RouterOS v7.2rc1
Router's model RB5009UG+S+in

I have a 1000Mbps downlink connection to my ISP.
When connected via the 2.5G link on port 1 to the ISP cable modem, the connection speed maxes out at about 500Mbps
When removing the 2.5G negotiation speed on ethernet1 inside RouterOS and connecting to the cable modem, the speed is around 950Mbps

Steps to reproduce the issue;
Enable "2.5Gbps Full" advertise on Interface Ether1 -> Internet speed test goes to ~500Mbps
Remove "2.5Gbps Full" advertise on Interface Ether1 -> Internet speed test goes to ~900Mbps

Please see picture: Configuration export (use '/export hide-sensitive' command); This problem is affecting multiple users of RB5009, just a couple of examples:
viewtopic.php?t=179145
https://www.reddit.com/r/mikrotik/comme ... than_1gbe/
https://www.reddit.com/r/mikrotik/comme ... 25g_vs_1g/

Thank you.

Have you reported this on https://help.mikrotik.com/servicedesk ?
if not, I recommend you doing it, as via the forum they may not see it.

I can replicate this on 7.1.1 and the newly released 7.2rc3.

did you tested the same cable modem connected 2.5g computer or router?
the issue may be with the cable modem itself.
I had issues recently with an wireless access point that had a bug when connected to 2.5g port I had really slow speeds, that did not happen when connected at 1G.
Do you know if that particular cable modem have a Broadcomm SoC?

I have the same issue and there are a ton of others out there having it as well. In fact I haven't seen anyone claim that the 2.5G port works for them. It seems to be an issue when you go between speeds.

2.5G port - WAN
SFP+ port - S+RJ10 connected to PC at 2.5G

In this setup the 2.5G PC can get the full 1400mbps from the WAN connection. But any 1G device on the network suffers from the 500mbps download speeds. If the speed settings on the 2.5G port are changed to only advertise 1G then all devices are able to reach 900mbps.

I have the same problem with the 2.5g port but in an opposite configuration. I made my own post about it:

viewtopic.php?t=183165

In my configuration my WAN port is on a 1g port and my computer is on the 2.5g port on LAN bridge. Since my setup is opposite, my lower speed is on upload rather than download which indicates that the problem is 2.5g port sending. My behavior is exactly the same, if I remove the 2.5g advertisement and force the computer to connect at 1g my upload speed returns to normal. By the way my computer on the 2.5g port has an Intel I-225V NIC built into the motherboard.

I also had another problem with the 2.5g port that I'm not sure is related but may be. I noticed that at 2.5g if I upload large amounts of data to the internet (this occurred during my nightly remote backup), the 2.5g connection would go down. Windows would show a cable connected but no internet, renewing the IP address hangs forever, can't ping or connect to anything. All other devices on the RB5009 were fine and had internet, just my computer on the 2.5g port loses connection and never returns. Only thing I found that fixed it was to reboot the PC, never had to reboot RB5009 to fix it. It seems like this is a related problem because it only occurs when my computer uploads large amounts of data, downloading had no problem. Since removing the 2.5g advertisement and running at 1g, I no longer have this problem. For this reason the 2.5g port is unusable at 2.5g to me at the moment which is disappointing.

I have the same problem with the 2.5g port but in an opposite configuration. I made my own post about it:

viewtopic.php?t=183165

In my configuration my WAN port is on a 1g port and my computer is on the 2.5g port on LAN bridge. Since my setup is opposite, my lower speed is on upload rather than download which indicates that the problem is 2.5g port sending. My behavior is exactly the same, if I remove the 2.5g advertisement and force the computer to connect at 1g my upload speed returns to normal. By the way my computer on the 2.5g port has an Intel I-225V NIC built into the motherboard.
[...]

Hi,

I also have a MB with the Intel I225v, are you aware of it's hardware bugs? there is multiple offers to "fix it" but notthing actually effective. there is an fixed HW ver, but most of us got stuck with the bugged one. the only way to know if you have an affected one, is looking on the chip itself, under the motherboard heatsink.

I got mine working "okay" after a combination of a older driver and a nic firmware update. if you let windows update the driver you will get slow speeds, I actually had issues even when in 1g mode.
P.S: This test is a local intra-vlan to my DMZ that is in a server connected to the SFP+ port at 10G.

I'm getting about the same performance as jookraw using a similar setup though the 2.5G NIC I'm pointing it at is a RealTek rather than an Intel. It seems the RB5009 2.5G is ok talking to a RealTek. So far I've just been playing with it. I'm new to RouterOS and haven't deployed it yet. When I do I'll be pointing the 2.5G port at a Comcast-approved cable modem that I fortunately haven't bought yet. After seeing this Reddit post https://www.reddit.com/r/mikrotik/comme ... _than_1gbe/ I think I'll go with the Netgear CM2050V modem. It's one of my two options for 1.2G service. The other is a Motorola MT8733 WiFi cable router. I'd have more options if I didn't have phone service. I figured I'd wait to upgrade my modem until I got the RB5009 up and running, then after upgrading the modem upgrade my service.

The machine I have the 2.5G port on the RB5009 plugged into has a RealTek RTL8125 with firmware rtl8125b-2_0.0.2 07/13/20, running the stock driver included in RedHat 8.5. Test setup is basically:

RHEL8 "Server" RTL8125 2.5G - Cat6 - RB5009 2.5G - RB5009 SFP+ - 10G MMF - CRS326-24S+2Q+RM - 10G MMF - Solarflare sfn8522-plus "Workstation" Win10/RHEL8 dual boot

IPV4 IP V6 Normally the server machine uses a 10G Mellanox ConnectX4 and a DAC cable to the CRS, but I rearranged things to test the RB5009. The CRS is basically in dumb mode for now, though I'll be using VLANs once I get the RB5009 deployed.

There may be hope, Mikrotik seems to have reproduced the issue.

We reproduced a similar behavior locally. We are looking forward to improving such behavior with different link speeds in further RouterOS releases.

There may be hope, Mikrotik seems to have reproduced the issue.

We reproduced a similar behavior locally. We are looking forward to improving such behavior with different link speeds in further RouterOS releases.

Did they post this somewhere or is this in response to a support ticket?

Did they post this somewhere or is this in response to a support ticket?

Sorry, left that out. It was in response to a support ticket where we've been passing supout files, scenarios, etc. I'm eagerly awaiting the next testing branch update to scour over the change log that's for sure.

Thanks! I've been looking for updates on this issue every other day and this is promising news.

Did they post this somewhere or is this in response to a support ticket?

Sorry, left that out. It was in response to a support ticket where we've been passing supout files, scenarios, etc. I'm eagerly awaiting the next testing branch update to scour over the change log that's for sure.

I had similar problems with a Realtek RTL8125B. Turning flow control on fixed the problem.

I had similar problems with a Realtek RTL8125B. Turning flow control on fixed the problem.

For me, flow control was a completely separate issue but solved just general issues on my network with mismatch link speeds causing buffers to overflow.

I'm trying some test builds from MikroTik, will report back!

Three of the four test versions worked very well! Encouraging, I'm sure more to come soon from Mikrotik! I've restored to 7.2rc4 for now, not going to run those alpha builds

They had me test the alpha firmware as well and it definitely clears up the issue. Woohoo!

They had me test the alpha firmware as well and it definitely clears up the issue. Woohoo!

Did all work the same for you? One of them, the last one v4 seemed to still have issues on my side.

They had me test the alpha firmware as well and it definitely clears up the issue. Woohoo!

Did all work the same for you? One of them, the last one v4 seemed to still have issues on my side.

Same here, the first three were good and the last one had issues.

SergeP:
I've tested all four 7.99's. I use ether5,6,7,8 as LACP. I tried 1G and 2.5G on ether1. Looks like all builds do not increase speed above 1G in any settings. (Use different computers at the same time, It's combined speed). 1G +2G(LACP) gives 450Mbits + 450Mbits - total < 1G
V1: 2.5G - 937Mbits
1G - 938Mbits
V2: 2.5G - 935Mbits
1G - 938Mbits
V3: 2.5G - 860Mbits
1G - 935Mbits
V4: 2.5G - 425Mbits
1G - 933Mbits

7.2rc4 2.5G - 230Mbits
1G - 945Mbits

Direct cat6a 30" 2.5G NIC to cable modem 2.5G port gives 2040Mbits

heads up, from viewtopic.php?t=179145

Also, V1 worked best for me.

Same issue here. How can I request for the alpha firmware?

I can confirm I found noticed this just this morning on 7.2.1. I have gigabit cable service and my DOCSIS modem has a 2.5G ethernet port. Tests with 2.5G ethernet enabled get me ~600Mb/s. If I remove 2.5G from the ANEG profile I get 940 all day.

I turned TX Flow control on ether1 but it's not actually sending any TX Pause frames. I'm using a 10G SFP downstream, so looking at the block diagram I don't see anywhere that might actually call for flow control. Besides traffic from the 10G CPU interface towards the 2.5G ether1.

However looking at /interface/ethernet/switch/print stats does show many RX Pause Frames. Meaning something is overflowing and attempting to send pause packets internally to the router.

The 7.3 series works well for me with the cpu-flow-control on the switch. I'm running 7.3beta37 right now, and all is well for 10G, 2.5G and 1G hosts.

Something to note is that I had a lot of problems with my CRS328 switch in RouterOS, Mikrotik has confirmed tx-flow-control does not work correctly in RouterOS. I switched to SwOS and also tried other 10G/1G switches with flow control and I have zero issues now. I can saturate any mix of link speeds without issues on my network now.

I can confirm running v7.2.3 on RV5009.

At 2.5Gb I get 500Mbs - 600Mbs

When I turn it down to Gigabit I get full Gigabit around 930Mbs

Any chance of a fix making it into the v7.2 branch while we wait for v7.3 to hit stable?