RH033 Unit14 Network Clients

Objectives Upon completion of this unit, you should be able to: Browse the web
Exchange emails and instant messages
Access a Linux system remotely
Transfer files between systems
Use network diagnositc tools
Web Clients 1) Firefox 2) Other web browsers 3) Non-GUI web browsers 4) wget Firefox 1) Fast, lightweight, feature-rich web browser Tabbed browsing
Popup blocking
Cookie management
Multi-engine search bar
Support for many popular plug-ins
Themes and Extensions
Non-GUI Web Browsers 1) links Provided by the elinks rpm
Full support for frames and ssl
Examples
links http://www.redhat.com
links –dump http://www.redhat.com
links –source http://www.redhat.com
wget 1) Retrieve files via HTTP and FTP 2) Non-interactive – useful in shell scripts 3) Can follow links and traverse directory trees on the remote server – useful fo mirroring web and FTP sites Email and Messaging 1) Evoluation 2) Other email clients 3) Non-GUI email clients 4) Gaim Evolution 1) Default email and groupware tool 2) Provides email, calendar, tasks and contacts 3) Can maintain multiple accounts at once 4) Supports GnuPG (GNU Privacy Guard) encryption and signatures 5) “Trainable” bayesian spam filters 6) Task/ Calendar notifications in Gnome clock 7) Can sync with many PDAs Configuring Evolution 1) Defining accounts Tools –> Settings –> Mail Accounts
Supports IMAP, pop, Novell Groupware, Usenet and local email accounts
MS Exchange support via plug-in
Provided by evolution-connector rpm
Install before configuring other accounts
Other GUI Mail Clients 1) Thunderbird (Standard Mozilla email client) 2) Kmail (KDE email client) Non-GUI Mail Clients 1) mutt Support pop, imap and local mailboxes
Highly configurable
Mappable hotkeys
Message threading and colorizing
GnuPG integration
Context-sensitive help with ‘?’
Gaim 1) Multi-protocol Instant messaging client 2) Available in Red Hat Enterprise Linux Client 3) Supports AIM, MSN, ICQ, Yahoo, Jabber, Gadu-Gadu, SILC, GroupWise Messenger, IRC and Zephyr networks 4) Plugins can be used to add functionality. OpenSSH: Secure Remote Shell 1) Secure replacement for older remote-access tools 2) Allows authenticated, encrypted access to remote systems ssh [user@]hostname
ssh [user@]hostname command
SCP: Secure File Transfer 1) Secure replacement for rcp 2) Layered on top of ssh scp source destination
Remote files can be specified using: [user@]host:/path/to/file
3) Use –r to enable recursion 4) Use –p to preserve times and permissions 5) Use –C to compress datastream rsync: Efficient File Sync 1) Efficiently copies files to or from remote systems 2) Uses secure ssh connections for transport rsync: *.conf barney:/home/joe/configs
3) Faster then SCP – copies differences in like files OpenSSH Key-based Authentication 1) Optional, password-less, but still secure, authentication 2) Uses two keys generated by ssh-keygen: private keys stays on your system. Usually passphrase-protected (recommended)
3) public key is copied to destination with ssh-copy-id ssh-copy-id [user@]host
OpenSSH Key-based Authentication continued 1) An authentication agent stores decrypted private keys Thus, passphrase only needs to be entered once
An agent is provided automatically in GNOME
Otherwise, run ssh-agent bash
2) Keys are added to the agent with ssh-add FTP Clients 1) CLI: lftp 2) GUI: gFTP Application –> Internet –> gFTP
Allows Drag and Drop transfers
Anonymous or authenticated access
Optional secure transfer via ssh (sftp)
smbclient 1) FTP-like client to access SMB/CIFS resources 2) Examples: smbclient –L server1 (lists shares on server1)
smbclient –U student //server1/homes (access a share)
File Transfer with Nautilus 1) File/ Connect to Server 2) Graphically browse with multiple protocols 3) Allow drag and drop file transfers 4) Supported connection types: FTP, SFTP, SMB, WebDAV, Secure WebDAV 5) Can also connect via url Xorg Clients 1) All graphical applications are X clients Can connect to remote X servers via tcp/ip
Data is not encrypted but can be tunneled securely over an ssh connection (ssh –X user@hostB xterm&)
2) xterm will display on hostA’s X server 3) Transmitted data will be encrypted through the ssh connection Network Diagnostic Tools 1) ping 2) traceroute 3) host 4) dig 5) netstat 6) gnome-netool (GUI) End of Unit14 1) Quesitons and Answers 2) Summary Firefox, Evolution and Mutt
Basic network diagnostic tools
The importance of secure network clients