Questions tagged [udp]
User Datagram Protocol (UDP) is defined to make available a datagram mode of packet-switched computer communication in the environment of an interconnected set of computer networks. This protocol assumes that the Internet Protocol (IP) is used as the underlying protocol.
232 questions
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60 views
How to troubleshoot random latency spikes in WiFi traffic?
I am building an embedded device that runs Linux (Armbian) and receives a steady stream of UDP data. It has both Ethernet and WiFi connectivity. Ethernet works fine, however when using WiFi, the data ...
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0 votes
1 answer
58 views
Linux Off-path ICMP Fragmentation Needed Injection Attack to quic-go library
I was looking at CVE-2024-53259, where an attacker can inject ICMP Fragmentation Needed message to a host with QUIC connection using quic-go library. The cause is quic-go setting IP_PMTUDISC_DO socket ...
3 votes
2 answers
318 views
Why doesn't netcat print anything when listening in UDP mode when it can't reach the client even when the client can reach the server?
I'm using a fresh minimal Ubuntu server 24.04.1 LTS install. I run these commands as root to set up networking and do some experiments: apt install netcat-traditional ip netns add ns1 ip netns add ...
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0 votes
1 answer
248 views
Why isn't UDP port 443 accepting connections when iptables rules are set?
Why isn't UDP port 443 accepting connections when iptables rules are set? Environment Operating System: Linux 6.8.0-47-generic #47-Ubuntu, aarch64 Cloud VM: Yes (Hetzner) Current Setup I'm trying to ...
0 votes
0 answers
115 views
Send UDP data from one NIC and receive on another NIC on same machine
I have multiple NIC's on my Ubuntu machine. $ ifconfig docker0: flags=4099<UP,BROADCAST,MULTICAST> mtu 1500 inet 172.17.0.1 netmask 255.255.0.0 broadcast 172.17.255.255 inet6 ...
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2 votes
2 answers
527 views
traceroute (UDP) lost packets
I am facing the following issue when running traceroute between two nodes in the same subnet. This is done as a test whether the network connection between this 2 nodes is reliable or not. We were ...
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0 votes
1 answer
287 views
Difference between `net.core.rmem_default` and `net.core.rmem_max`
Are net.core.rmem_default and net.core.rmem_max both per socket or is one per socket and the other is for all sockets? This is also important since I use UDP, not TCP.
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0 votes
1 answer
467 views
iptables duplicate port traffic
I want to clone/duplicate all udp traffic incoming on port 8500 to port 8600. It is important that the source address is not modified. Also both ports must be accessible by applications (the packets ...
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