Slow LAN throughput on RAX120 since upgrading modem to CM2000
After upgrading my connecting modem to a NETGEAR CM2000, my RAX120 has seen a dramatic loss in throughput only to LAN interfaces. Speeds went from full 1Gig down to 500Mbps when only using a LAN interface after upgrading the modem. WiFi Speeds have stayed the same at around 800Mbps down via WiFi 6 and speed tests from the WAN port on the RAX120 are showing the correct speeds of over a gig.
Tried new cabling to be safe and tested throughputs between all my LAN that are connected via the LAN interfaces and was only getting around 250Mbps to 300Mbps between each of them. Not running any QoS, Traffic monitoring, etc.. that might be causing bandwidth or processing restraints on the RAX120.
What I’m thinking is that since the WAN port was originally negotiating at 1gig on my old modem and then activating the multi gig interface (2.5Gig) when I upgraded, the memory allocation to each of the LAN interfaces might have gotten reduced to support the multi gig interface. This is the only thing I can think of but have no proof or knowledge of verifying that to be true. Would anyone else might know what is going on here or might have had the same or similar issue?
After upgrading my connecting modem to a NETGEAR CM2000, my RAX120 has seen a dramatic loss in throughput only to LAN interfaces. Speeds went from full 1Gig down to 500Mbps when only using a LAN interface after upgrading the modem. WiFi Speeds have stayed the same at around 800Mbps down via WiFi 6 and speed tests from the WAN port on the RAX120 are showing the correct speeds of over a gig.
Tried new cabling to be safe and tested throughputs between all my LAN that are connected via the LAN interfaces and was only getting around 250Mbps to 300Mbps between each of them. Not running any QoS, Traffic monitoring, etc.. that might be causing bandwidth or processing restraints on the RAX120.
What I’m thinking is that since the WAN port was originally negotiating at 1gig on my old modem and then activating the multi gig interface (2.5Gig) when I upgraded, the memory allocation to each of the LAN interfaces might have gotten reduced to support the multi gig interface. This is the only thing I can think of but have no proof or knowledge of verifying that to be true. Would anyone else might know what is going on here or might have had the same or similar issue?
Log in to your RAX120 and go to the Advanced -> Setup -> Internet Setup menu. Select as your WAN port preference your multi-gig port. When you do this, your 1 gig WAN port on the back of your router has to remain with no Ethernet connections.
The Ethernet cable between the multi-gig modem output and your RAX120 multi-gig input is recommended to be Cat 6a. Short term, a good quality Cat 5e or Cat 6 will work for testing.
When you make changes to the configuration or the cabling connections you need to completely power down your LAN and perform a sequential startup. This allows the changes to take effect and the hardware to catch up.
Power down your modem and disconnect the Ethernet output cable. Power down your RAX120 (pull the power cord) and disconnect all Ethernet connections.
Power up your modem and give it ample time to boot and stabilize. One of the last indicators to illuminate will be the one for internet connection. Connect an Ethernet cable between the output of the modem and the multi-gig WAN port on your RAX120. No connection to the 1 gig WAN input port. Power up your router and give it plenty of time to boot and stabilize. One of the last indicators to illuminate will be the one for internet connection.
Use and Ethernet cable and connect a real computer to one of the four 1 gig output ports on the router and use a web browser to log in to your user interface. Go to the Advanced tab and Advanced Home screen. Click on the Show Statistics button and it will list your connections. The WAN connection should be multi-gig and when connected, the four LAN ports should be 1000M/Full.
Connect the rest of your network and test away. Recommend you use the Ookla native operating system application for testing (available in the play store).
Attached is a screen snip of the connection between my CM2050V and R9000. I use an SFP+/RJ45 adapter on the R9000 and a Cat 6a cable to the modem. Note no connection to the LAN 0 port.
Re: Slow LAN throughput on RAX120 since upgrading modem to CM2000
Thank you for the recommendation but after trying this, I’m still seeing the same 400Mbps to 500Mbps download speed on my LAN interfaces. Getting around 700Mbps to 800Mbps to the exact same server via Ookla on WiFi 6. Double checked and made sure that the connected LAN devices are negotiated at 1Gig and the WAN port itself is at a negotiated speed of 2.5Gig as well. All cable runs are Cat 6a and above with connection between the RAX120 and the CM2000 being a Cat 8 cable.
Thank you for the recommendation but after trying this, I’m still seeing the same 400Mbps to 500Mbps download speed on my LAN interfaces. Getting around 700Mbps to 800Mbps to the exact same server via Ookla on WiFi 6. Double checked and made sure that the connected LAN devices are negotiated at 1Gig and the WAN port itself is at a negotiated speed of 2.5Gig as well. All cable runs are Cat 6a and above with connection between the RAX120 and the CM2000 being a Cat 8 cable.
When you went through the process, did you make any changes in your existing configuration?
What specific Ethernet connected devices are your testing on? How are you testing?
Have you connected a computer direct to your modem to verify what throughput your ISP is delivering?
Re: Slow LAN throughput on RAX120 since upgrading modem to CM2000
Nope. No configuration was changed. The 2.5Gig port was already the preferred WAN interface. Testing with my PC and a separate laptop that are both connected via Cat 6a and are negotiating at 1gig with the RAX120. Verified with iPerf that both the PC and laptop are only able to get a max throughput in the 300Mbps range between each other and with WLAN devices as well.
I did bypass the RAX120 to tested directly from the CM2000 interface earlier today and was getting the expected 1gig speeds. Also ran a Speed test from the RAX120 WAN interface as well and was getting the expected download speed of over 1.2Gigs.
Have a feeling that this might be an hardware issue with something on the LAN interfaces NPUs. This is my only NetGear equipment so not too familiar with their designed as I mainly work with Cisco equipment day to day.
Nope. No configuration was changed. The 2.5Gig port was already the preferred WAN interface. Testing with my PC and a separate laptop that are both connected via Cat 6a and are negotiating at 1gig with the RAX120. Verified with iPerf that both the PC and laptop are only able to get a max throughput in the 300Mbps range between each other and with WLAN devices as well.
I did bypass the RAX120 to tested directly from the CM2000 interface earlier today and was getting the expected 1gig speeds. Also ran a Speed test from the RAX120 WAN interface as well and was getting the expected download speed of over 1.2Gigs.
Have a feeling that this might be an hardware issue with something on the LAN interfaces NPUs. This is my only NetGear equipment so not too familiar with their designed as I mainly work with Cisco equipment day to day.
If you are getting 1.2 Gbps downstream from the router, the router and modem are doing their jobs. I presume you are working with Windows devices? If not, please say so.
For Windows, make sure your network profiles on each machine are classified as private and not public. When you installed a new modem, Windows possibly sensed a new network and automatically classified it as public. See attached screen snip from a Windows 10 machine.
For data transfer rates between machines, do an internet search for SMBv1, SMBv2, and SMBv3 and Windows. Lots of reading material.
Re: Slow LAN throughput on RAX120 since upgrading modem to CM2000
Yes, there both running Windows 10. Just doubled checked to make sure that there still set to Private which there are. Thank you for the guidance on looking into the SMB stuff. Going to do some research on that tomorrow as I didn’t think of looking into that for this issue yet. Also going to try out testing two Linux machines as well on the LAN interface just to be extra safe tomorrow or later this week. Thank you for your help on this today!
Yes, there both running Windows 10. Just doubled checked to make sure that there still set to Private which there are. Thank you for the guidance on looking into the SMB stuff. Going to do some research on that tomorrow as I didn’t think of looking into that for this issue yet. Also going to try out testing two Linux machines as well on the LAN interface just to be extra safe tomorrow or later this week. Thank you for your help on this today!
You are more than welcome. Please post back what you find out. The public/private issue has nicked a lot of people lately, in particular when they connect a new machine with Windows 11 to an existing LAN.
When you make changes to the configuration or the cabling connections you need to completely power down your LAN and perform a sequential startup. This allows the changes to take effect and the hardware to catch up.
It can also help to reset the router so that it forgets any settings it had with the older modem.
Follow that startup sequence and it will configure itself to work with the new modem.
