Objective

TCP and UDP are transportation protocols which are one of the core protocols of the Internet protocol suite. Both TCP and UDP work at the transport layer of the TCP/IP model, TCP uses a three way handshake to establish the reliable connection whereas UDP is unreliable but faster when compared to TCP. The network device offers some of the services which uses either TCP or UDP for easy management of the device. The services can be enabled or disabled based on the requirement.

The document explains how to enable or disable TCP/UDP services on Sx500 Series Stackable Switches.

Applicable Devices

- Sx500 Series Stackable Switches

Software Version

- v1.2.7.76

Setup TCP/UDP Services

Step 1. Log in to the web configuration utility and choose Security > TCP/UDP Services. The TCP/UDP Services page opens.

Step 2. Check the Enable check boxes to enable the respective TCP/UDP services. The available options are:

- HTTP Service — This is the protocol used to communicate with Web servers. It uses TCP.

- HTTPS Service — Stands for Hypertext Transfer Protocol Secure. This is similar to HTTP, but uses the TLS or SSL to encrypt and decrypt data, which makes it more secure than HTTP. It uses TCP.

- SNMP Service — Stands for Simple Network Management Protocol. This is used to manage devices on an IP network such as routers, switches, printers, etc. It usually uses UDP.

- Telnet Service — This is used to create a virtual terminal that communicates with a remote machine through the Internet as well as through the console. The communications made through Telnet are in plain text format. It uses TCP.

- SSH Service — Stands for Secure Shell. This is used to create a secure connection between two machines that are connected by an insecure network (often the Internet). This is similar to Telnet, but is more secure. The communications made through SSH are encrypted. It uses TCP.

Step 3. Click Apply.

The TCP Service Table displays the following fields for each service that are currently active:

- Service Name — Access method through which the switch offers the TCP service.

– SSH — Offers encrypted access to the command line of the switch.

– Telnet — Offers unencrypted access to the command line of the switch.

– HTTP — Offers unencrypted access to the web interface of the switch.

– HTTPS — Offers encrypted access to the web interface of the switch.

- Type — IP protocol the service uses.

– TCP — Offers a reliable connection between IPv4 hosts.

– TCP6 — Offers a reliable connection between both IPv4 and IPv6 hosts.

- Local IP Address — Local IP address through which the switch offers the service.

- Local Port — Local TCP port through which the switch offers the service.

- Remote IP Address — IP address of the remote device that requests the service.

- Remote Port — TCP port of the remote device that requests the service.

- State — Status of the service.

– Listening — Indicates that the switch is accepting connections for this Service on the Local Port.

– Established — Indicates an active connection.

– Time wait — Indicates a connection that has been closed, but is still being tracked so that out of order packets can still make it through the firewall.

The UDP Service Table displays the following fields for each service that are currently active:

- Service Name — Access method through which the switch offers the UDP service.

– SNMP — Offers unencrypted access to the command line of the switch.

– Bonjour — Offers unencrypted access to the command line of the switch.

- Type — IP protocol the service uses.

– TCP — Offers a reliable connection between IPv4 hosts.

– TCP6 — Offers a reliable connection between both IPv4 and IPv6 hosts.

- Local IP Address — Local IP address through which the switch offers the service.

- Local Port — Local UDP port through which the switch offers the service.

- Application Instance — The service instance of the UDP service. (For example, when two senders send data to the same destination).