Why is my LAN Speed so slow?

I just upgraded my Internet service from 100Mbps to 1Gbps but I am not seeing any improvement in LAN speeds. What am I doing wrong?

My new fast Internet arrives via Ethernet. When I plug the WAN cable directly into my notebook I see Speedtest results or around 940Mbps both up and down. But When I plug the WAN cable into my Vigor 2920 the LAN speeds are less than 100Mbps. Both the WAN connector and LAN connector are indicating that the router recognizes physical 1000Mbps connections. I am using the WAN2(Giga) port for this high speed service and I have a slower service connected to the WAN1 port only for failover. The MTU is set to 1340 but I don't recall when or why I chose that.I just tried changing it back to the 2920 default of 1442 but there was no change in the LAN speed.

I have very humble feature and configuration needs, just dual WAN for failover redundancy and the built-in VPN server for remote access. I don't use any of the router's security features and complicated LAN configuration functions and options which are all wasted on me.

Any ideas? Any tests I might try to figure this out?

tgold wrote:
But When I plug the WAN cable into my Vigor 2920 the LAN speeds are less than 100Mbps. Both the WAN connector and LAN connector are indicating that the router recognizes physical 1000Mbps connections. I am using the WAN2(Giga) port for this high speed service and I have a slower service connected to the WAN1 port only for failover.

The maximum WAN throughput for the Vigor 2920 seems to have been around 150Mbps (described as 'very high', back in 2010 :wink: ). You are going to have to upgrade the Router to a (much) later model to get anywhere close to your 1Gbps Internet service.

The fact you are getting less than 100Mbps, might indicate that the LAN device is not negotiating a 1Gbps link - though you seem to indicate this is not the case...

Many thanks @hornbyp.

Because the 1000Mbps LED indicator lights on the port sockets are illuminated I am trusting that Ethernet speed negotiation is not the failing cause.

At another site I replaced the 2920 by a 2952 and that has worked well. But that selection was made over five years ago and maybe something better is now available. If my needs are simply dual WAN and VPN, do you have any suggestions for what models (or even brands) I might consider?

The DrayTek Vigor 2927 appears to be a good match for my needs. Does anyone have any pro or adverse reports or experiences or any suggestions for alternatives?

tgold wrote:
do you have any suggestions for what models (or even brands) I might consider?

I'm just a domestic user these days - and my last Router purchase was a (second-hand) 2860n back in 2015 Since I moved out to the sticks, WAN speed has become largely irrelevant for me

Draytek's comparison chart is here: https://draytek.co.uk/products/comparison/router-comparison - the latest models all seem to (finally) have decent WAN firewall performance. There's lots of variations in features between the various models though.

I've used a 2927ac for a couple of years and am currently using a 2927ax

WAN throughput is not my major concern at present as I only have a 39Mb download connection.

There are a couple of threads on here about problems with the most recent firmware on the 2927 series, and I had problems with the 2927ac if I enabled IPV6. The 2927ax seems to be OK in that respect, although it does reboot itself every couple of days for no apparent reason on the current firmware. A new firmware is said to be in the offing.

Annoyingly, the 2927ax does not have the facility to use a wifi WAN connection (e.g. to a tethered phone) that the previous incarnation did, if that's of interest to you.

Those problems aside, it's fine 8)