Any Prometric center

Pometric Center

Passive hub will not regenerate the signal but active hub 
will regenerate the signal ....... so active hub is better.

active hub need electricity bt passive hub didnt 
active hub copy and regnerate signals but passive only copy 
signals

when did u write ur examination  and c i know about ur 
qualification

standard IP access list provides basic packet filtering 
abilities, based on the source IP address of a packet only. 
As a general rule, apply standard IP access lists close to 
the destination network to which you wish to permit or deny 
access.Standard IP access lists fall into the numerical 
range 1-99
Unlike standard IP access lists (which only allow you to 
filter packets based on their source IP address), extended 
IP access lists allow a much more granular level of 
control. Extended IP access lists allow filtering not only 
on source addresses, but also on destination addresses, 
protocols, and even applications, based on their port 
number. For example, you might choose to permit or deny a 
group of hosts from accessing a particular server, limit 
access to a telnet server to only a single host, or 
similar.Extended IP access lists are identified through 
their use of the 100-199 numerical range.

In standard access-list the range area is 0-99 but in case 
of extended access-list the range area is 100-199 and in 
standard access-list we cannot create permission on 
specific protocol like bloking the telnet or ftp......we 
can do that in extended access-list.

In standard access-list  we can filter the packet after
routing.and it will applied on destination router.its depend
only on source ip address.


but in case of extended access list we can filter the packet
before routing,and it will applied on source router,its
depend on source ip,destination ip,port and protocol.

standard access list has range area of 0-99
extended has 100-199.

Standard access list basically used to filter packets by IP
address & is basically close to the destination router.(1-99)

Extended access list is used to filter packets based on
address ,protocol & port no. dedicated for particular
services.(100-199)

Proxy ARP (RFC 1027) is a way to make a machine physically 
located on one network appear to be logically part of a 
different physical network connected to the same 
router/firewall. Typically it allows us to hide a machine 
with a public IP address on a private network behind a 
router, and still have the machine appear to be on the 
public network "in front of" the router. The 
router "proxys" ARP requests and all network traffic to and 
from the hidden machine to make this fiction possible.

Consider a router with two interface cards, one connected 
to a public network PUBNET and one connected to a private 
network PRIVNET. We want to hide a server machine on the 
PRIVNET network but have it accessible from the PUBNET 
network. The IP address of the server machine lies in the 
PUBNET network, even though we are placing the machine on 
the PRIVNET network behind the router.

By enabling proxy ARP on the router, any machine on the 
PUBNET network that issues an ARP "who has" request for the 
server's MAC address will get a proxy ARP reply from the 
router containing the router's MAC address. This tells 
machines on the PUBNET network that they should be sending 
packets destined for the server via the router. The router 
forwards the packets from the machines on the PUBNET 
network to the server on the PRIVNET network.

Similarly, when the server on the PRIVNET network issues 
a "who has" request for any machines on the PUBNET network, 
the router provides its own MAC address via proxy ARP. This 
tells the server to send packets for machines on the PUBNET 
network via the router. The router forwards the packets 
from the server on the PRIVNET network to the machines on 
the PUBNET network.

The proxy ARP provided by the router allows the server on 
the PRIVNETnetwork to appear to be on the PUBNET network. 
It lets the router pass ARP requests and other network 
packets in both directions between the server machine and 
the PUBNET network, making the server machine appear to be 
connected to the PUBNET network even though it is on the 
PRIVNET network hidden behind the router.

Connect External USB HDD to the laptop and then try to boot 
from this HDD by change the boot option in CMOS setup and 
then install windows OS.After OS installed tranfer all 
necessary file from local HDD to USB HDD.Once fully 
transfered all the files then format the local HDD and then 
install windows freshly and restore the data.