I unmark as solution because I still have connextion lost on ssh or sftp connection resetted by pear.
as I was sftp on bananapi A :
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
link/ether a6:b7:fd:ec:f9:87 brd ff:ff:ff:ff:ff:ff permaddr 42:ba:c9:a3:fb:27
inet 192.168.0.8/24 brd 192.168.0.255 scope global dynamic noprefixroute eth0
valid_lft 3527sec preferred_lft 3527sec
inet6 2a03:d604:11d:eb00:d3d2:c282:7a9d:4f13/64 scope global temporary dynamic
valid_lft 1772sec preferred_lft 1772sec
inet6 2a03:d604:11d:eb00:117e:6a5f:abb2:3551/64 scope global temporary dynamic
valid_lft 1769sec preferred_lft 1769sec
inet6 2a03:d604:11d:eb00:309d:695d:62d6:df0f/64 scope global temporary dynamic
valid_lft 1766sec preferred_lft 1766sec
inet6 2a03:d604:11d:eb00:1409:19fb:20c8:1ac1/64 scope global temporary dynamic
valid_lft 1763sec preferred_lft 1763sec
inet6 2a03:d604:11d:eb00:15dd:e03:244e:a87f/64 scope global temporary dynamic
valid_lft 1760sec preferred_lft 1760sec
inet6 2a03:d604:11d:eb00:ed97:1274:60af:cc6d/64 scope global temporary dynamic
valid_lft 1757sec preferred_lft 1757sec
inet6 2a03:d604:11d:eb00:6156:e51d:b46e:5c0a/64 scope global temporary dynamic
valid_lft 1754sec preferred_lft 1754sec
inet6 2a03:d604:11d:eb00:c214:5a77:88bc:d990/64 scope global temporary dynamic
valid_lft 1751sec preferred_lft 1751sec
inet6 2a03:d604:11d:eb00:878f:9f50:14a3:19d9/64 scope global temporary dynamic
valid_lft 1748sec preferred_lft 1748sec
inet6 2a03:d604:11d:eb00:c832:7bcb:4b50:be2e/64 scope global temporary dynamic
valid_lft 1745sec preferred_lft 1745sec
inet6 2a03:d604:11d:eb00:f345:d4f2:1b5b:9a8e/64 scope global temporary dynamic
valid_lft 1742sec preferred_lft 1742sec
inet6 2a03:d604:11d:eb00:e358:706d:16ee:1425/64 scope global temporary dynamic
valid_lft 1739sec preferred_lft 1739sec
inet6 2a03:d604:11d:eb00:8a71:2d3c:f2f9:58a0/64 scope global temporary dynamic
valid_lft 1736sec preferred_lft 1736sec
inet6 2a03:d604:11d:eb00:45e7:778b:3b13:5824/64 scope global temporary dynamic
valid_lft 1733sec preferred_lft 1733sec
inet6 2a03:d604:11d:eb00:e733:197d:7a82:b7b8/64 scope global temporary dynamic
valid_lft 1730sec preferred_lft 1730sec
inet6 fe80::a4b7:fdff:feec:f987/64 scope link dadfailed tentative
valid_lft forever preferred_lft forever
it was switched to bananapi B,
eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
link/ether a6:b7:fd:ec:f9:87 brd ff:ff:ff:ff:ff:ff
inet 192.168.0.18/24 brd 192.168.0.255 scope global noprefixroute eth0
valid_lft forever preferred_lft forever
inet 192.168.0.8/24 brd 192.168.0.255 scope global secondary dynamic noprefixroute eth0
valid_lft 2282sec preferred_lft 2282sec
inet6 2a03:d604:11d:eb00:affa:b0a3:12b8:9d8e/64 scope global temporary dynamic
valid_lft 3598sec preferred_lft 3598sec
inet6 2a03:d604:11d:eb00:d0d9:743b:d37c:be87/64 scope global temporary deprecated dynamic
valid_lft 3598sec preferred_lft 0sec
inet6 2a03:d604:11d:eb00:a4b7:fdff:feec:f987/64 scope global dynamic mngtmpaddr
valid_lft 3598sec preferred_lft 3598sec
inet6 fe80::a4b7:fdff:feec:f987/64 scope link
valid_lft forever preferred_lft forever
when I uploaded a thing on A it put the file on B, it is a complete mess of IP table, @igor, it seems even like a IPV6 table flooding !
This is a big issue, IPV6 interfers with IPV4 ! IMAC adresses from A and B are the same here , shoul'nt be unique as based on the constructor network card?
18.0-168-192.rev (192.168.0.18) at a6:b7:fd:ec:f9:87 [ether] on enp11s0
8.0-168-192.rev (192.168.0.8) at a6:b7:fd:ec:f9:87 [ether] on enp11s0