Some operating systems (eg. Linux kernel after 2.6.20) support a second protocol for SOCK_DGRAM, called UDP-Lite. If supported by your system, it would be enabled by providing IPPROTO_UDPLITE as the third argument to the socket() call. It is differentiated from normal UDP by allowing checksumming to be applied to only a portion of the datagram. … Read more
The maximum size of UDP payload that, most of the time, will not cause ip fragmentation is MTU size of the host handling the PDU (most of the case it will be 1500) – size of the IP header (20 bytes) – size of UDP header (8 bytes) 1500 MTU – 20 IP hdr – … Read more
Unfortunately, there is no 100% reliable way to perform NAT hole punching with UDP. At best, you can make some guesses about how NATs and firewalls will probably behave most of the time. But there will always be exceptions and they may not be rare. In this case, it sounds like you are using a … Read more
UDP is actually expected to work better than TCP in lossy networks (or congested networks). TCP is far better at transferring large quantities of data, but when the network fails it’s more likely that UDP will get through. (in fact, I recently did a study testing this and it found that SNMP over UDP succeeded … Read more
If you are using bash, you might as well write echo -n “hello” >/dev/udp/localhost/8000 and avoid all the idiosyncrasies and incompatibilities of netcat. This also works sending to other hosts, ex: echo -n “hello” >/dev/udp/remotehost/8000 These are not “real” devices on the file system, but bash “special” aliases. There is additional information in the Bash … Read more