server: mosquitto Socket error on client

[pat1]

enable debug messages on mosquitto and we get: gen 23 10:45:17 localhost.localdomain mosquitto[4046]: 1453542317: New connection from 127.0.0.1 on port 1883. gen 23 10:45:17 localhost.localdomain mosquitto[4046]: 1453542317: Socket error on client , disconnecting.

This is notable for : New connection from 127.0.0.1

[pat1]

It's monit that check the port and mosquitto activity

[pat1]

is not true:

ott 05 17:43:49 localhost.localdomain mosquitto[15050]: 1475682229: New client connected from 5.170.78.130 as 860719020206417 (c1, k60, u'pat1').
ott 05 17:43:49 localhost.localdomain mosquitto[15050]: 1475682229: Sending CONNACK to 860719020206417 (0, 0)
ott 05 17:43:49 localhost.localdomain mosquitto[15050]: 1475682229: Received SUBSCRIBE from 860719020206417
ott 05 17:43:49 localhost.localdomain mosquitto[15050]: 1475682229:         rpc/pat1/860719020206417/com (QoS 1)
ott 05 17:43:49 localhost.localdomain mosquitto[15050]: 1475682229: 860719020206417 1 rpc/pat1/860719020206417/com
ott 05 17:43:49 localhost.localdomain mosquitto[15050]: 1475682229: Sending SUBACK to 860719020206417
ott 05 17:43:49 localhost.localdomain mosquitto[15050]: 1475682229: Received PUBLISH from 860719020206417 (d0, q0, r1, m0, 'report/pat1/1000000,4400000/rmap/-,-,-/-,-,-,-/B01213', ... (12 bytes))
ott 05 17:44:53 localhost.localdomain mosquitto[15050]: 1475682293: Received PUBACK from 860719020206417 (Mid: 11075)
ott 05 17:45:39 localhost.localdomain mosquitto[15050]: 1475682339: Socket error on client 860719020206417, disconnecting.

1475682229 is the id of the GSM STIMA client