Simply Services Cheat Sheet

This is a simple table which would list out commonly used services with a quick look. I’ve tried to sum-up service configuration at the basic level, so, this table would provide a quick look on packages required to start service, config files to be used, ports to be opened via firewall, command to check for syntax errors(if any) and commands to bring up service. This is not an exclusive information regarding configuring a service in Linux, but just a quick look sheet. Also note that I've tried to list out most commonly used services.

Simple Service Configuration Table
Service Name	Packages Required	Service To Be Started	Port(s) To Be Opened via Firewall	Main Configuration File(s)	Config Check Command (if any)
SSH (Secure Shell)	openssh-server { openssh, pam }	sshd (service sshd start)	22(tcp)	/etc/ssh/sshd_conf	sshd -t
VsFTP (Very Secure FTP	vsftpd { logrotate }	vsftpd (service vsftpd start)	21(tcp)	/etc/vsftpd/vsftpd.conf	vsftpd
NFS (Network File System)	nfs4-acl-tools & nfs-utils	rpcbind (service rpdbind start ) nfs (service nfs start) nfslock (service nfslock start)	2049(tcp) & 111(tcp)	/etc/exports	Any errors in /etc/exports file would be reported in /var/log/messages and also during service startup.
DNS (Domain Name System)	bind, bind-utils & bind-libs	named (service named start )	53 (tcp & udp)	/etc/named.conf /etc/resolv.conf Zone files:(example) /var/named/example.com.zone /var/named/example.com.revzone	service named configtest
DHCP (Dynamic Host Configuration Protocol)	dhcp	dhcpd (service dhcpd start )	68(tcp)	/etc/dhcp/dhcpd.conf	service dhcpd configtest
Apache (httpd)	httpd, mod_ssl	httpd ( service httpd start )	80(tcp) & 443 (tcp-ssl)	/etc/httpd/conf/httpd.conf	httpd -t OR apachectl configtest OR apachectl -t
SMB (Server Message Block)	samba, samba-client, samba-common	smb (service smbd start ) nmb (service nmbd start )	137 & 138 (udp) 139 & 445 (tcp)	/etc/samba/smb.conf	testparm
Mail Server - Postfix	postfix { openssl mysql-libs pcre }	postfix (service postfix start)	25 (tcp)	/etc/postfix/main.cf	postfix check
Mail Server - Sendmail	sendmail { procmail core-utils initscripts }	sendmail (service sendmail start)	25 (tcp)	/etc/mail/sendmail.cf	This could be checked in /var/log/maillog file. Otherwise, when starting the service it would display if any errors.
Proxy Server- Squid	squid { libtool-ltdl }	squid (service squid start )	3128(tcp) ( default port could be changed )	/etc/squid/squid.conf	Errors in config file would normally show up on service start.
NTP (Network Time Protocol)	ntp	ntpd ( service ntpd start)	123(udp)	/etc/ntp.conf	There is no specific option to check this, however, one could grep for "syntax error" in /var/log/messages file.
rsyslogd (Logging Daemon)	rsyslog { logrotate}	rsyslog (service rsyslog start)	514(tcp/ udp) (for remote logging )	/etc/rsyslog.conf /etc/sysconfig/rsyslog	Usually such errors would get logged in /var/log/message file and can be searched using key word { grep "CONFIG ERROR" /var/log/messages }
cups (Common UNIX Printing System)	cups	cups (service cups start)	631/(tcp/udp)	/etc/cups/cups.conf	Need to check logs under /var/log/cups/ (unless changed)

• For Red Hat variant systems.
• In RHEL7.x, need to use “systemctl start <servicename>” to start respective service.
• Respective ports needs to open in firewall unless it is turned off.
• These config files may change in other Linux variants such as Ubuntu, Debian etc.,
• Only main config files are listed out, there may be additional config files that needs to be configured based on needs.
• *under ‘packages required’ I’ve listed dependent package within curly braces.
• These configurations works perfect in RHEL6.x environment and it may slightly change in advanced versions.