RouterOS ignoring OSPF LSA with LA-bit set

RouterOS Forwarding Protocols
1

Hello,

in mailing list of Bird routing daemon https://bird.network.cz/pipermail/bird-users/2021-September/015758.html we discussed that RouterOS is wrongly ignoring OSPF LSAs with /128 IPv6 addresses with LA-option bit set.
In my situation, Debian server has IPv6 address attached to dummy interface. Bird correctly make LSA with following:

referenced-LS-type=Router LSA
referenced-LS-ID=0
prefix=2a02:6ca3:0:1::25/128 options=01000000 (LA)

However, this route never appear in RIB. According to RFC5340:

LA-bit
The “local address” capability bit. If set, the prefix is
actually an IPv6 interface address of the Advertising Router.
Advertisement of local interface addresses is described in
Section 4.4.3.9. An implementation MAY also set the LA-bit for
prefixes advertised with a host PrefixLength (128).

So does it mean that RouterOS does not understand “MAY implementation”
of LA-bit for host PrefixLength (128)? The same configuration with Quagga (which does not set LA bit) works correctly with Mikrotik.

2

This is old news, you can already find threads about it. It has been an issue for years. This has been fixed in RouterOS v7. They were unable to fix it in v6 for whatever reason. The workaround in v6 is to advertise that loopback route using redistribute connected on the origin router, then it is a type 5 LSA and does not have the LA bit set.