how to troubleshoot dropped packets

godsavethequ33n

New Member
Mar 8, 2022
21
6
3
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I recently reinstalled netdata and have been receiving notifications like this:



1654648432841.png

Output of ip -s link show vmbr0


Code:
20: vmbr0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP mode DEFAULT group default qlen 1000
    link/ether fc:34:97:a1:31:7d brd ff:ff:ff:ff:ff:ff
    RX: bytes  packets  errors  dropped missed  mcast
    3881705530 12322876 0       491986  0       101866
    TX: bytes  packets  errors  dropped carrier collsns
    171668466551 13828385 0       0       0       0



Addition info if it helps at all:

/etc/network/interfaces

Code:
auto lo
iface lo inet loopback

iface eno1 inet manual

auto vmbr0
iface vmbr0 inet static
        address 192.168.1.125/24
        gateway 192.168.1.1
        bridge-ports eno1
        bridge-stp off
        bridge-fd 0

load average: 1.21, 1.29, 1.36

1 NIC. No HP switches. I have a TP-Link TL-SG108PE V3 and a NETGEAR GS308 on my network.

I have a constant ping to the Proxmox host IP, a VM IP on PM and out to google all from a pc on the network. I notice the Proxmox host IP and VM IP time out for 3 pings at the same exact time... ping to google is fine. At this same time my Plex direct streams on one of the VMs will stop to buffer as well.

What steps to I take to begin troubleshooting this?
 
Last edited:

shrdlicka

Active Member
Staff member
May 2, 2022
334
38
28
Hi,

looks like a hard problem to me :). It could be that your Proxmox server is so busy that it is dropping packets which would also stop the VMs on it from getting them. It could also be that there is some defective hardware.

I would first try to figure out if there is maybe some issue with high system load at the times when the packets get dropped.
 

godsavethequ33n

New Member
Mar 8, 2022
21
6
3
34
Code:
[ 1979.225665] e1000e 0000:00:1f.6 eno1: Detected Hardware Unit Hang:
                 TDH                  <1c>
                 TDT                  <be>
                 next_to_use          <be>
                 next_to_clean        <1b>
               buffer_info[next_to_clean]:
                 time_stamp           <100065d31>
                 next_to_watch        <1c>
                 jiffies              <100066760>
                 next_to_watch.status <0>
               MAC Status             <40080083>
               PHY Status             <796d>
               PHY 1000BASE-T Status  <3800>
               PHY Extended Status    <3000>
               PCI Status             <10>
[ 1979.353382] e1000e 0000:00:1f.6 eno1: Reset adapter unexpectedly
[ 1979.443144] vmbr0: port 1(eno1) entered disabled state
[ 1983.132165] e1000e 0000:00:1f.6 eno1: NIC Link is Up 1000 Mbps Full Duplex, Flow Control: None
[ 1983.132225] vmbr0: port 1(eno1) entered blocking state
[ 1983.132228] vmbr0: port 1(eno1) entered forwarding state

Just noticed this in the logs. Likely related. Coincides with the outages. Not sure what would cause this.

Using onboard NIC.

Code:
Base Board Information
        Manufacturer: ASUSTeK COMPUTER INC.
        Product Name: PRIME Z590-V
        Version: Rev 1.xx

00:1f.6 Ethernet controller: Intel Corporation Ethernet Connection (14) I219-V (rev 11)

Code:
Linux 5.15.35-1-pve #1 SMP PVE 5.15.35-3
 
Last edited:

godsavethequ33n

New Member
Mar 8, 2022
21
6
3
34
Disabling only tso as several others have recommend seemed to do the trick! Thank you!

Code:
ethtool -K eno1 tso off

Added to /etc/network/interfaces as well. Have not tested to see if it survives a reboot yet.
 
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