en:verejne:sit:ethernet

Cable connection

Members of Club Sincoolka can (besides WiFi) use a wired connection over Ethernet available in every room, specifically:

Sinkuleho dormitory: generally, all Ethernet sockets in your room should be working.
Dejvická dormitory: only two Ethernet sockets are working in each room.

If your device is registered, you'll be immediately connected to Internet straight away. If not, you should be redirected to our Information System - SINIS.

Your device needs to be registered to access our cable network. Please follow the instructions at Connect new device to the network.
WiFi registered devices are not automatically registered for Ethernet, as they are separate network interfaces with different MAC addresses!

Currently we only allow one Ethernet (cable-connected) device per user.

Also, if you need a cable, come to the LAB during office hours; we have a couple of them to give. ;)

Your cable-connected device has a public IPv4 address,
always use a properly configured firewall!
CESNET has decided to centraly block inbound connections to the UDP port 631 with regard to a serious vulnerability in CUPSd (CVE-2024-47176).

All devices connected with an Ethernet cable get not only an IPv6 address, but a public IPv4 address as well, it is therefore necessary to correctly configure the firewall on such devices. Alas, people do not, so, unfortunately, we had to close some ports that people commonly leave open by mistake:

Service Protocol Port
FTP TCP,UDP 20,21
Telnet TCP,UDP 23
SMTP TCP,UDP 25
DNS TCP,UDP 53
NetBIOS TCP,UDP 137,138,139
SMB (Samba) TCP,UDP 445
RDP (remote desktop) TCP,UDP 3389
Microsoft SQL TCP,UDP 1433,1434
OracleDB TCP 1521,1830
MySQL TCP 3306
PostgreSQL TCP 5432,5433
Memcached TCP,UDP 11211
MongoDB TCP 27017,27018,27019,28017
Redis TCP 6379
HP JetDirect/AppSocket/Raw/… (printing) TCP 9100
LPD/LPR (printing) TCP 515
IPP/CUPS (printing) TCP 631
UPnP TCP,UDP 1900,5000
SLP TCP,UDP 427
SNMP UDP 161,162
Other TCP,UDP 6666

If you need to have one of these ports open, please visit us during the office hours or send us an email.

A MAC address is an unique identifier of a network device. It is commonly written as a hexadecimal number, which may look for instance like this:

AB:CD:EF:12:A3:04 or AB-CD-EF-12-A3-04

If you are unable to find your device's MAC address, come visit us during office and bring your device with you, we are happy to help you. Sometimes, you may find it on the device itself, or it's packaging. On devices with menus, it's commonly found in sections called “Settings” or “About the device”.

  • en/verejne/sit/ethernet.txt
  • Last modified: 08.10.2024 11:28
  • by Karel Kopecký