Working at a Small-to-Medium Business or ISP Chapter 2

Transcription

1 Help Desk Working at a Small-to-Medium Business or ISP Chapter 2 Copyleft 2012 Vincenzo Bruno ( Released under Crative Commons License 3.0 By-Sa Cisco name, logo and materials are Copyright Cisco Systems Inc. 1

2 Objectives 2

3 ISP Help Desk Organization At an ISP, there are usually three levels of customer support: Level 1 is for immediate support handled by juniorlevel help desk technicians. Level 2 handles calls that are escalated to more experienced telephone support. Level 3 is for calls that cannot be resolved by phone support and require a visit by an on-site technician. 3

4 ISP Help Desk Organization 4

5 Roles of ISP Technicians 5

6 Roles of ISP Technicians Level 3 support is usually in accordance with a Service Level Agreement (SLA). An SLA resembles an insurance policy, because it provides coverage or service if there is a computer or network problem. 6

7 Interacting with customers Basic incident management procedures must be followed every time a help desk technician receives a call and begins troubleshooting issues. Incident management includes opening a trouble ticket and following a problem-solving strategy. Problem-solving techniques include using troubleshooting flowcharts, addressing questions in a template format, and maintaining proper ticket escalation procedures. 7

8 Using the OSI model Troubleshoot the problem using a layered approach 8

9 Using the OSI model The Open Systems Interconnection model model breaks network communications down into multiple processes. Hubs work on Layer 1, switches on Layers 1 and 2, routers on Layers 1, 2 and 3, and firewalls on Layers 1, 2, 3, and 4. 9

10 Functions of layers Step 1: Upper layers create the data Step 2: Layer 4 packages the data for endto-end transport Step 3: Layer 3 adds the network IP address information Step 4: Layer 2 adds the data link layer header and trailer Step 5: Layer 1 converts the data to bits for transmission 10

11 Troubleshooting the OSI Model 11

12 Troubleshooting approaches Bottom-Up - The bottom-up approach starts with the physical components of the network and works its way up the layers of the OSI model. Bottom-up troubleshooting is an effective and efficient approach for suspected physical problems. Top-Down - The top-down approach starts with the user application and works its way down the layers of the OSI model. This approach starts with the assumption that the problem is with the application and not the network infrastructure. Divide-and-Conquer - The divide-and-conquer approach is generally used by more experienced network technicians. The technician makes an educated guess targeting the problem layer and then based on the observed results, moves up or down the OSI layers. 12

13 Layered Troubleshooting (1) Layer 1 Troubleshooting Device power turned off Device power unplugged Loose network cable connection Incorrect cable type Faulty network cable Faulty wireless access point Incorrect wireless settings, such as the SSID Layer 2 Troubleshooting Network switches and host NICs perform Layer 2 functions. Layer 2 problems can be caused by faulty equipment, incorrect device drivers, or an improperly configured switch. 13

14 Layer 3 Troubleshooting The technician verifies that the device has the proper settings, such as: Layered Troubleshooting (2) IP address within the assigned network Correct subnet mask Correct default gateway Other settings as required, such as DHCP or DNS Most common command line tools are: ipconfig/ifconfig - Shows IP settings on the computer ping - Tests basic network connectivity Tracert/traceroute - Determines if the routing path between the source and destination is available 14

15 Layered Troubleshooting (3) Layer 4 Troubleshooting Verify firewall configuration Layers 5 through 7 Troubleshooting The technician should check the application configuration 15

16 Creating and using Help Desk Records When a Level 1 help desk technician receives a call, there is a process followed to gather information The information gathering and recording process starts as soon as the technician answers the phone The information is transferred to a trouble ticket, or incident report Each person who works on the problem is expected to record what was done on the trouble ticket When a problem is resolved, the solution is documented in a knowledge-base 16

17 Customer Site procedures Step 1. Provide proper identification to the customer. Step 2. Review the trouble ticket or work order with the customer to verify that the information is correct. Step 3. Communicate the current status of any identified problems and the actions the technician expects to take at the customer site that day. Step 4. Obtain permission from the customer to begin the work. Step 5. Perform troubleshooting Step 6. Observe the results to ensure proper operation Step 7. Communicate the nature of the identified problem to the customer and obtain the acceptance Step 8. Close the trouble ticket and document the solution 17

18 Minimize Risks 18

19 Test online 19