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Solved GT-AX11000 what’s the max size of jumbo frames?

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DJones

Very Senior Member
GT-AX11000 what’s the max size of jumbo frames? My 10gbe adapter is capable of over 16000 bytes mtu obviously the router is only able to support 2.5gbe but what is the size of jumbo frames for the router? It’s just has a on / off toggle. Also are we able to adjust the jumbo frames mtu?
 
I suggest you enable it and find out. FWIW on my old RT-AC68U I could send 9KB packets between LAN devices. That was the maximum size my Ethernet adapter supported. It didn't change the MTU, that had to be done manually (or in a script). But the switch hardware in the newer routers is completely different now so YMMV.
 
I'm probably mis-remembering, but isn't jumbo frames part of the IPv6 specification or design, where the server-client negotiate MTU between/for themselves and auto-scale when that switch is set to on?
But yes, it is hardware-limited..."how big do these new routers go?" is a very interesting question to me.
 
As far as I know 1500 is default on ASUS for MTU, however jumbo frames use a mtu over 1500 bytes. As far as I was aware this wasn’t something that’s auto negotiated.. but maybe it is? I always thought you had to set both clients with the same mtu to avoid fragmentation.

WAN can set mtu, but that’s not what I need as I need to set the LAN’s mtu.
 
Merlin has stated on other posts that MTU is wan and jumbo frames are LAN, but on adapters such as Windows or Ubuntu setting jumbo frames is to change the MTU which is why I’m confused.

Does the router simply pass the packets on between two clients like a unmanaged switch without fragmenting it down to 1500 mtu from say 9000 mtu if you have jumbo frames enabled?
 
I'm probably mis-remembering, but isn't jumbo frames part of the IPv6 specification or design
No, you're thinking of jumbogram which is an optional IPv6 feature. Jumbo frames are just the payload part of an Ethernet frame. MTU is something different again.
 
Does the router simply pass the packets on between two clients like a unmanaged switch without fragmenting it down to 1500 mtu from say 9000 mtu if you have jumbo frames enabled?
Yes. FYI I've just enabled jumbo frames on my router and was able to send packets of up to 9702 bytes.
 
Yes. FYI I've just enabled jumbo frames on my router and was able to send packets of up to 9702 bytes.
Okay that’s interesting.

But does the same apply if your using a Wifi Mesh network. If as a mesh network, routed, or media bridge connecting Point to Point over wifi; I assume jumbo frames from the router doesn’t make the jump to the node except maybe locally among your LAN ports on each end. In my head you’d still have to drop it to 1500 mtu fragmenting it.

Just trying to determine a bottleneck. Locally on my routers LAN I can transfer at full speeds 100-200MBps on x2 1gbe round robin link aggregation NAS to Router to PC.

Alternatively SMB direct from NAS to pc via 2.5gbe is 200+MBps or via 5gbe is 300+MBps with jumbo frame 9014 bytes. (5gbe is bottlenecked by 3.0 usb speeds on usb eth adapter)

But my other computer wired via Ethernet on the node is significantly slower about 35-40MBps, the speeds don’t seem to improve when I bring the node closer to the router and it’s about the same speeds if the computer is plugged in via Ethernet or over AX wifi to the node.

The ax node to router link speed is 1441Mbps tx and rx about 180MBps. Is 40MBps around what I should expect?

Frankly would love to run some 10gbe sfp+ and say the hell with this router and mesh but the layout of the house doesn’t make that simple.
 
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Jumbo frames are Ethernet only, they're not applicable to WiFi.

I can't comment on the expected performance of AiMesh as I don't use it.
 
I believe Asus uses 9k. Set your adapter or hosts as larger as you like after enabling as the end points will negotiate the MTU. Anything that goes over the Internet will be 1500.

Morris
 
If your entire wired network doesn't support Jumbo Frames, don't enable it for any. If you want a reliable network.
 
Yes, thankfully it does all support jumbo frames at least anything that is wired. Wifi as you said it does not support jumbo frames so the IoT’s devices like tv’s are unaffected. Jumbo frames does provide a major throughput improvement from my NAS. Samba is unfortunately just a lazy mailman as one would put it. On Ubuntu they are still running Samba 4.13 which will be long term EoL in march, SMB Direct was only just introduced in that version. I’ve tried compiling newer versions a couple times but always run into some make errors and just give up.

Ultimately I guess I’m just up against the whims of wifi which is unfortunately just that kind of bag of worms. When I purchased the GT-AX11000 & RT-AX58U I was ultimately hoping for more throughput for what I felt was a higher end consumer router. Figured maybe it was just a matter of optimizing settings, but I don’t think that’s the case. Since ASUS and Broadcom are both locked down drivers I really can’t easily go poking around in the settings like I’d like. Used to enjoy some of the freedoms I’d get from using (buggy) dd-wrt on atheros routers.

Maybe ASUS will drop some better updates or something.. but not going to hold my breath.
 
If your entire wired network doesn't support Jumbo Frames, don't enable it for any. If you want a reliable network.

:-} Frequently, there is a fussy host...
 

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