universe83
Occasional Visitor
Buy the RT-AC86u 5 days ago and when turning on the router, IPv6 works correctly for a few minutes, then it does not work.?
When IPv6 works the routing table shows the default route (WAN IPv6 Gateway), when IPv6 stops working the line with the default route (WAN IPv6 Gateway) disappears.
All this happens in official firmware. versions: 3.0.0.4.384.45149, 3.0.0.4.384.32799, I do not know if in previous versions it happens.
Also try the latest version of Asus merlin and the same thing happens.
(Excuse my language, my native language is Spanish)
Update 1:
My internet connection is VDSL2 50mbps down / 10mbps up.
My configuration is as follows: ISP -> Modem Huawei HG659 (In bridge mode) -> Asus RT-AC86U.
My ISP is DualStack (IPv4/IPv6), IPv6 Connection Type: Native with DHCP-PD
Update 2019-01-04:
After 1 month of testing, now I know when the problem occurs, when turning on the router for 31 minutes the devices in my network can access IPv6 sites (https://ipv6.google.com), the router can never reach IPv6 sites (probe from router GUI -> Network tools -> Network analisys -> Ping to ipv6.google.com)
After 31 minutes default route (WAN IPv6 Gateway) disappears.
Contact asus support and after several emails and tests they said:
"We found that the default gateway was removed caused by timeout occurred, we need to check if the router get the extended time packet"
And they sent me a beta of a firmware with tcpdump enabled and the command: tcpdump -i eth0 -w /tmp/wan0.pcap -s 1500
I sent them the file with the data and then they said:
"According to the information you provide, Our Enginner think it cause by RFC 4861 (https://tools.ietf.org/html/rfc4861) Section 4.2 Router Advertisement Message Format A: A lifetime of 0 indicates that the router is not to default router and SHOULD NOT appear on the default router list "
They made some changes to the firmware and they sent it to me, now IPv6 works correctly all the time, the funny thing is that in System log-> IPv6, WAN IPv6 Address: Always is empty
I told them that IPv6 was now working correctly with the modified firmware and they said:
"We use some workaround to deal with IPv6 Packet in your environment, it seems the ISP you used, IPv6 action didn't similar to most of ISP (after analysis the packet you provided), so we use this method."
But they do not know when the patch will be in the official firmware because according to them it is a problem that only happens with my ISP, I think it happens in more ISPs but the users have not noticed, firstly because IPv6 is disabled by default, and in the second because many ISPs are just beginning the IPv6 deployment, my ISP in 1 year went from 4% to 25% of IPv6 deployment.
Looking in the forum I see similar issues to mine (I think i´m not alone):
https://www.snbforums.com/threads/wan-ipv6-gateway-problem-fix.54199/
When IPv6 works the routing table shows the default route (WAN IPv6 Gateway), when IPv6 stops working the line with the default route (WAN IPv6 Gateway) disappears.
All this happens in official firmware. versions: 3.0.0.4.384.45149, 3.0.0.4.384.32799, I do not know if in previous versions it happens.
Also try the latest version of Asus merlin and the same thing happens.
(Excuse my language, my native language is Spanish)
Update 1:
My internet connection is VDSL2 50mbps down / 10mbps up.
My configuration is as follows: ISP -> Modem Huawei HG659 (In bridge mode) -> Asus RT-AC86U.
My ISP is DualStack (IPv4/IPv6), IPv6 Connection Type: Native with DHCP-PD
Update 2019-01-04:
After 1 month of testing, now I know when the problem occurs, when turning on the router for 31 minutes the devices in my network can access IPv6 sites (https://ipv6.google.com), the router can never reach IPv6 sites (probe from router GUI -> Network tools -> Network analisys -> Ping to ipv6.google.com)
After 31 minutes default route (WAN IPv6 Gateway) disappears.
Contact asus support and after several emails and tests they said:
"We found that the default gateway was removed caused by timeout occurred, we need to check if the router get the extended time packet"
And they sent me a beta of a firmware with tcpdump enabled and the command: tcpdump -i eth0 -w /tmp/wan0.pcap -s 1500
I sent them the file with the data and then they said:
"According to the information you provide, Our Enginner think it cause by RFC 4861 (https://tools.ietf.org/html/rfc4861) Section 4.2 Router Advertisement Message Format A: A lifetime of 0 indicates that the router is not to default router and SHOULD NOT appear on the default router list "
They made some changes to the firmware and they sent it to me, now IPv6 works correctly all the time, the funny thing is that in System log-> IPv6, WAN IPv6 Address: Always is empty
I told them that IPv6 was now working correctly with the modified firmware and they said:
"We use some workaround to deal with IPv6 Packet in your environment, it seems the ISP you used, IPv6 action didn't similar to most of ISP (after analysis the packet you provided), so we use this method."
But they do not know when the patch will be in the official firmware because according to them it is a problem that only happens with my ISP, I think it happens in more ISPs but the users have not noticed, firstly because IPv6 is disabled by default, and in the second because many ISPs are just beginning the IPv6 deployment, my ISP in 1 year went from 4% to 25% of IPv6 deployment.
Looking in the forum I see similar issues to mine (I think i´m not alone):
https://www.snbforums.com/threads/wan-ipv6-gateway-problem-fix.54199/
Last edited: