After @hreintke 's fix (#8641 from #8308), this notice and these lwIP guidelines brought to attention by @mcspr,

our mDNS implementation will benefit from part or all these suggestions:

• ATTENTION: netif_set_up() now always has to be called, even when dhcp/autoip is used!
• LwipIntf::stateUpCB() should trigger also when IP address change