This article explains the protocols you can select when setting up a firewall policy.

TCP: TCP (Transmission Control Protocol) is an essential part of the TCP/IP layer. TCP is connection-oriented and demands acknowledgement of receipt of every data packet sent. This protocol is designed to prevent loss of data, split the data stream of different applications and assign data packets. In addition, the protocol provides further functions:

  • Flow control: Flow control is a function adjusting the transfer speed of asynchronously operating end devices to the reception capacity of the receiving station.
  • Error handling: If an error occurs, the erroneous data segments are requested again by the higher layers.

UDP: UDP (User Datagram Protocol) is a connectionless transport protocol. It builds directly on the underlying IP protocol and is characterized by low latency.

TCP/UDP: This option has been created in the Cloud Server to facilitate the simultaneous activation of the TCP and UDP protocols.

ICMP: ICMP (Internet Control Message Protocol) is a protocol for transferring status information and error messages in the IP, TCP and UDP protocols. This protocol is part of the IP protocol, but is treated as a separate protocol.

IPsec: IPsec (Internet Protocol Security) is a protocol suite to protect communications over TCP / IP networks. This protocol suite includes encryption and authentication mechanisms intended to ensure the integrity, authenticity and confidentiality of data transfers.

GRE: The GRE protocol (Generic Routing Encapsulation) is a standard for tunneling. Using the GRE protocol, packets of any protocol can be encapsulated within another protocol and transported through tunnels.


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