reconnect from a ban with same IP how?

[Blue_Pr!nt]

Dec 11 03:34:45 [188.220.239.21] client BluePr!nt|BC| called a vote: ban player Teh54, reason: GTFO
Dec 11 03:34:45 [88.163.251.84] disconnecting client Teh54 (vote-banned from the server) cn 2, 28 seconds played, score saved
Dec 11 03:34:50 [88.163.251.84] client connected
Dec 11 03:34:50 [88.163.251.84] disconnecting client Teh54 (connection refused - you have been banned from this server) cn 2, 0 seconds played
Dec 11 03:34:52 [] >1$U<kaBOOM gibbed Miyagui
Dec 11 03:34:54 [] client connected
Dec 11 03:34:54 [] Ashley logged in (default), AC: 1104|840
Dec 11 03:34:55 [] +sCr3W+ParK0uR says: 'Go get 'em boys!'
Dec 11 03:34:58 [] +sCr3W+ParK0uR says: 'We did it!'
Dec 11 03:34:59 [] disconnected client Miyagui cn 4, 188 seconds played, score saved
Dec 11 03:35:00 [] ITCHI-BATI-SAN gibbed >1$U<kaBOOM
Dec 11 03:35:02 [] >1$U<kaBOOM says: 'ns'
Dec 11 03:35:03 [] +sCr3W+ParK0uR says: 'We did it!'
Dec 11 03:35:05 [88.163.251.84] client connected
Dec 11 03:35:05 [88.163.251.84] Teh54 logged in (default), AC: 1103|840
Dec 11 03:35:12 [88.163.251.84] Teh54 says: '?????????'
Dec 11 03:35:12 [] +sCr3W+ParK0uR gibbed >1$U<kaBOOM
Dec 11 03:35:18 [] >1$U<kaBOOM says: 'how he come backl'
Dec 11 03:35:22 [] +sCr3W+ says: 'hackkkk'

Teh54 used the same IP yet, was able to reconnect in less then a minute. he done this various times..
how is this possible with no IP change?