>ДНС совершенно точно по очереди ай-пи отдает. При пинге видимо локальный кеш
>встревает. Из оф.документации на bind 9 (https://www.isc.org/software/bind/documentation/arm95):
The sortlist Statement
The response to a DNS query may consist of multiple resource records (RRs) forming a resource records set (RRset). The name server will normally return the RRs within the RRset in an indeterminate order (but see the rrset-order statement in the section called “RRset Ordering”). The client resolver code should rearrange the RRs as appropriate, that is, using any addresses on the local net in preference to other addresses. However, not all resolvers can do this or are correctly configured. When a client is using a local server, the sorting can be performed in the server, based on the client's address. This only requires configuring the name servers, not all the clients.
The sortlist statement (see below) takes an address_match_list and interprets it even more specifically than the topology statement does (the section called “Topology”).
То есть will normally return the RRs within the RRset in an _indeterminate_ order и The client resolver code should rearrange the RRs as appropriate. В более старых вроде да - по умолчанию Round Robin. А на счёт локального кеша - это да. Тут я так понимаю человек хочет, чтобы ip постоянно в одной последовательности были, поэтому вроде подходит для _этой_ цели sortlist.