RT-AC87R slowness with static routes

[iHavoc]

Hi All,

I assume the answer is going to be a limitation of the Asus RT-AC87R router, but thought would ask anyway.

I have a layer 3 Cisco switch with 7 VLANs defined on it for a VMware lab I use for work. I have defined all my static routes in the Asus router and everything works. I can communicate between the default untagged VLAN of the Asus and to all the tagged VLANs on the Cisco. Been working for over a year.

I recently purchased a new NAS and realized I was not getting write speeds advertised. The NAS was on a VLAN on the Cisco switch and my desktop was hardwired into the Asus router directly. With this I was only getting 47 MB/s max write speeds and should have been getting over 110 MB/s. If I connect directly to the Cisco switch on the same VLAN or any other VLAN defined on the Cisco switch, I get the ~110 MB/s throughput writing to the NAS. Also if I put the NAS on the Asus untagged VLAN I can get the same performance from my desktop plugged into the Asus router.
The issue seems only when traffic has to use the static route table in the Asus router that I get over a 50% reduction in performance.
Anyone have any ideas or thoughts? I don't have an issue buying a newer Asus router but afraid I will run into the same limitations.
Trying to avoid a separate WiFi AP and Router if possible.

Besides the static routes, I also have OpenVPN configured on the router and just about everything else off. No AI Protection, no QOS, no external devices like usb printers or hard drives connected.


Thanks,
Greg

 

[L&LD]

I can't see how this can be a limitation of the router?

Is the same throughput reduction observed for other devices on the wired Asus RT-AC87U LAN?

Are the RT-AC87U CPU's pegged when doing that same transfer test?

Is the slowdown on the Cisco switch by any chance? Are the Jumbo Frame support options identical on all (ideally, these should be at default 1500)?

If the throughput between wired 'AC87U devices is the limiting factor, when was the last time you did a full reset to factory defaults on the router? What firmware are you using (stock or RMerlin)?

If it has been many months/many firmware updates ago that a full reset, it may help to do so now.

I suggest RMerlin 384.16_0 release final (or the just as stable 384.17 Beta 1) if stock firmware continues with these issues after a full reset (with 'Initialize all settings checked too).

The following links may be helpful to get your router back to a good/known state if the other suggestions above don't fix the issues you face directly.

https://www.snbforums.com/threads/ax88-packet-loss.62891/#post-563326

M&M Config https://www.snbforums.com/threads/n...l-and-manual-configuration.27115/#post-205573

Nuclear Reset https://www.snbforums.com/threads/major-issues-w-rt-ac86u.56342/page-4#post-495710

The M&M Config is a subset of the Nuclear Reset, FYI.

HTH.

 

[iHavoc]

Thanks for the reply L&LD.

The same throughput reduction is seen on any device on the wired AsusRT-AC87U VLAN.

I will have to check the CPU when doing a transfer, but cannot get a real test right now as I am in the process of rsyncing new NAS to old NAS for backup, since it is the initial first sync will take a day or 2.
I might still give it a go in a bit just to see how the new NAS behaves with high load though

Slowdown is definitely not on the Cisco switch, it is a 3750G 48 port switch, as mentioned connecting to another VLAN on the Cisco switch and I can transfer at expected speeds. I am not running Jumbo Frames as the 3750G only supports jumbo frames at the switch level, not port by port, so using default 1500 mtu size.

I have not full reset the router in about 1 - 1.5 years or so when I last played with Merlin, so currently running stock with latest updates. A factory reset seems like a good option to try and RMerlin if that does not help. Current stock firmware is - 3.0.0.4.382_51939.

Will update after I reset the router.

Thanks

 

[iHavoc]

Was able to test a the Asus RT-AC87U core 1 cpu hits 96% and cpu 2 hits 38% when I transfer data to the NAS on the cisco VLAN from the Asus VLAN, when I do the data transfer with the NAS on the Asus RT-AC87U VLAN the cpu for core 1 is 7% and core 2 is 1%. So the slowness is definitely happening in the Asus router, ram usage is the same with either test. Next I am going to try the Nuclear reset option with the stock Asus firmware and then the RMerlin if that does not help. When I do it will be the base settings plus only the 1 static route to the NAS VLAN for testing.

 

[iHavoc]

Well I followed the nuclear reset option and flashed the latest Asus-wrtmerlin 384.13_16 for the Asus RT-AC87R and the issue still remains. Seems like this is a limitation of this router as I suspected. The CPU on Core 1 goes to max and Core 2 goes up to 32-50% . The data transfers between the router and the static routes just overloads the router. I realize this is an older router but wanted to wait for the WiFi 6E routers before I upgrade ( I know it was only ratified the other day )
I have a workaround by running my NAS with 1 NIC on VLAN 1 and the other on the other Cisco VLAN. Guess it will have to do for now and I will bond them in the future.
About the only good thing is since the nuclear reset the Asus router interface is snappier again

Thanks again L&LD but I don't think there is much else that can be done here.