TUTORIAL: Linux Networking Troubleshooting
A linux-based introduction to TCP/IP networks.
The emphasis is practical rather than theoretical, covering
situations you're likely to encounter.
We use everyday tools
to show you what's happening on your network. This helps you
understand the TCP/IP at a deeper level and is also great for
TCP/IP is very simple, and consists of many, easily-understood
building blocks. These can be put together to build extremely
complex networks (in the same way that individual chess moves
are very simple, but chess matches can be complex.)
What you will learn
- how to configure machines to operate correctly on your
LAN and across the Internet
- how to troubleshoot just about any networking problem
Who should attend
- technical staff, technical managers, or technical sales
- consultancy and services staff installing or managing
- people using TCP/IP networks every day ...
- who are managing and building networks, or ...
- who are responsible for an organization's applications and
systems as a whole
- people building TCP/IP networks at home
- anyone connecting to the Internet
- students at any level studying computer networks
- TCP/IP is a packet-switching network
- How that helps us -- we can use a "packet sniffer"
to see what's happening. (The network admin's
equivalent of the electrical engineer's
- Tools (free, open-source)
- The tcpdump packet sniffer
- The ethereal protocol analyzer
- Installing and using the tools
- TCP/IP networking is in layers
- The IP layer
- hardware independent (important to allow LANs to
grow into what became the Ethernet -- same
networking system for LAN and WAN)
- IP addresses and what they mean
- Ethernet -- the most usual hardware layer
- how Ethernet addressing works
- ARP (address resolution protocol) links the Ethernet
hardware to the high-level IP layer
- watching ARP with a sniffer
- common problems
- What a netmask is
- a netmask + an IP address specifies a range of IP
- most common use is to say "this range of IP
addresses is connected to my local wire"
- any addresses not in that range can only be reached
by a ...
- Routers, and routing
- how IP routing works (conceptually very simple, but
- the idea of the default gateway
- routing tables
- troubleshooting routing problems
- using more than one router: the 'route' command
- The DNS - domain name system
- what the DNS is all about -- convert a host name to
a numeric IP address
- how information is stored in the DNS -- A, PTR, MX,
CNAME, TXT and SOA records
- configuring a machine to use the DNS
- common DNS problems
- what "reverse lookups" are (convert a numeric IP
address to a name)
- Higher level protocols
- TCP makes it easy to have networked applications
- what TCP gives us -- reliable data transfer even
when there are problems on the network.
- How e-mail uses TCP -- SMTP and POP.
- Troubleshooting e-mail
- The UDP and ICMP protocols