Low LAN to WAN throughput on Asus RT-AC5300

[ai4at]

I purchased the router some 50 days ago, and until recently it worked great. I have a 1GBps AT&T fiber connection and was getting 900+MBps on my wired devices.
Sometime in the past week or so, the LAN to WAN throughput has dropped to 50MBps down and 100MBps up. I made no changes, just added some more devices on the network. Connecting directly to AT&T's router gives me the full 1GBps, so the problem seems to be with the Asus.
I am running AsusWRT-Merlin 384.7_2. No QoS or filters enabled, just a bunch of static IPs and 4 measly port forwarding rules, all of which were there before this slowdown started to happen.
I tried making most of the DHCP leases static, since I read somewhere that it might impact performance, but that didn't seem to have any effect.
Any idea what could be causing this?

 

[VirtualLarry]

Sure that you're not mixing MB with Mb? 50-100MegaBYTES is normal, for a GigE connection. Likewise, 900Mbits/sec.

 

[ai4at]

While this gave you the opportunity to be snarky, the fact that I said I had a 1GBps connection should have answered your question: yes, I should have said Mbps and Gbps, not MBps and GBps, as nobody who would have a 1GBps connection (if such a thing existed) would use an Asus router to manage it.

The situation was resolved on SNBforums : AT&T may have made some updates in their router that required a MAC address clone.

 

[VirtualLarry]

Sorry, didn't mean to be snarky, but we get one or two new people a week in here, it seems, that don't know the difference, and they complain that they get "200Mbit/sec speedtest scores", but then their browser reports, 20MB/sec downloads. They don't realize that they are measuring different things.

And you did label your internet connection as "1GBps" connection, which made me assume that you were one of those people.

I'm somewhat surprised to hear that it's a MAC-clone issue, as generally, those are either connected, or not-connected issues. (Eg. ISP refuses connection if registered MAC address not seen. Not throttling.)

 

[ai4at]

No offense taken, thank you for the reply.
I was just as surprised as you. Turns out it's really an issue with the AT&T router's DMZPlus mode, which all of a sudden has decided to misbehave. If I set the Asus as a regular client, I get the full bandwidth. Cloning the MAC was just another way of accomplishing that.