[7.2] IPv6 WAN Routes not set correct after reboot

juliankr · Fri Apr 22, 2022 4:28 pm

Hello Guys,
i have serveral MT devices in service but at my sisters home I received a strange habbit.

The configuration is as follwed:
Site A (my home): DTAG Dual-Stack Internet Connection, severall IPIP Tunnels, OVPN Server Everything works well (RouterOS 6.49.6)
Site B (sisters home): Net-Dologne DS-lite Internet Connection. And this is a little bit complicated.... I found no way to get it working, using the AFTR-Address which is comming via an DHCP Option. Therefore we build up an IPIPv6 Tunnel (with IPSEC) to site A and route all the traffic through this tunnel.
This works fine, until the router on site B lost its connection or ist rebooted. Then nothing works. I got no traffic via IPv6 and therefore the tunnel is not build up.

My configuration:

[admin@MikroTik_Router0_EN] > /interface pppoe-client/print
Flags: X - disabled, I - invalid; R - running
 0  R ;;; PPPoE Einwahl auf VLAN10 NetCologne VDSL2
      name="pppoe-out1" max-mtu=auto max-mru=auto mrru=disabled
      interface=vlan1 user="xxxxx" password="xxxx"
      profile=default keepalive-timeout=10 service-name="" ac-name=""
      add-default-route=yes default-route-distance=10 dial-on-demand=no
      use-peer-dns=yes allow=pap

[admin@MikroTik_Router0_EN] /ipv6/dhcp-client> print detail
Flags: D - dynamic; X - disabled, I - invalid
 0    interface=pppoe-out1 status=bound duid="0x00030001dc2c6e42568c"
      dhcp-server-v6=fe80::b233:a6ff:fe91:fc3 request=prefix
      add-default-route=no use-peer-dns=yes rapid-commit=no dhcp-options=""
      pool-name="poolisp" pool-prefix-length=64  prefix-hint=::/0
      dhcp-options="" prefix=xxxx:xxxxx:xxxx::/48, 14h8m54s 

Flags: D - dynamic; X - disabled, I - inactive, A - active; c - connect, s - static, r - rip, b - bgp, o - ospf, d - dhcp, v - vpn, m - modem, y - copy; H - hw-offloaded; + - ecmp
   DAv   dst-address=::/0 routing-table=main gateway=pppoe-out1 immediate-gw=pppoe-out1 distance=10 scope=30 target-scope=10

   DAd   dst-address=xxxx:xxxx:xxxx::/48 routing-table=main gateway="" blackhole immediate-gw="" distance=1 scope=30 target-scope=10

   DAc   dst-address=xxxx:xxxx:xxxx::/64 routing-table=main gateway=bridge immediate-gw=bridge distance=0 scope=10

   DAc   dst-address=xxxx:xxxx:xxxx:1::/64 routing-table=main gateway=ipipv6-tunnel_IPv4 immediate-gw=ipipv6-tunnel_IPv4 distance=0 scope=10

   DAc   dst-address=xxxx:xxxx:xxxx:2::/64 routing-table=main gateway=pppoe-out1 immediate-gw=pppoe-out1 distance=0 scope=10

   DAc   dst-address=fe80::%ether2/64 routing-table=main gateway=ether2 immediate-gw=ether2 distance=0 scope=10

   DAc   dst-address=fe80::%bridge/64 routing-table=main gateway=bridge immediate-gw=bridge distance=0 scope=10

   DAc   dst-address=fe80::%pppoe-out1/64 routing-table=main gateway=pppoe-out1 immediate-gw=pppoe-out1 distance=0 scope=10

   DAc   dst-address=fe80::%vlan1/64 routing-table=main gateway=vlan1 immediate-gw=vlan1 distance=0 scope=10

After reboot, the pppoe-out1 Interface got a privat IPv6 Adrees (fe80...), but the DHCP-client is bound and received a prefix.
Fixing the problem is deficult. Some times disabling/enabling the dhcp-client is successfull, sometimes, I need to do this with the pppoe-out, sometime (and this is now the case!) i have to set add-default-route=no in the DHCP-client.
But after the nex reboot, it is possible that I have to enable this option again.
Is this a feature or a bug, or did I missconfigured something?
The Router on Site A ist configured in the same way and everything works.

I hope someone can help me,
Julian

Sob · Sun Apr 24, 2022 2:04 am

In fact, add-default-route=no in DHCPv6 client is correct, because DHCPv6 does not provide gateway at all. What this option does is that it simply uses address of DHCPv6 server as gateway, which sometimes works and sometimes doesn't. I don't have much experience with PPPoE and zero with PPPoE & IPv6, but it looks like the first route comes from it, so keep DHCPv6's add-default-route=no all the time and everything should (probably) work.

mkx · Sun Apr 24, 2022 12:33 pm

I don't have much experience with PPPoE and zero with PPPoE & IPv6, but it looks like the first route comes from it, so keep DHCPv6's add-default-route=no all the time and everything should (probably) work.

On one of my installations ISP provides service via PPPoE. Indeed setting add-default-route=no on DHCPv6 client (while having similar setting on PPPoE client enabled) is just fine, part of /ipv6 route print is

Flags: X - disabled, A - active, D - dynamic, C - connect, S - static, r - rip, o - ospf, b - bgp,
U - unreachable
 #      DST-ADDRESS              GATEWAY                  DISTANCE
 0 ADS  ::/0                     pppoe-out1                      1

while /ipv6 address print shows

Flags: X - disabled, I - invalid, D - dynamic, G - global, L - link-local
 #    ADDRESS                                     FROM-POOL INTERFACE                     ADVERTISE
11 DL fe80::e/64                                            pppoe-out1                    no

N.B. the router is running 6.49.5, so the output is slightly different, the settings should behave pretty similarly.

[7.2] IPv6 WAN Routes not set correct after reboot

[7.2] IPv6 WAN Routes not set correct after reboot

Re: [7.2] IPv6 WAN Routes not set correct after reboot

Re: [7.2] IPv6 WAN Routes not set correct after reboot

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