Hi
I just migrated from 1043nd+openwrt to ER-X. Everything goes well except IPv6 prefix issue which causing me LOTS OF PAIN!
My ISP changes IPv6 prefix every 72 hours via automatically disconnecting PPPoE. Once this happens, all devices under switch0 will lost IPv6 connection since they all use the OLD prefix. The only way to solve this is to restart (or physically re-plug) interface on my machines to regain IPv6 connectivity.
Frimware: 1.9.7, eth4 = wan+pppoe, switch0 = eth[0-3]
Here is reproducible steps:
1. First, confirm that PPPoE is connected and check both IPv4 and IPv6 address is working on PC/mac via: ping google.com , ping6 ipv6.google.com
2. ssh into ER-X, type: disconnect interface pppoe0 && sleep 5 && connect interface pppoe0
3. check IPv4 and IPv6 address is still working on PC/MAC via: ping google.com , ping6 ipv6.google.com. (at this point, IPv6 can't connect to other sites)
IPv4 is still working correctly but not IPv6. I can see PC/MAC obtains the new IPv6 address but still uses the old one as default, which breaks the IPv6connectivity. 
Really need to solve this, otherwise this issue will happen every 3 days
Possible solutions:
1. flash openwrt
2. Set a cronjob to restart ER-X every 3 days.
(both solutions are kinda stupid though)
My configuation:
firewall {
all-ping enable
broadcast-ping disable
ipv6-name WAN6_IN {
default-action drop
rule 10 {
action accept
description "Allow established/related"
state {
established enable
related enable
}
}
rule 20 {
action drop
description "Drop invalid state"
state {
invalid enable
}
}
rule 30 {
action accept
description "Allow ICMPv6"
log disable
protocol icmpv6
}
}
ipv6-name WAN6_LOCAL {
default-action drop
rule 10 {
action accept
description "Allow established/related"
state {
established enable
related enable
}
}
rule 20 {
action drop
description "Drop invalid state"
state {
invalid enable
}
}
rule 30 {
action accept
description "Allow ICMPv6"
log disable
protocol icmpv6
}
rule 40 {
action accept
description "Allow DHCPv6"
destination {
port 546
}
protocol udp
source {
port 547
}
}
}
ipv6-receive-redirects disable
ipv6-src-route disable
ip-src-route disable
log-martians enable
name WAN_IN {
default-action drop
description "WAN to internal"
rule 10 {
action accept
description "Allow established/related"
state {
established enable
related enable
}
}
rule 20 {
action drop
description "Drop invalid state"
state {
invalid enable
}
}
}
name WAN_LOCAL {
default-action drop
description "WAN to router"
rule 10 {
action accept
description "Allow established/related"
state {
established enable
related enable
}
}
rule 20 {
action drop
description "Drop invalid state"
state {
invalid enable
}
}
}
options {
mss-clamp {
interface-type all
mss 1440
}
}
receive-redirects disable
send-redirects enable
source-validation disable
syn-cookies enable
}
interfaces {
ethernet eth0 {
description Local
duplex auto
speed auto
}
ethernet eth4 {
description "Internet (PPPoE)"
duplex auto
pppoe 0 {
default-route auto
dhcpv6-pd {
no-dns
pd 0 {
interface switch0 {
host-address ::1
no-dns
service slaac
}
prefix-length 64
}
prefix-only
rapid-commit enable
}
firewall {
in {
ipv6-name WAN6_IN
name WAN_IN
}
local {
ipv6-name WAN6_LOCAL
name WAN_LOCAL
}
}
ipv6 {
address {
autoconf
}
dup-addr-detect-transmits 1
enable {
}
}
mtu 1480
name-server auto
password ****************
user-id 123456789@hinet.net
}
speed auto
}
loopback lo {
}
switch switch0 {
address 192.168.8.1/24
description Local
ipv6 {
address {
autoconf
}
dup-addr-detect-transmits 1
router-advert {
cur-hop-limit 64
link-mtu 0
managed-flag false
max-interval 600
other-config-flag false
prefix ::/64 {
autonomous-flag true
on-link-flag true
preferred-lifetime 259200
valid-lifetime 259200
}
reachable-time 0
retrans-timer 0
send-advert true
}
}
mtu 1500
}
}
protocols {
static {
interface-route6 ::/0 {
next-hop-interface pppoe0 {
}
}
}
}
service {
dhcp-server {
disabled false
hostfile-update disable
shared-network-name LAN {
authoritative enable
subnet 192.168.8.0/24 {
default-router 192.168.8.1
dns-server 168.95.192.1
dns-server 8.8.4.4
lease 86400
start 192.168.8.100 {
stop 192.168.8.131
}
}
}
use-dnsmasq disable
}
nat {
rule 5010 {
description "masquerade for WAN"
outbound-interface pppoe0
type masquerade
}
}Any suggestion would be really helpful. Thank you.
