?
Solved

Internet connection issue

Posted on 2006-11-19
5
Medium Priority
?
189 Views
Last Modified: 2013-11-29
I have a computer that is used to connect to internet with no problem, but after ISA server was installed it can not connect to internet anymore.

the question is if I was not told that ISA server was installed, how would I find out the reason why the computer can not connect to internet , which tools should I use or should I have used to find out?

thanks
0
Comment
Question by:jskfan
5 Comments
 
LVL 1

Expert Comment

by:dacz
ID: 17975078
get the IP address of your ISA server and make it your proxy server address to have an internet connection.
0
 
LVL 1

Assisted Solution

by:dacz
dacz earned 140 total points
ID: 17975096
0
 
LVL 6

Assisted Solution

by:_iskywalker_
_iskywalker_ earned 140 total points
ID: 17975181
first it is nice to know if you have an ip, then if you can ping your host or gateway, then you should contact the admin of the gateway to let you go through the internet. if you can you can ping www.experts-exchange.com and see if  it works, then you can traceroute this address and see which wroute it takes.
0
 

Author Comment

by:jskfan
ID: 17975200
my question was:
 How do I know that it was ISA server  blocking access to internet if I was not told by someone else that ISA server was installed in the computer?



0
 
LVL 79

Accepted Solution

by:
lrmoore earned 720 total points
ID: 17975330
That depends. Do you mean as a single end-user only - how can you determine that something was blocking your Internet access?
or as a systems administrator, what tools can you use to determine why you can't get Internet access, and could have determined that ISA had been installed somewhere?
or as a systems administrator, what tools can you use to know when something gets installed on one of your servers without you knowing about it?

All of these are really tough questions without simple answers.
Basically, if your Internet access goes down, then start by using the good old 7-layer OSI model, ground up.
Start with Layer1 - check/test all cables, outlets, plugs, etc
Layer2 = protocol checks, vlans, packet errors (duplex mismatch) etc
Layer3 = IP subnets/routes - ping/traceroute/route print/ ipconfig
Layer4 = name resolution/DNS/ firewall rules / proxy rules - Sniffer/Ethereal
Layer5-7 = permissions, credentials and applications. What's wrong with credentials/login? What's new application wise? What changed in any applications? What's different in this system that works and that one that doesn't? Group Policy is new, etc.  Sniffer/Ethereal can help determine these type issues
Layer 8 - 9 = politics, money and religion. Who make the new rules without communicating them to the masses? What governs most changes? Money, politics and religion. (Religion in the way some are religous Microsoft fanatics, some are religously anti-Microsoft fanatics, Cisco fanantics, anti-Cisco fanatics, etc)

None of those tools may ever tell you that it was specifically an unexpected ISA server showing up that was causing the problem. You might determine the IP address/mac-address of whatever it is blocking traffic, then you'd have to manually look at that system to see what was happening.

Do you have a change management process? If you did, then it would never allow that something as potentially disruptive to production as installing ISA could happen without everyone knowing about it. There are other automated tools available to determine and report system changes.
0

Featured Post

Free Tool: IP Lookup

Get more info about an IP address or domain name, such as organization, abuse contacts and geolocation.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

If you’re involved with your company’s wide area network (WAN), you’ve probably heard about SD-WANs. They’re the “boy wonder” of networking, ostensibly allowing companies to replace expensive MPLS lines with low-cost Internet access. But, are they …
In this article I will be showing you how to subnet the easiest way possible for IPv4 (Internet Protocol version 4). This article does not cover IPv6. Keep in mind that subnetting requires lots of practice and time.
This video gives you a great overview about bandwidth monitoring with SNMP and WMI with our network monitoring solution PRTG Network Monitor (https://www.paessler.com/prtg). If you're looking for how to monitor bandwidth using netflow or packet s…
Monitoring a network: how to monitor network services and why? Michael Kulchisky, MCSE, MCSA, MCP, VTSP, VSP, CCSP outlines the philosophy behind service monitoring and why a handshake validation is critical in network monitoring. Software utilized …

807 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question