Transmission Control Protocol (TCP)

wikipedia:Transmission Control Protocol

• netstat -tn or netstat --tcp -n

• TCP checksum: ethtool --show-offload eno0

List os TCP ports

• 111 port mapper (rpc.portmap or just portmap, or rpcbind)
• TCP port 587, is the default mail submission port (RFC4409).
• TCP port 1433 (Microsoft SQL server)
• 2181 Apache Zookeeper
• TCP port 2707 mongoDB
• 3000 Rocket.Chat and Grafana
• 3389 RDP
• 4501 IPsec
• 5044 Standard port in Filebeats/Logstash implementation of Lumberjack protocol
• 5060 Session Initiation Protocol (SIP)
• 5439 PostgreSQL
• 5439 Amazon Redshift
• 5601 Kibana
• 5672 RabbitMQ
• 5938 TeamViewer
• 8089 Splunk
• 9000 minIO
• 9090 Prometheus
• 9100 Prometheus-node-exporter
• 10050 Zabbix
• 10051 Zabbix
• 10250 Kubelet

Activities

• Check TCP connectivity: nping --tcp, check_tcp (Nagios)
• Read about TCP Fast Open
• Learn about route command
• Learn about wikipedia:TCP congestion control
• TCP Fast Open, Linux kernel 3.7

Related terms

• Multipath TCP (MPTCP)
• Vint Cerf and Bob Kahn
• /proc/sys/net/ipv4/tcp_rmem

See also

• IP: route, mtr, traceroute, tcptraceroute, lft, TTL
• ip [link, route], ifconfig netstat ss lsof ping ethtool mii-tool arping nmcli(RHEL) route networkctl, netplan, tc
• TCP/IP, Transport protocol, UDP, SCTP, QUIC, subnet mask, Routing protocols: BGP, routing table, Policy based routing, multicast, TCP Fast Open, RDP, TTL, RTT, MPTCP, Large send offload (LSO): (TSO, GRO, GSO, TCP checksum), ethtool, SCTP, 5-Tuple, Check TCP connectivity, TCP window size, /proc/sys/net/ipv4/tcp_rmem, ack, List of TCP ports, localhost, broadcast address
• Networking: bandwidth, latency, Jitter, Ethernet, UPnP, MPLS, Frame Relay, ATM, TCP/IP, ARP, WiFi, BGP, Networking timeline, Router, Proxy ARP, Services & Networking, Traffic shapper