Internet Services
Geoffrey D. Bennett

- Web
- FTP
- Email
- POP

Services
--------

Configuring services for boot time:

- Check all services:

  /sbin/chkconfig --list

- Check one service:

  /sbin/chkconfig --list httpd

- Turn a service on or off:

  /sbin/chkconfig httpd on
  /sbin/chkconfig httpd off

(for xinetd-based services, changes made by chkconfig take effect
immediately, presuming that xinetd is running)

Starting/stopping services now:

- Check one service:

  /sbin/service httpd status

- Check all services:

  ps auxw
  netstat -tunap

- Start, stop, restart, reload:

  /sbin/service httpd start
  /sbin/service httpd stop
  /sbin/service httpd restart
  /sbin/service httpd reload

Web
---

Package name: httpd
Service name: httpd

Configuration:

- Main configuration file: /etc/httpd/conf/httpd.conf

  Important parameters:
  - ServerName
  - ServerAdmin

- Other configuration files: /etc/httpd/conf.d/
  (eg. welcome.conf)

- /sbin/service httpd reload

- Files to serve go in /var/www/html (by default).

Testing:

- telnet your.ip.address 80

  GET / HTTP/1.0
  Host: your.host.name

- Look for your content preceded by HTTP headers.

Log files:

- /var/log/httpd/error_log (when things go wrong)
- /var/log/httpd/access_log

Userdir (http://host/~username) configuration:

- UserDir public_html

FTP
---

Package name: vsftpd
Service name: vsftpd

- Anonymous FTP: files go in /var/ftp/pub

- Adding/removing local FTP users (eg. for public_html access):

useradd username
passwd username
userdel -r username

To restrict shell access, use 'useradd -s /sbin/nologin username'
(but add /sbin/nologin to /etc/shells)

Testing:

ftp your.ip.address
username
password
mkdir public_html
put - index.html
blah
^D

- Main configuration file: /etc/vsftpd/vsftpd.conf

  Important parameters:
  - anonymous_enable=NO
  - chroot_local_user=YES

- /sbin/service vsftpd reload

Testing:

telnet your.ip.address 80
GET /~username/ HTTP/1.0
Host: your.host.name

Mail
----

Package name: sendmail
Service name: sendmail

Configuration files in /etc/mail:
- sendmail.mc
  - m4 < sendmail.mc > sendmail.cf  (or just 'make'), then reload sendmail
- local-host-names (then reload sendmail)
- access (then 'make')

Remove accept_unresolvable_domains
Remove DAEMON_OPTIONS(`Port=smtp,Addr=127.0.0.1, Name=MTA')

Testing:

telnet your.ip.address 25
HELO bob
MAIL FROM: <...@...>
RCPT TO: <...@...>
DATA
Subject: test

test
.

Log file for sendmail: /var/log/maillog

POP
---

User configuration as for FTP.

Package name: imap
Service name: ipop3

Testing:

telnet your.ip.address 110
USER username
PASS password
LIST
RETR 1
DELE 1
QUIT