Category of servers:
Standalone servers
- A daemon or service can run in standalone mode
Category of servers:
inetd / xinetd
Name:
internet service daemon
extended internet service daemon
- dependent on another service to be activated
Category of Mailing servers:
Mail Servers
- Sendmail is the standard mail server program or Mail Transport Agent for UNIX platforms
- Qmail is another mail server
Category of Mailing servers:
Remote mail servers
- The most popular protocols to access mail remotely are POP3 and IMAP4.
- IMAP and POP both allow offline operation, remote access to new mail
- both rely on an SMTP server to send mail.
Category of Mailing servers:
Mail user-agents
- Unix text and graphical e-mail clients
Category of Web servers:
The Apache Web Server
- most popular web server
- modular design
- SSL support
- stability
- speed.
Config files:
- server config dir: /etc/httpd
- server config file: httpd.conf
Category of Web servers:
Web browsers
eg.
Netscape Navigator, Firefox
Category of Proxy servers:
- Forward proxy
- Reverse proxy
Proxy configurations:
- http_proxy
- ftp_proxy
In ~/.bashrc
Categories of FTP:
FTP servers
- FTP server is typically run from xinetd, using the WU-ftpd server
Categories of FTP:
FTP clients
ncftp command
- improved version of the common UNIX ftp command
- offers extra features such as a nicer and more comprehensible user interface, file name completion, append and resume functions, bookmarking, session management
Domain Name System servers
- all applications need DNS services to match IP addresses to host names.
- A DNS server networks with other DNS server to query and find unknown addresses
client config file:
- /etc/resolv.conf
determining Domain Name Servers are contacted in which order
DHCP Servers
Functions:
- Dynamically configuring a device with dynamic IP
- 3 players: IP addresses, subnet mask, default gateway
- DHCP pool configures a DHCP server to hand out IP addresses.
- pool of addresses is a range of consecutive numbers within a single IP subnet.
- subnet mask tells devices how large the subnetwork is that they are connected to (reference to Cloudflare documentation)
- default gateway is the IP address that signifies the exit point of the subnetwork to which the device belongs
Authentication services:
Tradition
- information stored in /etc/passwd, /etc/shadow for local authentication
Authentication services:
Pluggable Authentication Module(PAM)
Cofig files:
- /etc/pam.d
- /etc/pam.conf
LDAP Servers
Name:
Lightweight Directory Access Protocol
- client-server system for accessing globla or local directiories
Linux using OpenLDAP:
- slapd: a stand-alone server
- slurpd: a stand-alone LDAP replication server
- libraries: implementing the LDAP protocol
