7.24rc [testing] is released!

[CGGXANNX]

@EdPa

• ipv6,ra - show warning about paused automatic RA on upgraded routers;

Ok, I think this change item implements the idea that @strods mentioned here:

7.23.2 [stable] is released!

Okay, thank you for all the information now. I am pretty sure the issue would be already resolved through support channel, but anyway - the problem is clear now. We will try to figure out if we can somehow differentiate "old config where option advertisement was not expected without additional configuration" from "new configuration where options must be advertised even without prefix configuration" and advertise options only if that is manually forced by "prefix" (including "none") configuration…

While this probably prevent the situation of accidental RA being sent on all interfaces after an upgrade from older versions, this is still less than ideal because:

• There is a red warning text over the entries that have "Advertise DNS" turned on from previous versions:

  

  Like all such warnings / errors, in the configuration export, a

  # automatic dns option advertising is not started, re-apply dns config
  

  comment will be included above the export entry, which is quite annoying.

• While we can easily remove this warning by making some edit to the entries, we might not want to do that for the entry with the all interface. There are configurations where this entry is useful and must stay enabled with the Advertise DNS also active, such as when we have to deal with dynamic interfaces from connecting VPN clients. But if we (accidentally) make edit to the all entry and the warning is gone then we'll have the issue with rogue RA coming from the router again.

I think it would be a better behavior if:

• RouterOS scraps the idea of handling "Advertise DNS" differently depending on whether the setting came from an upgrade or was manually set after 7.21.

• Instead, RouterOS keeps the behavior introduced with 7.23 (sending out RA even if there is no matching /ipv6 nd prefix entry) but only if the entry does not have interface=all, the entry must be set to a specific interface. If someone wants to advertise RA on a specific interface without prefix, they can always explicitly add a /ipv6 nd entry for that interface only.

• When the /ipv6 nd entry has interface=all, then RA is only sent out for an interface if there is an entry for that interface under /ipv6 nd prefix.

In short, the pre-7.23 behavior is kept specifically for the entry with interface=all only. No special handling must be done for the configurations coming from older versions. RA is only sent without prefix entry for an interface if there is an explicit /ipv6 nd entry for that interface. The all entry is not enough for that. The all entry only works for interfaces that also have /ipv6 nd prefix entries (including dynamic entries from dynamic interfaces).