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Knowledge document #249
FRITZ!Box 4020
This support document is available for the following products:
- FRITZ!Box 7690
- FRITZ!Box 7590 AX
- FRITZ!Box 7590
- FRITZ!Box 7583 VDSL
- FRITZ!Box 7583
- FRITZ!Box 7582
- FRITZ!Box 7581
- FRITZ!Box 7560
- FRITZ!Box 7530 AX
- FRITZ!Box 7530
- FRITZ!Box 7520
- FRITZ!Box 7510
- FRITZ!Box 7490
- FRITZ!Box 7430
- FRITZ!Box 7390
- FRITZ!Box 7360
- FRITZ!Box 6890 LTE
- FRITZ!Box 6850 5G
Firewall reports attacks on TCP port 80 or 53805 or unsolicited packets of type 0x88e1
This guide deals with the following issues:
- A firewall on a computer in the FRITZ!Box home network reports regular attacks ("Syn Flood", "Denial of Service (DoS)") on TCP port 80, 53805, or a different port between 50001 and 59999.
- Every five seconds, a firewall or an application for analyzing network connections such as Wireshark reports packets of type 0x88e1 (EtherType).
Connections do not pose a security threat
The incoming connections do not come from the internet, they come from the FRITZ!Box and do not pose a security threat.
- TCP Port 80:
The FRITZ!Box uses TCP port 80 to check regularly whether computers or other devices connected to the FRITZ!Box offer web services accessible over HTTP, such as a user interface. The web services of these devices can be accessed directly under "Home Network > Mesh" in the FRITZ!Box user interface. - TCP port 53805 (or another port between 50001 and 59999):
The FRITZ!Box uses TCP port 53805 or a different randomly selected port between 50001 and 59999 to check regularly whether there are other FRITZ!Box models, FRITZ!Repeaters, or FRITZ!Powerline adapters in the home network that are compatible with Mesh. Any such devices it finds are displayed in the FRITZ!Box user interface under "Home Network > Mesh". - Type 0x88e1:
The FRITZ!Box uses packets of EtherType 0x88e1 to check regularly whether there are any FRITZ!Powerline adapters in the home network. Any adapters it finds are displayed in the FRITZ!Box user interface under "Home Network > Mesh".
Note:If you do not want to receive these messages any more, configure the device's firewall to allow incoming connections to the respective port or packets of type 0x88e1. Refer to the manufacturer of the firewall for information on how to set it up, for example consult the manual.