Network Troubleshooting Flowchart

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Currently, this is scratch space for work materials needed to develop flowchart specific to Midd College environment.  Please do not put sensitive information here - as this is publicly available.



--very comparable to MIDD troubleshooting - step for AV software install can be skipped, watch for quarantine, penalty and/or interpretation of IP ranges useful?  Differentiate between issues to self-help and when to contact    

Problem w/ any network app? - try web browser

CM? - resolve, else IP address?

Confirm plugged directly into wall jack!  Not a hub, router, switch with wired or wireless connection!

media disconnected,, 169., - alternate jack, cable, computer? - possible jack or network problem - collect IP # (or message such as "media disconnected"), MAC address, Jack label, permission, alt. contact info

192., 10. address? - contact Helpdesk ("arp -a" information - all hardware addresses listed), MAC address, alt contact

140 address? - should be all set - if not, generally proxy, virus, or other issue - can troubleshoot in walk-in helpdesk - collect IP address

172 address? - record and determine whether wireless, registration, penalty, quarantine - MAC address

Background information for study:

7-layer network model - theoretical, but the complexity of networking, and understanding of troubleshooting steps to take come through

DHCP - basics of...

NAT - basics of... default configuration for Internet Connection Sharing and most home networking devices (alternative is 'bridged mode' - device acts as a dumb hub)

ipconfig /? - info available with /all, /release, /renew, /flushdns

arp -a


Midd-specific IP info:

169 - a computer that is connected to a locally-working Ethernet, has no access to the campus DHCP server.
192 or 10 are private network addresses. These would either be original default settings that a system came with, or (more likely) the result of a computer getting configuration information from a DHCP server other than the proper Middlebury College server. This could either be settings retained from a home network, or a machine could be a victim of a rogue DHCP server—a personal computer improperly configured to act as a DHCP server.
To find the address of a rogue DHCP server on a Windows computer open a command window and type ipconfig /all. Under the stuff it lists for Ethernet adapter, note the DHCP Server IP address. Ping that address. Then type arp –a; among the Internet Address and Physical Address pairs listed you will see the physical address corresponding to the DHCP server’s IP address. Put it in the ticket and assign to the Voter gang.
172 Network Ranges
Range VLAN Description
140.233.18x.xxx Midd_Secure Secured Wireless. Should have access to all domain resources.
172.17.xxx.xxx Registration Unregistered Computer, wired connection
172.18.xxx.xxx Quarantine Quarantined due to Infection or Ill Behavior , wired connection.
172.19.xxx.xxx Penalty Box Infected or not updated computer, wired connection
172.20.xxx.xxx Midd_Unplugged Unsecured Wireless. Internet access only.
Off Campus Student Housing
Courtesy of Peter Lubans, here is the list of off-campus houses that are being used for student housing :
The housing code is the SSID of the wireless network within each house, and for the hubs that are working, the WEP password is available by request.
Off-Campus Locations  -- need to update!!!
Location Housing Code Room Numbers
1229 South St Ext SSE 001, 201, 202, 203, 204, 205
242 College Street CL2 201, 202, 203
131 Franklin Street F13 101, 102, 201
77 Main St, Apt 1 M77 101, 102
77 Main St, Apt. 2 M77 201-1, 201-2
82 Weybridge, Apt 1 WY1 101, 102
82 Weybridge, Apt 2 WY2 201-1, 201-2, 202
82 Weybridge, Apt 3 WY3 301, 302
594 Weybridge WY5 001, 002, 003
100 South Main SM0
102 South Main SM2
Campus Wired Ethernet Subnet List 140.233.x.x

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