Supports 1000mbps but receives at 100mbps

iamserver

New Member
Jan 8, 2025
4
0
1
I installed proxmox and replaced the router with pfsense in it. I used 100mbps until now, but I contacted ISP to upgrade to 500mbps. When I use the router of the telecommunications company, 500mbps is normal. However, when I change to pfsense, I get almost perfect 100mbps. (For example, 99mbps).

I went to datacenter > proxmox > shell instead of pfsense and measured the internet speed, and it was 100mbps and the speed was limited to 100mbps. (I measured it with ethtool)

The network device I use is I350 server LAN card. enp1s0f1 is lan and enp1s0f0 is wan. Just in case, I tried to communicate between the server's enp1s0f1 (lan) and the local computer with iperf3, and I got 1000mbps.

Oddly enough, enp1s0f1(lan) communicates at 1000mbps, but enp1s0f0(wan) communicates at 100mbps. Just in case, I tested it by switching wan and lan. I also checked by switching 5e and 6 of the LAN cable. I also switched the LAN cable, but it was the same. I don't know what to do. Below, I will show you as many network settings as possible and my structure diagram.

스크린샷 2025-03-15 230822.png스크린샷 2025-03-15 221352.png스크린샷 2025-03-15 221234.png스크린샷 2025-03-15 202009.png
 
Does the WAN port directly connect to your ISPs modem/port/whatever? You could try to manually force the speed to 1.000Mbps by using

ethtool -s enp1s0f1 autoneg on speed 1000 duplex full
 
Does the WAN port directly connect to your ISPs modem/port/whatever? You could try to manually force the speed to 1.000Mbps by using

ethtool -s enp1s0f1 autoneg on speed 1000 duplex full
Yes it is. WAN is directly connected to ISP. Also the command you gave me is to fix the speed of enp1s0f1(LAN) which is already working properly at 1000mbps. I tried changing enp1s0f1 to enp1s0f0(WAN/currently 100mbps where the problem is) and ran it but the network stopped. I restored it back to the original state with sudo ethtool -s enp1s0f0 autoneg on.
 
No news on this issue? I have the exact same problem with Proxmox 8.3.x with Proxmox 7 it works with no issues. I am pretty sure it is something with proxmox because I made a backup of the instances, reinstalled proxmox and restored the same instances with no changes at all.

Oscar.
 
No news on this issue? I have the exact same problem with Proxmox 8.3.x with Proxmox 7 it works with no issues. I am pretty sure it is something with proxmox because I made a backup of the instances, reinstalled proxmox and restored the same instances with no changes at all.

Oscar.
I solved this problem. Do you live in Korea? I live in Korea. The reason is that Korean telecommunications companies played a trick. Normally, 100Mbps or more are communicated with 8-wire UTP cables. However, Korean telecommunications companies created their own standards to operate at 500Mbps or 1G with only 2 or 4 wires. In the end, my international intel LAN port thought it was 100Mbps. To prevent this, you can switch the router provided by the telecommunications company to bridge mode or place iptime's igmp switching hub in front of the server. I don't know where you live, but ask your telecommunications company.
 
Any time I see a 1 Gbps NIC negotiate to 100 Mbps (which according to the output of ethtool, yours did), I always suspect a bad cable. 100Mbps only requires 2 pair of wires, where 1 Gbps requires 4 pair. A bad cable will happily negotiate 100 Mbps even if the hardware is capable of 1 Gbps.