
As is explained in MDEV-19893: Client reads from socket, gets the packet from 1. with seqno=0, which it does not expect, since seqno is supposed to be incremented. Client complains, throws tantrums and exceptions. To cater for clients that do not expect out-of-bound messages (i.e. server-initiated packets with seqno 0), all messages generated by MaxScale should use at least sequence number 1.