Describing the Client Server Model

Describing the Client Server Model


inetd -- (Internet Service Daemon) Responsible for On-Demand services eg. Telnetd, ftpd
/etc/inetd.conf -- Config file for inetd daemon

To turn-off a service, add a symbol to the beginning of the corresponding to that service in the /etc/inet.conf file, and send a HUP request.
# pkill –HUP inetd -- Restarting the inetd services

/etc/inet/services -- Services file
/etc/inet/protocols -- Registered protocols are listed here

Network Ports -- Well-known ports & ephemeral (short-lived) ports
Port Assignment -- Central Authority (Well-known) & Dynamic Binding (ephemeral)

Central Authority Ports -- 0 – 1024
Dynamic Binding -- 1024 – 65000

Starting Services that use a Well-Known Port
1. Services that start by default at system boot time (eg. Sendmail)
2. Services start on-demand (eg. telnet)

Starting RPC Services
1. Services that start by default at system boot time
2. Services start on-demand

The rpcbind process (Daemon) associates RPC program numbers with port numbers. /etc/rc2.d/S71rpc script initializes the rpcbind service (port 111)
rpcbind - 111 port number - Resposible for rpc services
/etc/rpc -- Config file for rpc services

# grep rpcbind /etc/services
sunrpc 111/udp rpcbind
sunrpc 111/tcp rpcbind

# rpcinfo –p -- rpcbind information
Prog No Version Protocol Port Service Name
# rpcinfo –d 1002(Prog No) 1(Version) -- Deleting RPC service registration