Bonjour, 
Des nouvelles après quelques jours d'indisponibilité qui n'ont pas permis de constater une amélioration du problème.
Comme suggéré par Polo35230 dans le message #155, voici le copier/coller d'ifconfig :
Last login: Wed Mar 20 20:09:49 on console
jacquesgaullier@macbook-pro-de-ordinateur ~ % ifconfig
lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> mtu 16384
    options=1203<RXCSUM,TXCSUM,TXSTATUS,SW_TIMESTAMP>
    inet 127.0.0.1 netmask 0xff000000 
    inet6 ::1 prefixlen 128 
    inet6 fe80::1%lo0 prefixlen 64 scopeid 0x1 
    nd6 options=201<PERFORMNUD,DAD>
gif0: flags=8010<POINTOPOINT,MULTICAST> mtu 1280
stf0: flags=0<> mtu 1280
en3: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500
    ether ac:de:48:00:11:22 
    inet6 fe80::aede:48ff:fe00:1122%en3 prefixlen 64 scopeid 0x4 
    nd6 options=201<PERFORMNUD,DAD>
    media: autoselect (100baseTX <full-duplex>)
    status: active
ap1: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
    options=6463<RXCSUM,TXCSUM,TSO4,TSO6,CHANNEL_IO,PARTIAL_CSUM,ZEROINVERT_CSUM>
    ether 36:7d:da:2e:02:7f 
    inet6 fe80::347d:daff:fe2e:27f%ap1 prefixlen 64 scopeid 0x5 
    nd6 options=201<PERFORMNUD,DAD>
    media: autoselect
en0: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500
    options=400<CHANNEL_IO>
    ether 14:7d:da:2e:02:7f 
    inet 192.168.1.12 netmask 0xffffff00 broadcast 192.168.1.255
    media: autoselect
    status: active
awdl0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
    options=6463<RXCSUM,TXCSUM,TSO4,TSO6,CHANNEL_IO,PARTIAL_CSUM,ZEROINVERT_CSUM>
    ether 8e:d4:14:56:4b:ae 
    inet6 fe80::8cd4:14ff:fe56:4bae%awdl0 prefixlen 64 scopeid 0x7 
    nd6 options=201<PERFORMNUD,DAD>
    media: autoselect
    status: active
llw0: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500
    options=400<CHANNEL_IO>
    ether 8e:d4:14:56:4b:ae 
    inet6 fe80::8cd4:14ff:fe56:4bae%llw0 prefixlen 64 scopeid 0x8 
    nd6 options=201<PERFORMNUD,DAD>
    media: autoselect
    status: inactive
en2: flags=8963<UP,BROADCAST,SMART,RUNNING,PROMISC,SIMPLEX,MULTICAST> mtu 1500
    options=460<TSO4,TSO6,CHANNEL_IO>
    ether 82:38:64:64:54:00 
    media: autoselect <full-duplex>
    status: inactive
en1: flags=8963<UP,BROADCAST,SMART,RUNNING,PROMISC,SIMPLEX,MULTICAST> mtu 1500
    options=460<TSO4,TSO6,CHANNEL_IO>
    ether 82:38:64:64:54:01 
    media: autoselect <full-duplex>
    status: inactive
en5: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500
    options=6467<RXCSUM,TXCSUM,VLAN_MTU,TSO4,TSO6,CHANNEL_IO,PARTIAL_CSUM,ZEROINVERT_CSUM>
    ether 00:e0:4c:68:0a:a9 
    nd6 options=201<PERFORMNUD,DAD>
    media: autoselect (none)
    status: inactive
bridge0: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500
    options=63<RXCSUM,TXCSUM,TSO4,TSO6>
    ether 82:38:64:64:54:01 
    Configuration:
    id 0:0:0:0:0:0 priority 0 hellotime 0 fwddelay 0
    maxage 0 holdcnt 0 proto stp maxaddr 100 timeout 1200
    root id 0:0:0:0:0:0 priority 0 ifcost 0 port 0
    ipfilter disabled flags 0x0
    member: en1 flags=3<LEARNING,DISCOVER>
            ifmaxaddr 0 port 10 priority 0 path cost 0
    member: en2 flags=3<LEARNING,DISCOVER>
            ifmaxaddr 0 port 9 priority 0 path cost 0
    nd6 options=201<PERFORMNUD,DAD>
    media: <unknown type>
    status: inactive
utun0: flags=8051<UP,POINTOPOINT,RUNNING,MULTICAST> mtu 1380
    inet6 fe80::abd5:5c2d:4518:a284%utun0 prefixlen 64 scopeid 0xd 
    nd6 options=201<PERFORMNUD,DAD>
utun1: flags=8051<UP,POINTOPOINT,RUNNING,MULTICAST> mtu 2000
    inet6 fe80::4f4d:38c2:6521:8602%utun1 prefixlen 64 scopeid 0xe 
    nd6 options=201<PERFORMNUD,DAD>
utun2: flags=8051<UP,POINTOPOINT,RUNNING,MULTICAST> mtu 1000
    inet6 fe80::ce81:b1c:bd2c:69e%utun2 prefixlen 64 scopeid 0xf 
    nd6 options=201<PERFORMNUD,DAD>
utun3: flags=8051<UP,POINTOPOINT,RUNNING,MULTICAST> mtu 1380
    inet6 fe80::7c66:ac0d:b4a4:3f99%utun3 prefixlen 64 scopeid 0x10 
    nd6 options=201<PERFORMNUD,DAD>
utun4: flags=8051<UP,POINTOPOINT,RUNNING,MULTICAST> mtu 1380
    inet6 fe80::52bc:94c7:17:3f61%utun4 prefixlen 64 scopeid 0x11 
    nd6 options=201<PERFORMNUD,DAD>
jacquesgaullier@macbook-pro-de-ordinateur ~ %