shabbir's Avatar, Join Date: Jul 2004
Go4Expert Founder
Will extend this for one more day if OP Agrees
techgeek.in's Avatar, Join Date: Dec 2009
Skilled contributor
Quote:
Originally Posted by venami View Post
We can drop all the ICMP requests that comes from a particular IP address using the firewall settings. So there is a possibility of the host dropping the ICMP requests from the pinging machine and responding to other machines.
let me explain you some points:-

1) as per my question the user has called up a help desk. Someone calls a help desk only when the person is unable to access a computer or service and was able to do that before.

2) If the user access to the host computer had been restricted then the help desk would have informed the user that the user has been restricted to access that computer. But instead the help desk is trying to help out the user. Mind it the help desk is belonging to the same subnet so it better knows which users has what access.

3) you point is correct that ICMP packets can be dropped based on the IP address. But you know very well that IP address verification is done in the third layer of the network that is the network layer. The devices that works in the network layer are routers, L3 switches and the computer configured with firewalls,NATing and routing. But my dear frnd the computers are belonging to a subnet. Here it is no point in doing such IP verifications. You can set logic to L2 swithches,rather, for the purpose. But in that case it is not IP, it is MAC address..nd my 1st point clearly indicates that the user is noway restricted by host computer..
techgeek.in's Avatar, Join Date: Dec 2009
Skilled contributor
Quote:
Originally Posted by shabbir View Post
Will extend this for one more day if OP Agrees
yah sure...
venami's Avatar, Join Date: Dec 2008
Ambitious contributor
What is the answer?
techgeek.in's Avatar, Join Date: Dec 2009
Skilled contributor
Quote:
Originally Posted by venami View Post
What is the answer?
answer is:- from the problem workstation, enter arp -a to refresh the ARP cache list.

explaination:- the "arp" command supports the ARP service of the TCP/IP protocol suite. It enables an administration to view the ARP cache and add or delete cache entries. Any added entry becomes permanent until it is deleted or the machine is shut down.

e.g:-
Code:
 
c:/>arp -a
interface: 192.168.1.200 ---- 0X2
Internet address                       Physical Address                 Type
192.168.1.25                         00-aa-00-62-c5-09                 static
192.168.1.50                         00-60-08-cd-34-54                 dyanamic
192.168.1.51                         00-60-08-cd-34-52                 dyanamic
Now, suppose the situation is such that the host might have been removed from the network for a few minutes and the arp cache list of the user has no MAC address info for the host computer. Then the user wud not be able to access the host. Such arp cache problem occurs most of the time while working in a network. In such situation the user needs to run the "arp -a" command to refresh the cache list untill he is getting the info about the destined host.
(note:- reply me if anyone has any sort of confusion. I know the question is very tricky and only network experts are expected to ans)