Why is my X1C causing my router to think it is getting a DDos attack?

Bambu Lab X1 Series Bambu Lab X1C
1

I just got the X1C and I just noticed that when I’m using it I start getting alerts from my Orbi router security that it is blocking DDOS attacks. only seems to happen when I’m using the printer. Any Ideas?

2

Might explain the problems people have been reporting with video feed jerkiness/stuttering with the latest update to Studio. The BBL servers might be polling the printer at too high a rate, making it look like a DDoS to your router.

1 Like
3

https://wiki.bambulab.com/en/general/printer-network-ports

Your Netgear tries to be smart (but isn’t) and interprets the UDP datagrams sent to the limited broadcast address (255.255.255.255) as a “DDOS attack”.

This is what I see in a packet capture:

tcpdump: verbose output suppressed, use -v[v]... for full protocol decode
listening on eth0, link-type EN10MB (Ethernet), snapshot length 262144 bytes
21:07:48.916938 IP 192.168.x.x.2021 > 255.255.255.255.2021: UDP, length 422
21:07:53.949921 IP 192.168.x.x.2021 > 255.255.255.255.2021: UDP, length 422
21:07:59.053418 IP 192.168.x.x.2021 > 255.255.255.255.2021: UDP, length 422
21:08:03.091542 IP 192.168.x.x.2021 > 255.255.255.255.2021: UDP, length 422
21:08:08.171203 IP 192.168.x.x.2021 > 255.255.255.255.2021: UDP, length 422

While I don’t know what it tries to discover, the frequency is definitely not a problem for any general purpose network device.

The fact that your Netgear reports a DDoS (first D stands for distributed) already gives you an idea that they can’t really know what they are doing. How is this distributed? Single source, low frequency!

So bottom line: Don’t worry and don’t take anything for granted your Netgear tells you, it might be correct but it might also be wrong. Netgear isn’t exactly a trusted brand for security gear IMHO. ubiquiti or mikrotik or maybe some other brands provide acceptable solutions for home use when it comes to security functionality but come at a higher price as well. This is still far from enterprise grade.

(I do get why one buys netgear, their wifi routers might work fine, but don’t get fooled into believing this 150 $ device can do everything)

Cheers and happy printing! :slight_smile: