Hi there,
I use my Mikrotik to establish a PPPoE connection to the internet, and my ISP sets an IPv4 lease time of 2 days. Then the IPv6 DHCP client gets a prefix that expires in 3 days. My IPv6 always works for a while, but after a few days (appears random but it's probably not) IPv6 connectivity on clients stops working. I always try to renew the IPv6 prefix and enable/disable the IPv6 address and reboot the clients, but it usually doesn't work. But rebooting the router and/or disabling/re-enabling the PPPoE connection fixes everything. So I suspect that what happens is every two days the PPPoE client gets a new IPv4 address, whereas the IPv6 client still has 1 day left on its lease, but it no longer works. I found the exact same issue here, and no solution was provided:
https://www.reddit.com/r/mikrotik/comme ... ver_pppoe/
Any tips? Thanks a lot.
Re: IPV6 over PPPoE prefix expiry longer than IPv4 lease
There is no "IPv4 lease time" in this case. PPPoE uses IPCP to give an IPv4 address. This address is allocated until the customer disconnects. The only way of shortening this period is by actually forcing a disconnect of the customer. Your ISP must be doing this every two days, and your DHCPv6 client is not automatically renewing the lease when this happens for whatever reason.
The main reason why some ISPs have a timeout for PPPoE connections is that if a customer fails to pay their bill and they remain connected via PPPoE at that time, their service won't be cut off because they haven't tried to authenticate again since the disconnection took place, and therefore they will continue to get service after the service cutoff because they simply never disconnected. A better way of handling this issue is for the ISP to configure their RADIUS server or billing system to send CoA packets to the NAS to force a customer disconnection when their bill is not paid, that is what we do to avoid a disconnection at an inopportune moment for the customer (ex. if they are watching Netflix or something exactly two days after their initial connection time).
The main reason why some ISPs have a timeout for PPPoE connections is that if a customer fails to pay their bill and they remain connected via PPPoE at that time, their service won't be cut off because they haven't tried to authenticate again since the disconnection took place, and therefore they will continue to get service after the service cutoff because they simply never disconnected. A better way of handling this issue is for the ISP to configure their RADIUS server or billing system to send CoA packets to the NAS to force a customer disconnection when their bill is not paid, that is what we do to avoid a disconnection at an inopportune moment for the customer (ex. if they are watching Netflix or something exactly two days after their initial connection time).
Re: IPV6 over PPPoE prefix expiry longer than IPv4 lease
Interesting, thanks for explaining that. And yes, my ISP's method is definitely inopportune, because it makes my VPN connection to my work drop every 2 days. So I've taken to resetting the PPPoE connection around midnight every so often so it doesn't interrupt me during the day.There is no "IPv4 lease time" in this case. PPPoE uses IPCP to give an IPv4 address. This address is allocated until the customer disconnects. The only way of shortening this period is by actually forcing a disconnect of the customer. Your ISP must be doing this every two days, and your DHCPv6 client is not automatically renewing the lease when this happens for whatever reason.
So is there anything I can do to force the DHCPv6 client to release and renew its lease whenever the PPPoE connection gets established?
Another possibly related bug with the DHCPv6 client is that it doesn't acquire a prefix immediately after the PPPoE connection comes up, it just hangs at "rebinding..." for about 10 minutes. This is case when disabling/re-enabling the PPPoE, or after rebooting the router. But as soon as I manually hit the "Apply" button the DHCPv6 client immediately acquires a prefix. This bug also affects other users, as described here:
viewtopic.php?t=122420
Re: IPV6 over PPPoE prefix expiry longer than IPv4 lease
You can maybe script it - under PPP->profiles you can define on-up and on-down scripts that should be run when PPPoE establishes a connection.So is there anything I can do to force the DHCPv6 client to release and renew its lease whenever the PPPoE connection gets established?
Another possibly related bug with the DHCPv6 client is that it doesn't acquire a prefix immediately after the PPPoE connection comes up, it just hangs at "rebinding..." for about 10 minutes. This is case when disabling/re-enabling the PPPoE, or after rebooting the router. But as soon as I manually hit the "Apply" button the DHCPv6 client immediately acquires a prefix. This bug also affects other users, as described here:
viewtopic.php?t=122420
And yes I have seen that issue before with the DHCPv6 client, not sure what the cause is, but it is annoying I agree.
Re: IPV6 over PPPoE prefix expiry longer than IPv4 lease
This is a known and very annoying problem indeed. Creating an on-up script under the PPP profile is the way to go. This is mine:You can maybe script it - under PPP->profiles you can define on-up and on-down scripts that should be run when PPPoE establishes a connection.
And yes I have seen that issue before with the DHCPv6 client, not sure what the cause is, but it is annoying I agree.
Code: Select all
:local interfaceName [/interface get $interface name];
:delay 10
:log info "profile-pppoe-isp client up: ipv6 dhcp-client release";
/ipv6 dhcp-client release [find interface=$interfaceName];Re: IPV6 over PPPoE prefix expiry longer than IPv4 lease
Excellent, thanks a lot to everyone for their replies.