PPPOE no default route for IPv6 only IPv4

RouterOS General
1

Hey there, looking for a little help with IPv6.

My ISP offers dual stack with DHCPv6 PD over PPPOE. This works fine, however every time I connect the PPPOE interface, I need to manually remove the automatically added default route for IPv6, otherwise it won’t work when the correct default route is added by the DHCPv6 client. Is it possible to have a default route only for IPv4 but not for IPv6?

2

Instead of using ‘Add default route’ in the PPPoE client interface settings you could add a static default route for IPv4 only

/ip route
add distance=1 gateway=YOUR_PPPOE_INTERFACE_NAME
3

Thanks, I’ll see if that works, but I’m still not sure why this can’t be set independently for IPv4 and IPv6. I already tried increasing the distance for the automatically added entry but that didn’t work unfortunately.

4

It seems that your PC hasn’t got the gateway. I suggest you type the gateway manually and then test the issue.

Open “Network and Sharing center” > “Change adapter settings”. Then right click the adapter which you used, and click “Properties” > double click "Internet Protocol Version 4 (TCP/IPV4). After that, you could type your IP address and gateway manually.

5

The issue is not with a PC (I don’t have any PC-s anyway :slight_smile:) and not with IPv4; the problem is when you establish the PPPOE connection with the “Add default route” option enabled, it creates a default route for both IPv4 and IPv6, however I get the IPv6 default route when I start the DHCPv6 client on the same interface, so I end up with 2 default routes for v6 (::0) and my v6 connections don’t work until I delete the one created by the PPPOE connection and leave only the DHCPv6 default route.

6

It seems to depend on how ISP configures their PPPoE server. In my case I have two (relevant) routes:

/ipv6 route print detail

 0 ADS  dst-address=::/0 gateway=pppoe-out1 gateway-status=pppoe-out1 reachable 
        distance=1 scope=30 target-scope=10 

 1  DS  dst-address=::/0 gateway=fe80::230:88ff:fe04:98c5%pppoe-out1 
        gateway-status=fe80::230:88ff:fe04:98c5%pppoe-out1 reachable distance=1 
        scope=30 target-scope=10

The first one is (my guess) result of DHCPv6 client, the second one is result of PPPoE client (I have add-default-route=yes in both DHCPv6 and PPPoE clients). And in my case they don’t interfere with each other as the second one is referring to link-local addresses and only defines “next hop”. I guess that if ISP uses global address in PPPoE settings and you’re using DHCPv6-provided default route as well, then this might not work as desired.

7

Your first seems sourced from PPPOE and your second is inactive - wonder how it works for you at all :slight_smile: but if it’s inactive it won’t interfere.