Lost Router Advertisements

RouterOS General
1

Hi all,

I have a problem with lost router advertisements on my Mikrotik WAP ac access point and I hope you can help me. :slight_smile:

I’ve set up an IPv6-only network for testing and wanted to make it available on my wireless network. Unfortunately clients don’t receive router advertisements and therefore don’t get an IPv6 address (there is no DHCPv6, just SLAAC).
I can see the clients sending router solicitations and the router receiving them and sending router advertisements. The AP is just bridging not routing, there is a VLAN trunk on ether1 and an 802.1x network on wlan1 and wlan2.
When I configure static addresses (IPv4/6) everything works fine.

This is the corresponding configuration

/interface bridge
add fast-forward=no name=bridge-vlan200

/interface vlan
add interface=ether1 name=vlan200-ether1 vlan-id=200
add interface=wlan1 name=vlan200-wlan1 vlan-id=200
add interface=wlan2 name=vlan200-wlan2 vlan-id=200

/interface bridge port
add bridge=bridge-vlan200 interface=vlan200-ether1
add bridge=bridge-vlan200 interface=vlan200-wlan1
add bridge=bridge-vlan200 interface=vlan200-wlan2

What could be the problem?
There is no IPv6 firewall on the AP.
I tested with an other AP (HPE) and everything works.

Best regards

2

Hi,
I had similar issue but using specific conditions - when I set short lifetime on RA prefixes then one host had often expired IPv6 addresses (although another repetitive RA should extend lifetime period). Issue was that affected host didn’t receive all broadcast/multicast frames it should and I discovered that when I turn off wifi power saving on client (on linux laptop, intel wifi), it start working.
I am not sure if this could be your case, but generally it could be some problems with delivery broadcast/multicast frames.
You can try fiddle with multicast-helper setting on your wireless interface.

3

Thank you very much!
I first thought, why multicast helpers in a single L2-Domain? But yes, this solves the problem.
I’ve set multicast-helper=full and now I receive the router advertisements.
And I will have a look at expired addresses :slight_smile:

Best regards

4

Those helpers work for both multicast and broadcast traffic … traffic which might get lost due to WiFi clients sleep mode. Multicast helpers transform those packets into unicast which are delivered in much more robust manner.