CCNA Wireless Chapter 12, 13 and 14 Exam Answers

Mobility is not synonymous with hot spot connectivity , rather it means a client can move between APs while keeping its IP address

The two types of client mobility are…
1) L2 mobility – client roams AP’s in same subnet
2) L3 mobility – client roams to AP in different subnet

What is a mobility group?
A group of WLC’s which share information with eachother

What is the maximum amount of WLC’s allowed in a mobility group?

What are the four requirements when creating mobility groups?
1) IP connectivity between WLC’s
2) Same workgroup name
3) Same virtual interface IP (ex. in labs)
4) The MAC and IP of every other device in the group

What is a mobility domain?
The scope of communication between WLC’s in a WLAN

Mobility groups can be used to isolate roaming between different VLAN’s

Can clients roam between mobility domains?

What 4 things are required when a client is roaming between controllers?
1) Same mobility domain
2) Same revision of code
3) All AP’s need to have same SSID’s available
4) Again, virtual interface IP has to be the same

What is a simple way to describe intra-controller roaming?
New AP, same WLC

In intra-controller roaming, when is the client entry made in the database?
After the first AP association

What exactly is PKC?
Proactive key caching, it creates faster roaming times for 802.11i clients

What is a simple way to describe inter-controller roaming?
A client roams between two different WLC’s

What is the basic 4 step process of a client performing inter-controller roaming?
1) The client roams from WLC1 to WLC2
2) WLC2 makes a mobility announcement in order to find the WLC that has the client’s MAC (which is WLC1)
3) WLC1 responds to this announcement, handshakes and ack’s
4) This process moves the client DB entry to WLC2

How is L3 roaming accomplished?
Through a process called EoIP (ethernet over IP).
It is a tunnel created between controllers.
Original controller called “anchor”, the new controller is called the “foreign”

What are the two types of L3 roaming?
1) Symmetric
2) Asymmetric

The 3 primary components of WLC configuration are:
1) WLAN – the SSID and its corresponding parameters
2) Interface – virt. conn. to IP stack
3) Port – phys. connection to wired LAN

Two types of interface on a WLC are:
1) Static
2) Dynamic

Out of the two types of interfaces on a WLC, which one is created by the WLC and which one is created by an administrator?
Static: WLC
Dynamic: Administrator

Describe the management interface:
For in-band management
Used to communicate with other NW devs.
Also used by LAP in discovery phase

Describe the AP manager interface:
This is how the WLC communicates with LAP’s

Describe the virtual interface:
Used by WLC to terminate VPN’s from LAP’s, for DHCP relay connections, mobility management etc

What is special about the virtual interface?
It should not have a routable IP

Describe the service port:
For out-of-band management

What is special about the service port?
No trunking support

Describe the role of dynamic interfaces:
They link SSID’s to VLAN’s

What is the maximum amount of dynamic interfaces allowed on a WLC?

What 4 roles can an AP fulfill?
1) AP
2) Repeater
3) WG bridge
4) Scanner

3 things required for converting an autonomous AP to an LWAPP LAP are:
1) Upgrade tool
2) IPSU tool
3) LAP IOS image

What version does the LAP IOS image have to be?
12.3 (7) JA or above

What does the text file contain which is used to upgrade the IOS for LAP purposes?
1) IP of AP
2) Username/PW for telnet auth
3) Enable mode PW

What IP is used for TFTP servers pushing out autonomous AP IOS images?
It must be on the /24 NW