Synology Used Ports

Synology has a Knowledge Base entry on which ports are used: What network ports are used by Synology services?

Application/Service	Protocol	Port
FTP	TCP	20, 21, 55536, 55537
SSH	TCP	22
Telnet	TCP	23
SMTP	TCP	25
DNS	Both	53
DHCP	UDP	67-68
TFTP	TCP	69
HTTP	TCP	80
Kerberos	TCP/UDP	88
Mail	TCP	110
NFS	TCP	111, 892, 2049
NTP	TCP	123
High Availability	Both	123, 874, 5405, 5406, 7400-7999
CIFS	TCP	137-139, 445
IMAP	TCP	143
SNMP	TCP	161
LDAP	TCP	389
HTTPS	TCP	443
Kerberos	TCP/UDP	464
SMTPS	TCP	465
IPSEC	UDP	500, 4500
Syslog	TCP/UDP	514
LPR Print	TCP	515
DHCPv6	UDP	546,547
AFP	TCP	548
IPP Print	TCP	631
LDAP/SSL	TCP	636
RSync	TCP	873
IMAPS	TCP	993
POPS	TCP	995
OpenVPN	UDP	1194
High Availability (HA)	TCP/UDP	1234
Synology Assistant	TCP/UDP	1234
IPSEC	TCP	1701
PPTP	TCP	1723
RADIUS Server	UDP	1812
UPnP	UDP	1900
Proxy Server	TCP	3128
MFP Print	TCP	3240-3259
iSCSI	TCP	3260, 3263, 3265
LUN Backup	TCP	3260
Snapshot Replication	TCP	3261, 5566
MySQL	TCP	3306
Presto File Server	TCP/UDP	3360, 3361
UPS	TCP	3493
iTunes	TCP	3689
SVN	TCP	3690
CIFS Scale-out Cluster	TCP	4279, 17909, 17913, 19998, 24007, 24008, 24009-24045, 38465-38501,
eMule	TCP	4662
eMule	UDP	4672
DSM	TCP	5000-5001
Video Station	TCP	5002, 5004, 9025-9040, 65001
WebDAV, CalDAV	TCP	5005-5006, 38008, 38443
Bonjour	TCP	5353
High Availability (HA)	TCP/UDP	5405, 5406
Active Backup for Business	TCP	5510, 5985, 5986
CardDAV	TCP	5555
SMI-S Provider	TCP	5988, 5989
AirPlay	UDP	6001-6010
AirPlay	TCP	6011-6030
Hyper Backup	TCP	6281
Drive Server	TCP	6690
BiTorrent	UDP	6881
File Station	TCP	7001
Migration Assistant	TCP/DRBD	7400-7499
High Availability (HA)	TCP/UDP	7400-7499
C2 Identity Edge-Server	TCP	7712
Download Station	TCP	8001
CardDAV Server	TCP	8008, 8443
Audio Station	TCP	8801
Logitech Media Server	TCP	9002, 3483
Surveillance Station	TCP	9900-9901, 19997-19998
Synology Assistant	TCP/UDP	9997-9999
Data Replicator	TCP	9997-9999
BiTorrent	TCP	16881
Radius	TCP	18120
Visual Station	UDP	19999
DLNA	TCP	50001-50002
SSDP	UDP	55900-55910
????	UDP	4000