UDP ports use the Datagram Protocol. Like TCP, UDP is used in combination with IP (the Internet Protocol) and facilitates the transmission of datagrams from one computer to applications on another computer, but unlike TCP, UDP is connectionless and does not guarantee reliable communication; it's up to the application that received the message
TIME can operate over either TCP or UDP. When operating over TCP, a host connects to a server that supports the TIME protocol on TCP port 37. The server then sends the time as a 32-bit unsigned binary number in network byte order representing a number of seconds since 00:00 (midnight) 1 January, 1900 GMT and closes the connection. Oct 18, 2013 · The default instance would listen on TCP port 1433, while the other named instances could listen on TCP ports 1434 and 1954, respectively. The network administrator would then configure the firewall to forward network requests for UDP port 1434 and TCP ports 1433, 1434, and 1954 on that IP address. The phone works fine. However, I reran the basic port scan (again troubleshooting issue with access) and found that the UDP Port 123 is now open but now UDP Port 53 is blocked. UDP Port 53 handles DNS? To my knowledge, the new router is not blocking UDP 53. Here's a twist; when I run the Advanced scan Both UDP Ports 53 and 123 are blocked. Jan 17, 2012 · The command that enabled the listening of udp 123 was the "ntp server [server address]" command. I think what you said about NTP clients "shall not" listen to udp 123 isn't correct. In Cisco IOS as soon as you configure an ntp server to get time from, the device starts listening on udp 123. Netbios TCP - Port 139 Netbios TCP - Port 138 NTP TCP and UDP - Port 123. Step 5: Join the remote server to the domain. You'll now have the path setup between the two into my linux server (Ubuntu 8) I have top open the port 123 for ntp. I have write this into /etc/iptables.rules::INPUT ACCEPT [7496:9080183] :FORWARD ACCEPT [0:0] :OUTPUT ACCEPT [4393:322232] [0:0] -A INPUT -p udp -m udp --sport 8100 -j ACCEPT [0:0] -A INPUT -p udp -m udp --dport 8100 -j ACCEPT [0:0] -I INPUT -p udp --dport 123 -j ACCEPT [0:0] -I OUTPUT -p udp --sport 123 -j ACCEPT COMMIT
UDP Port 123 may use a defined protocol to communicate depending on the application. A protocol is a set of formalized rules that explains how data is communicated over a network. Think of it as the language spoken between computers to help them communicate more efficiently.
into my linux server (Ubuntu 8) I have top open the port 123 for ntp. I have write this into /etc/iptables.rules::INPUT ACCEPT [7496:9080183] :FORWARD ACCEPT [0:0] :OUTPUT ACCEPT [4393:322232] [0:0] -A INPUT -p udp -m udp --sport 8100 -j ACCEPT [0:0] -A INPUT -p udp -m udp --dport 8100 -j ACCEPT [0:0] -I INPUT -p udp --dport 123 -j ACCEPT [0:0] -I OUTPUT -p udp --sport 123 -j ACCEPT COMMIT
Aug 27, 2019 · TCP/UDP: Remote Procedure Call (RPC) 1057, 1831: sunrpc: Portmap (sunrpc) 113: TCP: Identification Protocol: 1413: ident — 119: TCP: Network News Transfer Protocol (NNTP) 3977: nntp: Apps that read newsgroups. 123: UDP: Network Time Protocol (NTP) 1305: ntp: Date & Time preferences, network time server synchronization, Apple TV network time
The phone works fine. However, I reran the basic port scan (again troubleshooting issue with access) and found that the UDP Port 123 is now open but now UDP Port 53 is blocked. UDP Port 53 handles DNS? To my knowledge, the new router is not blocking UDP 53. Here's a twist; when I run the Advanced scan Both UDP Ports 53 and 123 are blocked.