RAX80 & CM1150v with aggregated link & gigabit Xfinity giving me consistent gig+ speeds using Xfinity app. Imac wired to RAX80 cannot complete a speedtest due to ethernet disconnecting ("fix": reset = network prefs / inactivate / activate -or- iMac restart). Happens irregularly in normal iMac use also. When occurs can use iPhone + Xfinity app to speedtest router-modem link and the aggregated link is good. I have tried the usual cable & port swapping; adding a switch; Big Sur reload; location change;... ad nauseum. A CalDigit Thunderbolt3 dock connected to iMac is immune with same wiring setup. Also note similar issue of dropped iMac wired ethernet with an aggregated Arris SB8200 mode & same RAX80 (1-cable not tried, see below) Chanced upon fact that disconnecting one of the aggregated cables "solves" the iMac ethernet problem while of course limiting my speeds to 900-950 Mb/sec. Apple has no answers... iMac issue? RAX80 issue? CM1150v issue? Aggregation bug? A2cents2017 iMac 5k Big Sur, RAX80 router, (aggreggated) CM1150v modem, (wired) EAX80 extender, CalDigit TS3+ dock

I wouldn't use wan port aggregation. I had issues with it and while its nice for that extra uptick in speed, it wasn't worth it for me on consumer devices. And it wasn't just netgear that had issues. I had a arris SB8200 that was consistently having issues with wan aggregation. i stopped attempting it and switched to a cax80 or a cm2000 depending on what i have setup for speeds >1gig.

I agree on SB8200 comment. I suffered speed declines after 1-2 weeks, then later after 1-2 days. Resetting either end of the aggregated link would address that issue but just not a reliable setup. Hence the CM1150v modem as I switched off my landline and ported its #, on the off chance that aggregation might work. ...And it does work (up to 15 days up before provisioning for phone at 1.1-1.2 Gb/sec), except for my new calamity. My CalDigit dock is happy as a clam, just not the iMac itself. A2cents

Port aggregation has been hit or miss since it came out. See the move from netgear to devices like the cm2000 or CAX80. the 2.5g port is much more reliable than fighting with port aggregation. You don't see quite the same issues with port aggregation on business class products but the consumer size has been really sketch in my experience.

is the mac the only device effected when LAG is enabled on the CM and RAX router? I presume you do have the mac connected to a open port not used by LAG right?

RAX80 arrangement: WAN port & port #1 are LAG to modem; iMac is port #3 cabled direct without switch; port #2 is an unmanaged switch; ports #4 & #5 are managed switches (because ports #4 & #5 "must be" managed switches if used). Other devices still function on LAN after iMac disconnects... for instance a wired Dell laptop accesses the web via router / network; various WIFI devices unaffected as well. Meanwhile Xfinity app (on iPhone, WIFI to RAX80) says speed 1.2 Gb/sec over LAG to modem / web. A2cents

RAX80 - CM1150v port aggregation cancels wired iMac ethernet (OK if single cable router-modem link)

15 Replies

plemans
Guru - Experienced User
Dec 17, 2020
I wouldn't use wan port aggregation. I had issues with it and while its nice for that extra uptick in speed, it wasn't worth it for me on consumer devices.
And it wasn't just netgear that had issues. I had a arris SB8200 that was consistently having issues with wan aggregation.
i stopped attempting it and switched to a cax80 or a cm2000 depending on what i have setup for speeds >1gig.
- A2cents
  Aspirant
  Dec 17, 2020
  I agree on SB8200 comment. I suffered speed declines after 1-2 weeks, then later after 1-2 days. Resetting either end of the aggregated link would address that issue but just not a reliable setup.
  
  Hence the CM1150v modem as I switched off my landline and ported its #, on the off chance that aggregation might work. ...And it does work (up to 15 days up before provisioning for phone at 1.1-1.2 Gb/sec), except for my new calamity. My CalDigit dock is happy as a clam, just not the iMac itself.
  
  A2cents
  - plemans
    Guru - Experienced User
    Dec 17, 2020
    Port aggregation has been hit or miss since it came out.
    See the move from netgear to devices like the cm2000 or CAX80. the 2.5g port is much more reliable than fighting with port aggregation.
    You don't see quite the same issues with port aggregation on business class products but the consumer size has been really sketch in my experience.
FURRYe38
Guru - Experienced User
Dec 17, 2020
is the mac the only device effected when LAG is enabled on the CM and RAX router?
I presume you do have the mac connected to a open port not used by LAG right?
- A2cents
  Aspirant
  Dec 18, 2020
  RAX80 arrangement: WAN port & port #1 are LAG to modem; iMac is port #3 cabled direct without switch; port #2 is an unmanaged switch; ports #4 & #5 are managed switches (because ports #4 & #5 "must be" managed switches if used).
  
  Other devices still function on LAN after iMac disconnects... for instance a wired Dell laptop accesses the web via router / network; various WIFI devices unaffected as well. Meanwhile Xfinity app (on iPhone, WIFI to RAX80) says speed 1.2 Gb/sec over LAG to modem / web.
  
  A2cents
  - FURRYe38
    Guru - Experienced User
    Dec 18, 2020
    What happens if you connect the Mac to one of the switches?

Forum Discussion

RAX80 - CM1150v port aggregation cancels wired iMac ethernet (OK if single cable router-modem link)