Network congestion(?) fresh install

[mithrandir]

Hello,

I have a fresh proxmox install, all default settings with my physical server connected directly to my ISP router+modem (I have removed all my own switches and routers to eliminate them as potential issues).

Anytime I initiate large network activity from proxmox (e.g. updates, CT template download) my ISP router becomes unresponsive to the rest of my devices/network. During these moments of large network activity from proxmox, I try to ping the ISO router from another system on the network, but get very large response time followed by a request timed out. The web GUI also becomes unresponsive, as do my other systems and any network tasks they are performing.

When I am able to cancel the download, or if the GUI is unresponsive and I just let the download finish on its own, my network activity seems to return to normal.

This issue doesnt seem to happen when I full saturate my download on my other networked systems directly connected to the ISP router. Thus it leads me to believe there is something going on from proxmox that is impacting my ISP router to perform its function normally.

I have a realtek 8118 NIC, which some have complained with having issues in Proxmox 8+, but they didnt appear to be the same issue I am having. Regardless I tried to perform the fix they mentioned (installing the older driver r8168 instead of r8169 via https://gist.github.com/SQLJames/fe6fcd5e819d864986ce2eff6ad350da, but ran into errors during that process). Didnt want to go down the rabbit hole of trying to fix that problem since it didnt appear to be the same symptoms i was suffering from.

I have also tried switching ports and cables to no avail.

Any help would be appreciated.

 

[sw-omit]

If you force the Ethernet-adaptor that you've got connected to your modem to 100 mbit/full duplex, does it then still weird-out?
You can temporarily do that with this command:
ethtool -s eth0 speed 100 duplex full autoneg off
(replace the eth0 with the correct adaptor name of course, to reset it, use speed 1000 and autoneg on or reboot the server)

If it does not: It might be the speed after all (and setting up a better speed-restriction might help you resolve it)
if it does: Then it's the type of traffic it sends/receives

 

[mithrandir]

Thank you for the response! Changing the port speed to 100 has remediated the issue. Any ideas on next steps?

Leaving it at 100 long term wouldnt be ideal, and I suppose if there are ways to further restrict the speed it and find a good balance that could be something I could do, but having access to the full link speed by figuring out the root cause would be great.

 

[sw-omit]

First I would look if your router(s) maybe have some kind of traffic-shaping option built in, so they can limit traffic to/from JUST the proxmox-host IP which exits your network (which would leave any other traffic-speeds intact).

Also as a more general question, if you run a (debian) VM, and it is downloading updates (with the physical ethernet set to 1000 and/or autoneg), does it then happen too? (For example grab the debian 12.0 iso so you have plenty of updates to download).

 

[mithrandir]

Just tried, and yes, still having the same network issues when I have a debian VM downloading updates.

 

[sw-omit]

How did you try to saturate the network off-proxmox before btw? And did you try it with multiple (not-proxmox) systems at the same time (and then ping from proxmox)?

 

[mithrandir]

Used 2 windows computers to downloaded a couple large files while running multiple speed tests simultaneously, just tried to maximize the amount of bandwidth I was using, and then pinged the router from proxmox. Results were fine, normal ping response times.

 

[Ericmann]

It sounds like your Proxmox server is overwhelming your ISP router. You might want to try limiting the bandwidth usage of your Proxmox server during large network activities. Additionally, updating your NIC drivers or using a different NIC could help resolve the issue.

Implementing bandwidth management and monitoring can optimize network performance and prevent such issues. This approach might be beneficial for maintaining a stable network environment.