CWNA (Wireless Network) Part2

WLAN Applications

Access Role: Wireless LANs are deployed in an access layer role, meaning that they are used as an entry point into a wired network. In the past, access has been defined as dial-up, ADSL, cable, cellular, Ethernet, Token Ring, Frame Relay, ATM, etc. Wireless is simply another method for users to access the network. Wireless LANs are Data-Link layer networks like all of the access methods.

Network Extension: Wireless networks can serve as an extension to a wired network. There may be cases where extending the network would require installing additional cabling that is cost prohibitive. You may discover that hiring cable installers and electricians to build out a new section of office space for the network is going to cost tens of thousands of dollars. In  the case of a large warehouse, the distances may be too great to use Category 5. Fiber might have to be installed, requiring an even greater investment of time and resources. Installing fiber might involve upgrades to existing edge switches.

Building-to-Building Connectivity (Point to Point):

In a campus environment or an environment with as few as two adjacent buildings, there may be a need to have the network users in each of the different buildings have direct access to the same computer network. In the past, this type of access and connectivity would be accomplished by running cables underground from one building to another or by renting expensive leased-lines from a local telephone company. Using wireless LAN technology, equipment can be installed easily and quickly to allow two or more buildings to be part of the same network without the expense of leased lines or the need to dig up the ground between buildings. There are two different types of building-to-building connectivity. The first is called point-to-point (PTP), and the second is called point-to-multipoint (PTMP). Point-to-point links are wireless connections between only two buildings.

Building-to-Building Connectivity (Point to Multipoint):

Last Mile Data Delivery: Wireless Internet Service Providers (WISPs) are now taking advantage of recent advancements in wireless technology to offer last mile data delivery service to their customers. "Last mile" refers to the communication infrastructure—wired or wireless that exists between the central office of the telecommunications company (telco) or cable company and the end user.

Service Sets

A service set is a term used to describe the basic components of a fully operational wireless LAN. There are three ways to configure a wireless LAN, and each way requires a different set of hardware. The three ways to configure a wireless LAN are:

• Independent Basic Service Set (IBSS)
• Basic Service Set (BSS)
• Extended Service Set (ESS)

Independent Basic Service Set (IBSS):

An independent basic service set is also known as an ad hoc network. An IBSS has no access point or any other access to a distribution system, but covers one single cell and has one SSID. The clients in an IBSS alternate the responsibility of sending beacons since there is no access point to perform this task. In order to transmit data outside an IBSS, one of the clients in the IBSS must be acting as a gateway, or router, using a software solution for this purpose. In an IBSS, clients make direct connections to each other when transmitting data, and for this reason, an IBSS is often referred to as a peer-to-peer network.

Basic Service Set (BSS):

When one access point is connected to a wired network and a set of wireless stations, the network configuration is referred to as a basic service set (BSS). A basic service set consists of only one access point and one or more wireless clients.

A basic service set uses infrastructure mode - a mode that requires use of an access point and in which all of the wireless traffic traverses the access point. No direct client-to-client transmissions are allowed.

Each wireless client must use the access point to communicate with any other wireless client or any wired host on the network. The BSS covers a single cell, or RF area, around the access.

Extended Service Set (ESS):

An extended service set is defined as two or more basic service sets connected by a common distribution system. The distribution system can be either wired, wireless, LAN, WAN, or any other method of network connectivity. An ESS must have at least 2 access points operating in infrastructure mode. Similar to a BSS, all packets in an ESS must go through one of the access points.

Roaming: Roaming is the process or ability of a wireless client to move seamlessly from one cell (or BSS) to another without losing network connectivity. Access points hand the client off from one to another in a way that is invisible to the client, ensuring unbroken connectivity. When any area in the building is within reception range of more than one access point, the cells’ coverage overlaps. Overlapping coverage areas are an important attribute of the wireless LAN setup, because it enables seamless roaming between overlapping cells. Roaming allows mobile users with portable stations to move freely between  overlapping cells, constantly maintaining their network connection. Note: when roaming, we perform 15% to 20% overlapping.

Overlapping: On co-location overlapping occure, to avoid ovelapping we must change the channels.

IBSS

Lab1_Software based Bridge:

Step1: On PC1 > network and sharing center > manage wireless network > click on Add button (to create folder for WLAN profile for Ad-hoc mode) > click on Ad-hoc network > next > network name (SSID): Ad-hoc-test, security type: wep, security key: 123abc > next > next > close.

Step2: On PC2, PC3, and PC4 > Right click on network icon on task bar > now connect to Ad-hoc-test > give password > ok.

Step3: On PC1 > open network and sharing center > change adapter settings > merge both Local area connection and wireless network connection > select both > right click > Bridge connections > ok > right click on wireless network connection > properties > give IP, Gateway and DNS if not get > ok.

Now we created software based Bridge from PC1, and when PC2, PC3, PC4 wants to access Internet it will success.

Lab2_Internet connection sharing (in Ad-hoc mode):

Small office and home office, we can use ICS in ad-hoc mode. In windows ICS is the process of sharing a single Internet connection (DSL) between multiple users. A number of technologies use involved in ICS. For example: NAT, Baby DHCP, Basic Firewall, Cash DNS, Proxy server.

On wired network:

Step1: Install two link cards on ICS Server, and configure the link card which is connected to DSL.

Step2: Right click on the NIC which is connected to DSL > properties > sharing > check Allow other network users to connect through this computer Internet connection > ok > setting > Allow FTP, Telnet, etc.

Note: when we share Internet connection through ICS, the IP address format will be 192.168.137.any.

ICS on wired network:

ICS on wireless network:

Or:

BSS

Lab3_Creating a simple wireless network (single AP):

Step1: Connect to AP using web interface (every AP have builtin web server for configuration) > Internet explorer > http://192.168.1.1 > enter > username: admin, password: admin > enter.

Step2: Network > change IP address here (give any IP) > Wireless settings > basic settin > SSID: test, Region: Afghanistan, Channel: 11, Mode: 54Mbps (802.11g) > save.

Note: if we have same vendor equipements select propritary speeds mode.

ESS

Lab4_Creating two AP with roaming:

Step1: Connect to AP1 through web browser > http://192.168.1.1 > enter > username: admin, password: admin > ok.

Step2: Network tab > change IP address > save > Wireless tab > Basic settings > SSID: ccna, Region: Afghanistan, channel: 6, Mode: 54Mbps (802.11g) > save.

Step3: Connect to AP2 through web browser > http://192.168.1.1 > enter > username: admin, password: admin > ok.

Step4: Wireless tab > Basic settings > SSID: ccna, Region: Afghanistan, Channel: 1, Mode: 54Mbps (802.11g) > save. Now connect PCs to AP.

Note: on roaming cause we must overlapping 20%, and SSID and password of both AP wil be same and channels will be different.

Channels 1,3,6,7,11 are none overlapping channels. 1,6,11 channels are free channels.

Lab5_Configuring AP as DHCP Server:

Step1: Connect to AP > DHCP > Enable, give start IP, end IP, and reserved > save > manual reboot > System tools > Reboot > ok.

Note: In LAN we give IP time 7 days (optional), but in wireless network we mention as 8 hours (optional).

Lab6_Wireless station isolation:

We enable wireless station isolation/AP isolation, where students and visitors are resides.

AP isolation restricts WLAN station from accessing each other through WLAN.

Step1: Connect to AP > Wireless settings tab > check Enable AP isolation > save > ok.

Now ping between clients it will not access each other.

Lab7_Mac Filtering:

Using Mac filtering, we can  restrict unauthorized users/machines form connecting to the WLAN. AP operates at the data link layer and physical layer, so it can filter based on physical/Mac address.

Step1: Connect to AP > Wireless tab > wireless mac filtering > select Deny the stations not spesified by any enabled entries in the list to access > click on Enable > Ad new > give here Mac address of PCs that you want to allow > save > ok.

Lab8_Wireless Bridge mode (Point to Point):

Step1: Connect to AP1 using web browser > wireless tab > wireless mode > select Bridge (Point to Point), Now click on survey button to scan all Access points Mac address, on survey page select AP2 Mac address and connect or give manually AP2 Mac address > save.

Step2: Connect to AP2 using web browser > Wireless tab > wireless mode > select Bridge (Point to Point), Now give Mac of AP1 > save.

Note: In this case SSID and channel will be same. If we want to connect users then we select Bridge+AP mode.

Lab9_Wireless Bridge mode (Point to Multipoint):

Step1: Configure Point to Multipoint Bridge > connect to AP1 (Point to Multipoint Bridge) > wireless > wireless mode > Bridge (Point to Multipoint), here mention other two AP’s  Mac addresses > next > save > ok.

Step2: Connect to AP2 (Point to Point Bridge) > wireless > wireless mode > select Bridge (Point to Point), here give AP1 Mac address > save > ok.

Step3: Connect to AP3 (Point to Point Bridge) > wireless > wireless mode > select Bridge (Point to Point), here give AP1 Mac address > save > ok.

Lab10_Repeater Mode:

Repeater receives a wireless signal, regenrates the signal and then send it forward destination network.

Step1: Configure AP1 in Root mode > connect to the AP1 > wireless > wireless mode > select Access Point, Enable SSID broadcast > save > ok.

Step2: configure AP2 as Repeater > Connect to AP2 > wireless > wireless mode > select Repeater, give Mac address of AP1 > save > ok.

Wireles network:

Lab11_External Access Point (CPE):

CPE is use for external WLAN installation. Ex: In campus network.

Step1: Connect to E.AP (default IP 192.168.1.254, username: admin, password: admin) > network > give IP, subnet mask, gateway > save. > wireless tab > Basic setting > SSID: IT-Switcher, Region: pakistan, channel: 6, power: 27DBm Max (600m), or 24, 21, 18, 15 it is Radiation power > Mode: 54Mbps (802.11g) > save.

Wireless tab > wireless mode > Access point > save.

Lab12_E.AP Repeater mode:

Step1: Connect to E.AP > wireless > wireless mode > Repeater, give Mac address of AP > save.

Step2: Connect to AP > wireless > wireless mode > Access Point, Mac of E.AP(repeater) > save.

Lab13_E.AP+DHCP Server:

Step1: Connect to AP > advance setting > DHCP > Enable, static, end IP, address lease time, gateway, DNS > save > reboot (to reboot go to tools > reboot > reboot > ok.

Wireless CPE modes

AP Client router, AP router, AP.

Lab14_Configuring external CPE as a WISP client router:

Step1: Connect to the External CPE through web browser > username and password > Quick setup > next > select AP client router > next > select PPPoE > next > give username and password which are given by WISP > next > finish. OR,

Quick setup > next > select AP client router > next > Dynamic > next > SSID: Linkwisp (which are provided by wisp) > next > finish. Now we assign dynamically IP, Username, and Password. OR,

Quick setup > next > select AP client router > next > Static > next > give IP, SSID, Username, and Password which are given by WISP > next > finish.

Lab15_Configuring External CPE as AP Router:

Step1: Connect to E.AP through web browser > Quick setup > next > select AP Router > next > select PPPoE > next > give username and password (which are given by WISP) > next > SSID, Region , Channel, Mode, (For LAN) > next > finish.

Wireless Gateway (DSL):

A Gateway for router is a network device which allows communication of packets between networks. This is a difference between a gateway of router.

Gateway operates at all layer of OSI models, Router operates on Physical, Datalink, and Network layers.

Lab16_Configuring wireless gateway for Internet access:

Step1: Configure Internet settings (Ips settings).

Step2: Configure LAN IP settings.

Step3: Configuring DHCP for LAN clients.

Step4: Configuring SSID (WLAN) for WLAN settings.

Step1: Configure Internet settings (IP settings) > Connect to e1000 gateway through web browser > http://192.168.1.1 > enter > username and password > Setup > Basic setup > select Static IP, Internet IP, Gateway (DSL) > next > Network setup (LAN) > IP address: 172.16.10.1 > save > ok. Note: In LAN now we give static IP to PCs.

Step2: Configure DHCP > DHCP server > Enable > give start and end IP, client lease time (120) minuts > save.

Step3: Configure WLAN for WLAN stations > Wireless tab > Configuration view, Manual > network mode: Mixed, Network name (SSID): free-wlan, channel: 11, SSID: Enabled > save > ok.

Lab17_Mac filtering (Gateway):

Step1: Connect to Gateway > Wireless tab > Wireless Mac filter > Enable > select Permit PCs listed below to access the wireless network, (here we give Mac addresses of PCs and these will be allowed other all will be denied) > save.

Lab18_Access Restrictions (only in gateway and CISCO wireless routers):

Internet Access restriction: is a limited level Firewall, allows to create Internet access policies. Each policy can have a no of conditions:

• The list of computers to which the policy applies
• The schedule during which the policy is applicable (day+time restrictions)
• URLs either allowed or denied (www.facebook.com)
• Website either allowed or blocked based on regulas expression or keyword
• Blocked Applications
• Port or port range

Define Internet access policies, we have three policies: 1. No Internet/network access, 2. Internet access, 3. Internet access for specific group.

Step1: Connect to gateway > Access Restrictions > Internet access policy > Access policy: 1, Access restriction: Deny schedule: Everyday, applied PCs: edit, here we give range of PCs to implement this policy, > save > ok.

Step2: Connect to Gateway > Access Restrictions > Internet access for all in break time: access policy: 2, > access restrictions > access restriction : Allow, schedule: Everyday, Time: 12PM to 02PM, website blocking by keyword: Keyword1: Tube, Keyword2: adult > URL1: www.facebook.com, blocked applications: select here applications that you want to block: Telnet, Ping, FTP, etc > Apply PCs: Edit list, give here IP range which you want to apply this policy > save > ok.

Step3: For managers Internet access: access policy: 3, Access restriction > Access Restriction: Allow: Everyday, Time: 8AM to 4PM, Enter policy name: Managers > Eanabled, > save > ok.

Wireless Network Security

Two types of Access Point:

1. Simple Access point: in simple Access point we can’t block any URL or Key words
2. Router Access point: in router Access point we can block any URL and key words

Wireless Print Server

Lab19_Configuring wireless Print Server (Ad-hoc mode):

Step1: Connect to the wireless Print server through wireless (in Ad-hoc) > click on wireless icon adn select WLAN-PS > connect > ok.

Step2: Open network and sharing center > click on wireless network connection > Properties > Ipv4 > properties: 192.168.0.20 > ok. Now Ping to 192.168.0.10.

Step3: Connect to the wireless Print server > Internet explorer > username, password > Setup: system (form here we change name and user name password) > save and restart.

Step4: Setup: wireless > network type (Ad-hoc), SSID: WLAN, Channel: 11, Transmission rate: Auto, wireless mode: B/G mixed > advanced settings: securityu tupe > Wep > key index: 1, Encryption type: 64bit, key: 123, Authentication: shared > save.

Installing Print Server: Insert Print server software CD to CDROM > run > click on wireless Print server > setup wizard > next > select wireless print server > next > Yes... > password of Print server > next > Communication type: Ad-hoc > next > give security > next > give IP > next > next > add new printer ( Printer drive) > add a local printer > select Printer > next > next > finish.

Note: now we send jobs to Print server on which Printer driver and software of Print server installed. If we want to send jobs from other clients direct, then we must install Printer driver and Print server software.

Note2: if we want to install Printer in infrastructure mode, then we must connect Print server with access Pointy.

Lab20_Configuring wireless Print server in infrastructure mode:

Step1: Install Printer driver on the Print server.

Step2: Configure the wireless Print server > connect to WLAN Print server using web browser > http://192.168.0.10 > user: admin, password: 123@qwe > setup, wireless > network type: Infrastructure, Channel: 1, SSID: CCNA, > save. (channel and SSID of AP).

Step3: Print server > run the software CD > select wireless Printer > next > ........ > finish.

End...