IPv6 gateway marked as "down" after every reboot

[sff]

Hi all,

on my WAN I have public IPv4 and IPv6 addresses. Both are configured statically.
IPv4 works, but IPv6 never works after a reboot or after making any changes to the WAN interface (and applying those changes). Reason is that the IPv6 gateway is marked as "down".
After disabling and enabling the IPv6 gateway everything works fine until the next reboot or until applying any change to the WAN interface. After that: gateway gets marked as "down", disable, enable, and it's "up" again.

Any ideas for the reason or how to solve this? Because whenever the gateway should reboot I won't have IPv6 connectivity until I manually repair the IPv6 gateway...


Thank you,
 regards,
  Harry

[banym]

What version are you using?

If the gateway is marked down, are you able to ping it?

[sff]

Hi,

I'm on 20.7.1-amd64.

When I go to Interfaces, Diagnostics, Ping and enter the gateway address (fe80::1) I get "no route to host". But I get that too, when the gateway is "up" (although dpinger shows it as reachable with a RTT of 5ms). Which is weird - how is dpinger able to ping it?

[banym]

fe80 is mostly a private IPv6 local address range.

How is your IPv6 Setup.
Can you please show the interface configuration and network plan and futher information what you want to configure.

Normally your provider will assign you a prefix over dhcpv6 or for static configuration. This prefix is a officeal public IPv6 range. This needs to be configured to be able to route traffic correctly.

[Patrick M. Hausen]

Even for global unicast prefixes using a link-local address as the default gateway is fairly common. In our data center the gateway for each VLAN is fe80::<vlan-id>.

The one caveat is that on the host using this gateway you need to specify the scope since the link-local prefix is active on all interfaces. This is mandatory for your configured gateway as well as for ping6.

E.g. ping6 fe80::1%igb0

HTH,
Patrick

[sff]

Hi,
I attached the screenshot from what the provider told me (prefix, subnet size, gateway), what I configured in the interface and what the gateway looks like.

What I don't understand is why it works after disabling/enabling. So there can't be a general problem with the configuration, because it only does not work after doing changes to the interface or after rebooting.

I also attached the output from the ping.

About the fe80::1 gateway: I have a second machine running with the same provider (netcup.de), same infrastructure (just different IPs), which is running a Sophos UTM 9 - no problems at all... it just works. :/

Thank you for your help!

Regards,
 Harald

[Patrick M. Hausen]

For link-local addresses you must add a scope.

Do "ifconfig -a" to find the name of the physical interface with your assigned IPv6 address. Lets assume it is "igb0" or "em0" - the OPNsense UI can be a bit misleading because it assigns standard names like LAN, WAN, OPT1 ... to these interfaces. We need the physical interface as seen in FreeBSD.

Then do a `ping6 fe80::1%igb0` or whatever your interface name is. That should work! Please report back. We can then work from there ...

HTH,
Patrick

[sff]

Unfortunately it is not working although the gateway was marked as "up" during the time of this test (it also showed successful RTT).
The first output was made with "Source Address: WAN":

# /sbin/ping6 -S '2a03:4000:33:732::1' -c '3' 'fe80::1%vtnet0'
PING6(56=40+8+8 bytes) 2a03:4000:33:732::1 --> fe80::1%vtnet0
ping6: wrote fe80::1%vtnet0 16 chars, ret=-1
ping6: wrote fe80::1%vtnet0 16 chars, ret=-1
ping6: wrote fe80::1%vtnet0 16 chars, ret=-1

--- fe80::1%vtnet0 ping6 statistics ---
3 packets transmitted, 0 packets received, 100.0% packet loss
ping6: sendmsg: No route to host
ping6: sendmsg: No route to host
ping6: sendmsg: No route to host


This second test was done with "Source Address: Default":
# /sbin/ping6 -c '3' 'fe80::1%vtnet0'
PING6(56=40+8+8 bytes) fe80::487e:ceff:feec:3085%vtnet0 --> fe80::1%vtnet0
ping6: wrote fe80::1%vtnet0 16 chars, ret=-1
ping6: wrote fe80::1%vtnet0 16 chars, ret=-1
ping6: wrote fe80::1%vtnet0 16 chars, ret=-1

--- fe80::1%vtnet0 ping6 statistics ---
3 packets transmitted, 0 packets received, 100.0% packet loss
ping6: sendmsg: No route to host
ping6: sendmsg: No route to host
ping6: sendmsg: No route to host