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Network Management. Remote Network Management & Network Security. Learning Objectives. Upon successful completion of this lesson, you will be able to:. Identify the considerations for successful network management.
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Network Management Remote Network Management & Network Security
Learning Objectives Upon successful completion of this lesson, you will be able to: • Identify the considerations for successful network management. • State the purpose of offering subscription rates, and how it may improve network performance. • State the benefits of using SNMP to manage the network. • List the methods for accessing BreezeACCESS radios. • State the purpose and function off the BreezeCONFIG Utility. • Describe how to implement security within a network.
Network Considerations • Capacity and subscription rates • Wireless Network Security • Remote Management of Wireless Networks • Performance Metrics & System Reliability • Breakdowns and Response Plans
Subscription Rates • Utilize the network better - different subscription fees during different hours (e.g. residential will pay less during working hours, business will pay less during non-working hours) • Propose usage-based billing to customers
Data Model • Estimated Parameters • Households Passed/sq Mi – Typically Focused on the Suburban Range of 400 to 600 HH/sq Mi • Coverage – Typically 80% of Cell Has Useable Service • Penetration – Amount of Covered Users Who Accept the Service. Typically 10% to 25% • Online Ratio – Ratio of Active Users to Total Number of Subscribers. Typically 30% to 50% At Peak Busy Hour. • Active/Online Ratio – Ratio Of The Amount Of Time User Is Transmitting/Receiving vs Total Time Online. Typically 10% to 20%
Bandwidth Considerations • Bandwidth Management • The selling of bandwidth in standard increments, such as: • 128 kbps • 256 kbps • 512 kbps • 1.5 mbps • Rate structures • Cost of management • Rate vs. return
What is a Network Management System? • An automated monitor & control system. • Enables the user to “feel” the network and detect failures, bottlenecks and abnormal event in real time. • Sometimes automatically fixes minor problems
Why is Network Management Important? • Cost - Manual management is costly. • Customer Service - Maximizes service ability by allowing provider to know of problems before customer, and automated problem tracking. • Knowledge Factor - Provides for knowledgeable decisions in capacity and planning by providing precise numbers on utilization, errors, etc.
Automated Management Provides a Key Knowledge Factor • Enables “smarter” planning of network growth by knowing exactly what your network utilization is at every link. • Allows for maximizing utilization of current resources, by knowing the least utilized resources, you can balance your traffic load. • Allows for costing analysis, and business planning, by knowing your customer utilization trends and knowing exactly where are your “problem” areas in the network.
What is SNMP • Simple Network Management Protocol. • SNMP is an INTERNET protocol. • SNMP is a protocol that enables you to communicate between devices. • The protocol is used to manage and monitor devices on a network.
Benefits of SNMP • Enables you to CONFIGURE devices from a remote location. This allows you to make changes or, just view current settings of the device. • Enables you to MONITOR devices. Monitoring let you see the information as media utilization, amount of errors, and amount of re-transmissions. • SNMP TRAPS give you an alert message when status of your unit has changed. Example the unit has associated to another Access Point. • Helps you in troubleshooting and maintaining your network’s devices.
SNMP Version • SNMPv1- Existing standard, Security based on Community Strings that are passed in CLEAR TEXT. • SNMPv2- Gets information in Bulk additional security and commands, Security (encryption). • SNMPv3- Best Security, Security is done with Authentication and DES Encryption. • Versions 2 & 3 are not supported by Alvarion at this time.
Main SNMP Commands • GET - Used by the Network Management Station to retrieve a value from an agent. • SET - Used by the Network Management Station to change and apply values to an agent. • TRAP – Used by an AGENT to inform a Network Management Station of an event.
Community Strings • Read-Only Community String- Allow Users/Management station only to view information from a device • Read-Write Community String- Allows Users/Management stations to view and change setting on a device
Management Information Base (MIB) • A text file that can be viewed and edited with a viewer, such as Notepad. • It provides a directory like structure to all Management Information. • It defines and describes components of a product and Object Identifier
Types of MIB’s • Public MIB (standard) This is a MIB that has common variables for same type devices. For example, our devices are bridges and therefore, respond to standard bridge MIBs (RFC 1286) and MIB II (RFC1213). • Private MIB (Enterprises) A private MIB has additional variables specific to a vendors product. For example, our devices have additional features that normal bridges don’t have; i.e Multi-Rate, Load Sharing, and others. We have our own proprietary MIB to support these features.
Main Network Management Components • Agents – This is the component in a device that makes it SNMP capable • Management Platform – This is the software program that allows you to communicate with an Agent. • Management Station- This is the station which has the management platform software installed.
BreezeACCESS Administration • BreezeACCESS easy to use interface allows configuration, monitoring and management of BreezeACCESS units in the following methods: • Locally – using an ASCII terminal • Remotely – using Telnet • Remotely – SNMP • BreezeCONFIG • SNMP management software • Unit configuration upload/download is possible via TFTP. • Software upgrade is done via TFTP or FTP • Dual flash bank mechanism ensures a robust procedure.
Remote Management • BreezeCONFIG Features: • Windows based application. • Provides complete configuration & monitoring capabilities of all BreezeACCESS products. • Automatic discovery of BA devices in the local network. • Provides TFTP application for parallel upgrades. • Enables configuration of numerous units simultaneously.
Remote Management • BreezeCONFIG is not: • A full scale SNMP manager • No History, Trends, advanced paging functions • No support for other devices on network • There is a version for each style radio you are using • DS.11 • VL, etc.
SNMPc From Castle Rock Software • Network Management Application That Helps You Manage BreezeACCESS Units On your Network
Wireless Network Security • Security is one of the most important determinants of the success of a Wireless Network. • Wireless Network Security Elements: • Security is addressed at various levels in a Wireless Network to implement the above Security Elements.
Security Levels Radio Subscriber Network Protocol VPN Levels
Radio Level - GFSK • Subscriber Unit (SU) - Access Unit (AU) Association: • IEEE 802.11 Authentication • RC-4 Algorithm • 40-bit shared key • The shared key can be changed daily through: • Telnet • SNMP or BreezeCONFIG Utility • Access Unit • Black list • Preventing a radio from accessing network • Frequency Hopping - Sequence Code: • Both AU and SU share the secret code • The sequence code can be changed • Extended Service Set ID – ESSID • Max Associations
Radio Level - VL • 128 bit Wired Equivalent Privacy • Encrypts Data and ESSID • AES – Advanced Encryption Standard • Encrypts Data and ESSID • Max Associations • OFDM modulation • Extended Service Set ID – ESSID
Radio Level - LB • Point to Point operation only • Proprietary encryption based on MAC address of remote device • No broadcast of keys
Subscriber Unit Level • VLAN support - IEEE 802.1q: • Tag insertion • Out-going (SU-to-connected LAN) Packet Filtering • IP Filtering Lists
Network Service Level • Network Services: • General Internet Services - ISP • Private Networks for Telecommuters • Separate Virtual Networks for: • General Internet Services • Private Network for Each Enterprise • Each Network implements PoP to PoP security based on IPSec, Layer 2 Tunneling Protocol (L2TP)
Protocol Level • Customer requirement • To permit PPPoE only at the Ethernet Port • Advantages: • Blocks the Broadcasts • Blocks the attacks at IP level
VPN Level (RADGUARD, Check Point, etc.) • Implements IPSec standard • Most secure for banking remote access • Telecommuter • Software client running on PC – Windows 2000 • Enterprise premises • Security Server - between Router and Internal LAN • Features • Encryption • Key Management • Digital Signatures • Auditing features (Logs, Traps)
Security issue Solution Management parameters modified by entities not entitled to do so. • The system accepts management commands only from a previously defined IP addresses. ISP wants to avoid intruder SU to connect to its AU. • Authentication, ESSID, WEP. ISP wants to avoid intruder workstations to access its AU (network) from behind SU (on the LAN). • IP address filtering (SU transmits only predefined IP addresses). SU-A wants its broadcasts to reach only SU-C, not its neighbors. • SU-A and SU-C should have their own VLAN. Security Parameters
Security issue Solution SU-A does not want its broadcasts to be “heard” on the air (except ARP, to find the router on AU’s LAN). • Broadcast filtering in SU-A. • Non relaying broadcasts frames by AU. SU-A wants to stop incoming traffic from neighbors (broadcasts and unicasts). (e.g. “Network neighborhood” clicked by a user on SU-B). • SU-A should have its own VLAN (ISP should provide different VLANs to enterprises and to single users) • AU should not relay broadcasts. • SU-A should accept only frames arriving from predefined IP addresses. • SU-A should be followed by a router (users are on separate nets). • SU-A should be followed by a router and a fire wall. Security Parameters
Security issue Solution SU-A wants neighbors to be unable to “see” its traffic. • SU-A should have its own ESSID/AU (Neighbors can not synchronize with SU-A’s AU). • SU-A should have its own VLAN (unicast frames with SU-A tag are not “seen” by SU-B users). SU-A wants traffic to be protected over the Internet/Intranet. • Create VPN (tunneling + encryption). Security Parameters
Summary In This Lesson, We Discussed… • Network Considerations • Subscription Rates • Network Management and SNMP • Network Security