TX bytes:1232 (1.2 KiB)

So I run the mtr while connected to ISP modem directly. Results:

HOST:--------------------------                                  Loss%   Snt   Last   Avg  Best  Wrst StDev
  1. AS???    192.168.0.1                                        99.0%   100    6.2   6.2   6.2   6.2   0.0
  2. AS???    ???                                                100.0   100    0.0   0.0   0.0   0.0   0.0
  3. AS16019  ip-86-49-1-65.bb.vodafone.cz (86.49.1.65)           0.0%   100   11.7  14.5  10.7  26.8   3.7
  4. AS???    pzmsc-rc-01-ae30.net.vodafone.cz (185.188.187.28)   0.0%   100   13.7  16.1  11.6 153.1  14.1
       [MPLS: Lbl 1208 TC 0 S u TTL 1]
  5. AS???    strig01-lag-13.net.vodafone.cz (185.188.187.244)   92.0%   100   13.1  14.2  11.9  20.4   2.9
  6. AS16019  te2-2.sitr00i.vodafone.cz (217.77.160.45)          92.0%   100   11.3  12.8  11.3  13.9   0.9
  7. AS16019  cst2-254-1.cust.vodafone.cz (31.30.254.1)          94.0%   100   20.0  15.5  13.0  20.0   3.0
  8. AS15169  142.250.164.176                                     0.0%   100   17.2  16.5  13.0  88.7   8.0
  9. AS15169  172.253.50.255                                      0.0%   100   15.3  16.5  13.7  25.1   2.2
 10. AS15169  142.251.224.129                                     0.0%   100   17.4  14.2  11.8  26.6   2.2
 11. AS15169  dns.google (8.8.8.8)                                0.0%   100   13.0  12.2  10.7  19.3   1.4

Didn't find anything like this in the compal web interface unfortunately.

moeller0 · December 30, 2022, 7:26pm

Damn, no errors (as expected), so the router hardware is not a hot candidate for your problems....

Hmm, the loss seem to be gone... which sort of implies the OpenWrt router again...

I looked at the german manual from vodafone but that might be different in the GUI for the CZ-version?

EDIT: I might have gotten the wrong model, sorry. Maybe try to connect to https://192.168.100.1 which is an address most DOCSIS modems report some information under...

pycan · December 31, 2022, 7:24am

Yeah I checked there but the GUI is really limited with hardly any useful information.

I asked about this issue on Vodafone forum as well and was recommended to try to change the modem piece for piece. I've had it for almost 2 years so maybe the change will help. Apparently, this model had this issue in bridge mode in the past.

I'll post the update here once I know more.

pycan · December 31, 2022, 11:53am

So I did a few more tests today before ordering an exchange of Compal modem. To my surprise, the results are different. There are still a few packets lost on the way, but not at the last hop. Also the web ping testing tool is not showing spikes to 1500ms as it did before. I tried to play an online game to test it and I haven't noticed any lags anymore. Nothing really changed so I have no idea why it's working now.

HOST: OpenWrt                                                    Loss%   Snt   Last   Avg  Best  Wrst StDev
  1. AS???    ???                                                100.0   100    0.0   0.0   0.0   0.0   0.0
  2. AS16019  ip-86-49-1-65.bb.vodafone.cz (86.49.1.65)           1.0%   100    8.4   9.8   6.9  48.9   5.6
  3. AS???    pzmsc-rc-01-ae30.net.vodafone.cz (185.188.187.28)   5.0%   100    9.4  11.3   7.6  84.4   8.1
       [MPLS: Lbl 1208 TC 0 S u TTL 1]
  4. AS???    strig01-lag-13.net.vodafone.cz (185.188.187.244)   89.0%   100    7.5   8.9   7.5  12.0   1.3
  5. AS16019  te2-2.sitr00i.vodafone.cz (217.77.160.45)          89.0%   100    8.1   9.1   8.1  12.0   1.2
  6. AS16019  cst2-254-1.cust.vodafone.cz (31.30.254.1)          90.0%   100    9.0  10.8   8.9  16.5   2.4
  7. AS15169  142.250.164.176 (142.250.164.176)                   2.0%   100   12.7  12.2   9.9  20.2   2.3
  8. AS15169  172.253.50.253 (172.253.50.253)                     4.0%   100   15.6  10.1   8.0  17.2   1.7
  9. AS15169  142.251.224.123 (142.251.224.123)                   2.0%   100    9.6  10.0   7.9  19.1   1.9
 10. AS15169  dns.google (8.8.8.8)                                0.0%   100    8.0   8.5   7.0  16.3   1.8

I'll wait a few more days to see if it stays like this.

moeller0 · December 31, 2022, 1:35pm

Fair enough. It could be transient overload in your segment or some RF-ingress in the segment, that is why seeing the modem's docsis report would have been interesting.