I have directly connected my PC to the HFC modem.

No issues with IPv6 speeds bypassing the ER605 router.

13499192767.png (750×400) (speedtest.net)

13499195006.png (750×400) (speedtest.net)

Disabled IPv4 to test again.

Speedtest.net needs ipv4 to load.... so I used Fast.com and received 910mbit download result. Definitely something with the ER605 and IPv6 performance.

  @add1n1 

on fast.com you get full-speed over the ER605 or not? 

I could not follow which result was in which configuration.

And do you have more than one WAN and maybe Load-Balancing enabled? 

Do you have a static IPv6 prefix from your provider? Why not using pass-trough mode?

  @RobertMEF 

Hi mate, 

Only a single WAN in current setup.

On fast.com I do not get full speed if only ipv6 is enabled on my PC ethernet port, 300-250mbit.

If only ipv4 is enabled on my ethernet port, i get 900mbit+ speeds.

with both enabled fast.com prefers ipv6 - so i get same results as only ipv6 enabled 300-350mbit.

bypassing the ER605 with direct ethernet cable to HFC/cable modem I received full 900+mbit speeds on IPv6.

There is a bottleneck with IPv6 on ER605.

@Fae 

Why am I not using passthrough?

Passthrough mode means your clients get an IP address from the ISP's dhcpv6 server. This mode should only ever be used in the event that it is the only way to get online with your ISP.

Passthrough mode means your LAN clients will take a WAN IP address out of the WAN /64 address pool, that is allocated hopefully just to you, but more often the /64 is for all customers in your area.. Meaning your LAN clients may end up with IP addresses in the same subnet as your neighbours.... that's a big no no.

(in the event where your ISP has LAN prefixes available, meaning they are only expecting routers in your area to take one address out of the WAN /64 pool for your area)

My ISP only issues a singe IPv6 address /128 to the WAN, and a static /56 is available via prefix delegation for the LAN.

This closely reflects best practice, the WAN should be from a pool of /64 addresses, but the /128 allocated is perfectly fine (and not related to the issue)

  @add1n1 

add1n1 wrote

 

This closely reflects best practice, the WAN should be from a pool of /64 addresses, but the /128 allocated is perfectly fine (and not related to the issue)

just wondering, here in Europe we get dynamically assigned prefix delegations (which do change every 24h hours) so there is no way to setup it in a static manner and therefore I cannot use a simple modem. I still need the router of my ISP doing all that internal DHCPv6 stuff.

At least we need to understand your setup, as you can see, there a quite some differences around the globe. So its relevant to say the least.

How high is the CPU utilization? Can you see any difference between speedtesting IPv4 and v6? 

  @RobertMEF 

I certainly have an interesting CPU graph on the ER605.

OC200 was updated last night hence the break @ 2am.

IPv6 speedtest:

IPv4 speedtest:

  @add1n1 

thats indeed quite interesting, but there is no correlation to traffic or anything else. Here is an example of my er7206, Ive tested IPv6 first and then IPv4 with full gigabit and you can clearly see, where the CPU-load is coming from. So what is running on your er605 producing that kind of spikes?

  @add1n1 Please note Ipv6 does not currently have a firewall. You are reliant on your devices firewall.

See the following feature request.

https://community.tp-link.com/en/business/forum/topic/274222