Network crashes after 20 minutes

[gtrovato]

Hi All,

I've a Proxmox 6.1.2 system with pfSense and Openmediavault guests (all with VirtIO driver),

I discovered an annoying issue on network that after about 20 minutes of constant load (downloading or uploading) crashes for some seconds.
The connection goes down and then goes up and nothing is reported on syslog of host and guests.

Do you've ever experienced this?
I've seen something reported over some forum, but dated some years ago.

Below my system.

Thank you!
Giacomo.

proxmox-ve: 6.1-2 (running kernel: 5.3.10-1-pve) pve-manager: 6.1-3 (running version: 6.1-3/37248ce6) pve-kernel-5.3: 6.0-12 pve-kernel-helper: 6.0-12 pve-kernel-5.3.10-1-pve: 5.3.10-1 ceph-fuse: 12.2.11+dfsg1-2.1+b1 corosync: 3.0.2-pve4 criu: 3.11-3 glusterfs-client: 5.5-3 ifupdown: 0.8.35+pve1 ksm-control-daemon: 1.3-1 libjs-extjs: 6.0.1-10 libknet1: 1.13-pve1 libpve-access-control: 6.0-5 libpve-apiclient-perl: 3.0-2 libpve-common-perl: 6.0-9 libpve-guest-common-perl: 3.0-3 libpve-http-server-perl: 3.0-3 libpve-storage-perl: 6.1-2 libqb0: 1.0.5-1 libspice-server1: 0.14.2-4~pve6+1 lvm2: 2.03.02-pve3 lxc-pve: 3.2.1-1 lxcfs: 3.0.3-pve60 novnc-pve: 1.1.0-1 proxmox-mini-journalreader: 1.1-1 proxmox-widget-toolkit: 2.1-1 pve-cluster: 6.1-2 pve-container: 3.0-14 pve-docs: 6.1-3 pve-edk2-firmware: 2.20191002-1 pve-firewall: 4.0-9 pve-firmware: 3.0-4 pve-ha-manager: 3.0-8 pve-i18n: 2.0-3 pve-qemu-kvm: 4.1.1-2 pve-xtermjs: 3.13.2-1 qemu-server: 6.1-2 smartmontools: 7.0-pve2 spiceterm: 3.1-1 vncterm: 1.6-1 zfsutils-linux: 0.8.2-pve2

 

[Stefan_R]

Are you sure this is related to virtualization at all? It sounds more like buffer bloat issues, as a shot in the dark, maybe assign more RAM to your router...

Also, does this happen between all VMs (or even the host), or just certain connections that get dropped (e.g. only connections through your pfSense, only connections between VMs, etc...)?

 

[wolfgang]

Do you've ever experienced this?

Yes.
The problem is FreeBSD arp cache implementation.
It does not update the ARPCache as Linux does.
So after 20min (default setting), the entry will be deleted.
And a new ARP discover-package will send out.
The solution to this behavior is to set the max_age to a higher value.

For more information see man arp(4)