Aim of the seminar Network Tools - MENDELU

• Finding out or set your own IP address.

• Finding out the MAC address your own and MAC of your neighbors.

• Finding out your DNS server.

• Determination the IP address by domain name.

• Verifying availability to the other side and displaying transmission speed for the simple „request–reply“ communication.

• Finding out the entire routing path to the other side.

• Searching for more detailed information for the given SLD (second level domain).

• To open remote session on the servers akela.mendelu.cz and user.mendelu.cz .

• To upload/download files to/from them.

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Aim of the seminar

Network Tools

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Network nodes addressing

– HW address (MAC address) is given to a network adapter when it is manufactured. It has 48 bites.

Example: 00-10-5A-44-12-B5 (in hexadecimal notation)

0000 0000 0001 0000 0101 1100 0100 0100 0001 0010 1101 0101 – 48 bites (6x8)

– Logical address (IP address) is configured manually by user (administrator) or automatically.

IPv4 address has 32 bites.

Example: 172.16.254.1

– Domain name is assigned within the DNS (Internet Domain name system). Example: akela.mendelu.cz

IRC - Lecture 2 - Networking

What we already know

IRC - Lecture 2 - Networking 3

Domain Name System (DNS) • The number of an IP address can be (and usually is) represented by

a name or series of names called domain name

• Domain name locates an organization or other entity on the Internet. For example, the domain name akela.mendelu.cz locates an Internet address for domain "mendelu.cz" and a particular host server named „akela" at Internet point (i.e. IP address) 195.178.72.100

• DNS namespace - All domain names binding to IP addresses create hierarchical administrative namespace supporting Internet Domain name system (DNS)

• A DNS server is a computer registered to join the Domain Name System. DNS server runs special-purpose networking software, features a public IP address, and contains a database of network names and addresses for other Internet hosts.

What we already know

IRC - Lecture 2 - Networking 4

DNS Namespace

What we already know

IRC - Lecture 2 - Networking 5

Principle of DNS • Domain names need to be converted to IP addresses as this is required by

lower layer protocols.

• The conversion of domain names to IP addresses is performed by implementing of DNS protocol.

• DNS protocol implementation

• Since an implementation of the DNS protocol is built into every network application program, the conversion is fully transparent to end users.

What we already know

Network Tools

What are Network Tools

?? Network tools/Network utilities are software

utilities designed to analyze and configure various aspects of computer networks.

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Network Tools • Network utilities are available on the different

network operating systems (for example on Linux, Microsoft Windows, OS X, …..)

• Network utilities set/display configuration of computer network interfaces, enable connection the remote computer, upload/download files.

• Network utilities check network connection, measure the network traffic performance, display network statistics, are useful for network troubleshooting.

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Network Tools The most common tools found on most operating systems include: 1. ifconfig/ipconfig allows for network interface configuration.

2. ping checks connectivity to other side (reports packet loss and response time).

3. arp allows to view and modify the ARP table including IP and MAC addresses of network neighbors.

4. route displays an IP routing table.

5. traceroute/tracert shows the series of successive nodes a packet goes through en route to its destination on a network.

6. nslookup gives a query a DNS (Domain Name System) server for obtaining DNS information.

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Network Tools Network

WAN

Classroom Classroom

University LAN

Switch Switch

Router Router

Border router

Google LAN

Border router

akela.mendelu.cz

www.google.com

Domain „mendelu.cz“

Domain „google.com“

Network Tools

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• Connection to GNU/Linux server akela.mendelu.cz

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Network Tools

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my_login xxxxxxx

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Network Tools TCP/IP interface configuration query - MAC (HW)

address and IP address

• Linux (akela.mendelu.cz) - /sbin/ifconfig

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IP address

MAC address

IP host reachability test – ping [hostname] Measuring the round-trip time for messages sent from the

originating host to a destination computer.

• Linux ping utility

Network Tools

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Round-trip time

MAC to IP address resolution - the „Net Neighbors“ MAC addresses finding

• Linux arp utility - display the content of ARP cache (ARP table)

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Network Tools

Neighbor name

Neighbor IP address

NetworkTools Display of Routing table

• Linux utility route

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NetworkTools

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• Linux utility netstat –r - displays network connections for the TCP Transmission Control Protocol (both incoming and outgoing)

Diagnostic tool for displaying the route (path) and measuring transit delays of packets across an IP network.

• Linux – traceroute [hostname]

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Network Tools

Network Tools

• Open Command Prompt window on the local PC (OS Microsoft Windows 10)

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Network Tools

• MS Windows – ipconfig/all

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Host name

IP address

Network Tools

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• Windows ping utility

Round-trip time

Network Tools • MS Windows – arp utility

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Neighbor IP address

Network Tools

• MS Windows – tracert [hostname]

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Network Tools • MS Windows – route print

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Network Tools

• MS Windows - netstat -r

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• Query Internet name servers interactively or non-interactively (DNS lookup utility)

– nslookup (Linux, MS Windows)

Network Tools

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NetworkTools • Secure transfer file from/to a remote host

(download/upload)

– Linux – scp [[user@]host1:]file1 [[user@]host2:]file2

– MS Windows – winscp program

• Logging to the remote host (open the remote session)

– Linux – ssh [user@]hostname [command]

– MS Windows – putty program

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• Online Ping • Traceroute • DNS lookup • WHOIS • Port check • Reverse lookup • Proxy checker • Bandwidth meter • Network calculator • Network mask calculator • Country by IP • Unit converter Tool for general purpose

Network tools online http://www.ping.eu

Basic Network tools

Additional Network tools

Network tools online www.whois.com

• Domain name lookup service to search the whois database for domain name registration information.

• WHOIS is a query and response protocol that is widely used for querying databases that store the registered users or assignees of an Internet resource, such as a domain name, an IP address block, or an autonomous system, but is also used for a wider range of other information.

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Network tools

Schema

Neighbors IP and MAC address ?

My

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https://www.youtube.com/watch?v=PBWhzz_Gn10

Warriors of the Net