Data Networking/Fall 2014/DPDZ
Group members
[edit | edit source]Darshan Patel
Parismita Nath
Jieling Ding
Chengjie Zhu
Behavior of the Protocol
[edit | edit source]DHCP
[edit | edit source]Within a local network, DHCP assigns a local IP address to devices connected to the local network.The DHCP server manages a pool of IP addresses and information about client configuration parameters such as IP address, default gateway, domain name, the name servers, and timeservers.
• DHCP can simplify the job that assigns IPs to clients every time they enter. If same host returns to the network within the lease time it will be provided the same IP address.
• DHCP utilizes MAC address for assigning IPv4 addresses and can avoid conflicting in assigning IPs.
DNS (Domain Name Server)
[edit | edit source]1. The main function of Domain name server is to translate domain name into IP addresses.
2. DNS is based on a hierarchical and logical tree structure called the domain name space. Different organization can create their own private IP address, using their own domain namespaces.
The name space has a maximum depth of 127 levels.Domain names are limited to 255 characters in length
3. A zone is a portion of the DNS namespace generally stored in a file, and can contain multiple domains. Using the zone, the DNS server response to all the queries about hosts in its zone.
4.There are two types of servers, Authoritative – maintains the data
Master- where the data is edited
Slave – where data is replicated to
Caching – stores data obtained from an authoritative server
PXE boot
[edit | edit source]The PreReboot execution Environment (PXE) describes a standardized client-server environment that boots a software assembly, retrieved from a network, on PXE-enabled clients. After parsing a PXE enabled DHCP server DHCPOFFER, the client will be able to set its own network IP address, IP Mask, and to point to the network located booting resources, based on the received TFTP Server IP address and the name of the Network Bootstrap Program. The Client next transfers the NBP into its own random-access memory (RAM) using TFTP, possibly verifies it and finally boots from it. NBPs are just the first link in the boot chain process and they generally request via TFTP a small set of complementary files in order to get running a minimalistic OS executive (Linux kernel+initrd). When the small OS executive is alive it loads its own fully capable network drivers, a full TCP/IP stack, and the rest of transfers for booting or installing a full OS are performed not by TFTP but at this point using more robust transfer protocols like HTTP, CIFS, NFS, etc. Web server: Web Servers are used to serve Web Pages requested by client computers. Apache is the most commonly used Web Server on Linux systems.
Hierarchy
[edit | edit source]
Command used
[edit | edit source]DNS CONFIGURATION:
[edit | edit source]Step 1: Install Ubuntu package bind9
Sudo apt-get install bind9
Step 2: Configure the interfaces auto eth0
iface eth0 inet static
address 192.166.1.2 netmask 255.255.255.0 network 192.166.1.0 broadcast 192.166.1.255 gateway 192.166.1.1
Step 3: Restart networking daemons
sudo /etc/init.d/networking restart
Step 4: Create a Server name
sudo nano /etc/hostname Ubuntu
Step 5: Once the bind9 is installed edit the following
Named.conf.options
sudo nano /etc/bind/named.conf.options
forwarders
{192.166.1.1;
8.8.8.8;
8.8.4.4;};
Named.conf.local
sudo nano /etc/bind/named.conf.local
FORWARD ZONE
zone "dpdz.com"
{type master;file "/etc/bind/zones/db.dpdz.com";};
REVERSE ZONE
Server IP 192.166.1.5
zone "1.166.192.in-addr.arpa" {type master;file "/etc/bind/zones/db.192"; };
Step 6: Create the directory zones in /etc/bind/
sudo mkdir /etc/bind/zones
Step 7: create two files in zone directory sudo cp /etc/bind/db.local /etc/bind/zones/db.autun.hom Edit the file sudo nano /etc/bind/zones/db.dpdz.com; BIND data file for local loopback interface;
$TTL 604800
@ IN SOA Ubuntu.dpdz.com. webuser.dpdz.com. (
2 ; Serial
604800 ; Refresh
86400 ; Retry
2419200 ; Expire
604800 ) ; Negative Cache TTL
;
dpdz.com. IN NS Ubuntu.dpdz.com.
Dpdz.com. IN A 192.166.1.2
;@ IN A 127.0.0.1
;@ IN AAAA ::1
Ubuntu IN A 192.166.1.2
gateway IN A 192.166.1.1
win7pc IN A 192.166.1.50
www IN CNAME dpdz.com
Step 8: create reverse lookup zone file
sudo cp /etc/bind/db.127 /etc/bind/zones/db.192 Edit the file sudo nano /etc/bind/zones/db.192
; ; BIND reverse data file for local loopback interface ;
TTL 604800
@ IN SOA Ubuntu.dpdz.com. webuser.dpdz.com. (
2 ; Serial
604800 ; Refresh
86400 ; Retry
2419200 ; Expire
604800 ) ; Negative Cache TTL
;
IN NS Ubuntu.
1 IN PTR gateway.dpdz.com.
5 IN PTR Ubuntu.dpdz.com.
50 IN PTR win7pc.dpdz.com.
Step 9: check whether the zone files are working properly or not. Forward zone named-checkzone dpdz.com /etc/bind/zones/db.dpdz.com reverse zone named-checkzone dpdz.com /etc/bind/zones/db.192.
Step 10: Edit named.conf.resolv.conf sudo nano /etc/resolv.conf
Nameserver 192.166.1.5 domain dpdz.com search dpdz.com
Step 11: Restart the bind sudo /etc/init.d/bind9 restart
Step 12: check setting in log file tail -f /var/log/syslog there should not be any error. Step 13: Nslookup dpdz.com Nslookup 192.166.1.2
Install and set up the DHCP server
[edit | edit source]Step 1. Making changes in the /etc/network/interfaces file
sudo nano /etc/network/interfaces
auto eth0
iface eth0 inet static
address 192.166.1.5
netmask 255.255.255.0
gateway 192.166.1.1
Then restart it
sudo /etc/init.d/networking restart
Step 2. Set DNS sudo nano /etc/resolv.conf nameserver 192.166.1.1
Step 3. Install DHCP server on Ubuntu 14.04 LTS
sudo apt-get install isc-dhcp-server –y
Step 4. Edit file /etc/default/isc-dhcp-server to set the interface eth0
sudo nano /etc/default/isc-dhcp-server INTERFACES="eth0"
Step 5. Edit the file /etc/dhcp/dhcpd.conf
sudo nano /etc/dhcp/dhcpd.conf
Set the domain name and domain-name servers:
option domain-name "dpdz.com";
option domain-name-servers 192.166.1.2;
Step 6. Define the subnet, range of IP addresses
A slightly different configuration for an internal subnet.
subnet 192.166.1.0 netmask 255.255.255.0 {
range 192.166.1.10 192.166.1.210;
option domain-name-servers 192.166.1.2;
option domain-name " dpdz.com ";
option broadcast-address 192.166.1.255;
default-lease-time 60000;
max-lease-time 72000;
}
PXE boot CONFIGURATION
[edit | edit source]Step 1. Set up your Server sudo apt-get install dhcp3-server tftpd-hpa syslinux nfs-kernel-server initramfs-tools
Step 2. Configure DHCP server allow booting; allow bootp; filename "/pxelinux.0"; host pxe_client { hardware ethernet;fixed-address 192.168.1.5;}
Step 3. Restart DHCP sudo service isc-dhcp-server restart
Step 4. Configure the TFTP Server Configure tftp root directory sudo mkdir -p /tftpboot/pxelinux.cfg Copy across bootfile sudo cp /usr/lib/syslinux/pxelinux.0 /tftpboot Create default configuration file /tftpboot/pxelinux.cfg/default
Step 5. Set permissions sudo chmod -R 777 /tftpboot Start the tftp-hpa service: sudo /etc/init.d/tftpd-hpa start Configure OS root Create a directory to hold the OS files for the client sudo mkdir /nfsroot configure your /etc/exports to export your /nfsroot /nfsroot 192.168.1.2 (rw,no_root_squash,async,insecure)
Step 6. sync your exports sudo exportfs –rv
Web Server CONFIGURATION
[edit | edit source]Step 1. config webserver：
get installed apache2
sudo apt-get install apache2
sudo mkdir -p /var/www/dpdz.com/public_html
sudo chown -R $USER:$USER /var/www/dpdz.com/public_html
sudo chmod -R 755 /var/www
sudo nano /var/www/dpdz.com/public_html/index.html
<html>
<head> <title>www.dpdz.com</title> </head> <body> dpdz group members: Darshan Patel, Parismita Nath, Jieling Ding, Chengjie Zhu </body>
</html> sudo cp /etc/apache2/sites-available/000-default.conf /etc/apache2/sites-available/dpdz.com sudo nano /etc/apache2/sites-available/dpdz.com <VirtualHost *:80>
ServerAdmin webmaster@dpdz.com
ServerName dpdz.com
DocumentRoot /var/www/dpdz.com/public_html sudo a2dissite *default sudo a2ensite dpdz.com sudo service apache2 restart
Step 2. config firewall:
only allow the our own network 192.166.1.0/24 to connect to webpage
sudo nano /etc/iptables.firewall.rules
File: /etc/iptables.firewall.rules
1 *filter
2
3 -I INPUT -p tcp --dport 80 -j DROP
4 -I INPUT -s 192.166.1.0/24 -p tcp --dport 80 -j ACCEPT
5
6 COMMIT
sudo iptables-restore < /etc/iptables.firewall.rules
sudo iptables –L
Chain INPUT (policy ACCEPT)
target prot opt source destination
ACCEPT tcp -- 192.166.1.0/24 anywhere tcp dpt:http
DROP tcp -- anywhere anywhere tcp dpt:http
Chain FORWARD (policy ACCEPT) target prot opt source destination
Chain OUTPUT (policy ACCEPT) target prot opt source destination
Testing
[edit | edit source]DHCP
[edit | edit source]-sudo ifconfig
DNS
[edit | edit source]sudo ifconfig
- nslookup domain name and IP Address
ifconfig
WEB SERVER
[edit | edit source]ping DHCP server
Use IP address to surf the WEB
Use domain name to surf the Web
Add-on items & Future improvements
[edit | edit source]NFS
[edit | edit source](Network File System) allows you to 'share' a directory located on one networked computer with other computers/devices on that network. The computer where directory located is called the server and computers or devices connecting to that server are called clients. Clients usually 'mount' the shared directory to make it a part of their own directory structure.
VPN
[edit | edit source]Virtual Private Network lets you establish a secure connection over the non-secure Internet, e.g. from a notebook to an office server. Getting a VPN to work requires general knowledge on networks, and it may require some specific knowledge on routers, firewalls and VPN protocols.
NIS
[edit | edit source]Network Information Service, or (originally called Yellow Pages or YP) is a client–server directory service protocol for distributing system configuration data such as user and host names between computers on a computer network.
Backup
[edit | edit source]Backup refers to the copying and archiving of computer data so it may be used to restore the original after a data loss event. The primary purpose is to recover data after its loss, be it by data deletion or corruption.