RT-AX88U IPv6 Default GW Missing

[salami]

Hi all

I have used different models running Asuswrt-Merlin (legacy) for several years with the same ISP (Init7) and IPv6 has always worked very well.

Since upgrading to an RT-AX88U (the first time running a NG FW), the router no longer detects the default GW:

This obviously breaks all IPv6 connectivity. Manually setting the GW using the following command seems to "fix" the issue:

ip -6 route add default via fe80::523d:e5ff:fea8:b87f dev eth0

Thanks to the wonders of Asuswrt-Merlin, adding this to the wan-start script looks like a permanent fix. At least until my ISP changes its router...

The official FW from Asus shows the exact same issue.

Can anyone here help me analyze the root cause? Or how would you recommend reporting this to Asus?

Thanks!

 

[EmeraldDeer]

Hi all

I have used different models running Asuswrt-Merlin (legacy) for several years with the same ISP (Init7) and IPv6 has always worked very well.

Since upgrading to an RT-AX88U (the first time running a NG FW), the router no longer detects the default GW:

View attachment 17762

This obviously breaks all IPv6 connectivity. Manually setting the GW using the following command seems to "fix" the issue:

ip -6 route add default via fe80::523d:e5ff:fea8:b87f dev eth0

Thanks to the wonders of Asuswrt-Merlin, adding this to the wan-start script looks like a permanent fix. At least until my ISP changes its router...

The official FW from Asus shows the exact same issue.

Can anyone here help me analyze the root cause? Or how would you recommend reporting this to Asus?

Thanks!

I don't know the root cause or about reporting to Asus.
When I raised this issue in the forums, @themiron recommended an alternative work around where you enable IPv6 router advertisement. This works and avoids the specifics of adding a route.

# cat /jffs/scripts/wan-start
#!/bin/sh
CONFIG=$1
source /usr/sbin/helper.sh
#
#echo "1" > /proc/sys/net/ipv6/conf/all/accept_ra
#echo "1" > /proc/sys/net/ipv6/conf/all/forwarding
echo "1" > /proc/sys/net/ipv6/conf/eth0/accept_ra
echo "0" > /proc/sys/net/ipv6/conf/eth0/forwarding
#

 

[salami]

When I raised this issue in the forums, @themiron recommended an alternative work around where you enable IPv6 router advertisement. This works and avoids the specifics of adding a route.

Thanks a lot for sharing that! My first tests are positive, looks like this fixes my case as well. And it seems to be a lot more reliable than having the GW address in the script.

 

[Swistheater]

Thanks a lot for sharing that! My first tests are positive, looks like this fixes my case as well. And it seems to be a lot more reliable than having the GW address in the script.

it is better because that GW address could be dynamically changing and no telling how often your isp changes it... granted it probably rarely happens because ISP's can be cheap.

 

[universe83]

Bad coding from Asus
https://www.snbforums.com/threads/b...ta-is-now-available.56325/page-40#post-488165

 

[Swistheater]

Hi all

I have used different models running Asuswrt-Merlin (legacy) for several years with the same ISP (Init7) and IPv6 has always worked very well.

Since upgrading to an RT-AX88U (the first time running a NG FW), the router no longer detects the default GW:

View attachment 17762

This obviously breaks all IPv6 connectivity. Manually setting the GW using the following command seems to "fix" the issue:

ip -6 route add default via fe80::523d:e5ff:fea8:b87f dev eth0

Thanks to the wonders of Asuswrt-Merlin, adding this to the wan-start script looks like a permanent fix. At least until my ISP changes its router...

The official FW from Asus shows the exact same issue.

Can anyone here help me analyze the root cause? Or how would you recommend reporting this to Asus?

Thanks!

I believe asus might have released a firmware fix already I am not sure...., I think it is still in beta and you would have to wait for release of it and GPL of it to be compiled against merlins firmware... be patient.

Bad coding from Asus
https://www.snbforums.com/threads/b...ta-is-now-available.56325/page-40#post-488165

You have to forgive asus devs and the junior techs involved all this could be avoided if they fix things while it is in beta... Nevermind that and how occasionally spanish slips its way onto the english gui.