Information Technology Reference
In-Depth Information
5. Type
arp -d
and press
Enter
, and then type
ping
www. yahoo.com
and press
Enter
. Type
arp
-a
and press
Enter
. The ARP cache should have at least two dynamic entries: One is your
server's IP address, and the other should be for your default gateway address. Notice that
there's no ARP entry for the address of
www. yahoo.com.
The entry for your server exists
because your computer had to do a DNS lookup for
www.yahoo.com
and, therefore, had to
get your server's MAC address because your server is also the DNS server. The entry for your
default gateway exists because the Ping packet had to be sent to your router to reach the
network where
www. yahoo.com
is located. Remember, the MAC address is used to deliver
a packet to a device only on the local network, whether the device is a computer or a router.
6. Stay logged on to your Vista computer and leave the command prompt window open for the
next activity.
Activity 8-5: Using the Tracert Command
Time Required:
10 minutes
Objective:
Use the Tracert command.
Description:
Internet access has been slow, so you use the Tracert command to try to determine
where the bottleneck is. This activity requires Internet access.
1. If necessary, log on to the domain from your Vista computer as Administrator, and open a
command prompt window.
2. Type
tracert serverXX
and press
Enter
. Because there are no routers between your Vista com-
puter and your server, you should get only one response line of output. Notice that three times
are displayed because Tracert sends three packets for each TTL value it uses. By sending three
packets, you can average the times to get a more accurate picture of the response time.
3. Type
tracert
www.yahoo.com
and press
Enter
. Some router hops include a name with the
router's address, and you can sometimes use this name to get an idea of the router's geo-
graphical location or ISP.
4. To speed up Tracert's results, you can tell it not to do router name lookups. Type
tracert -d
www.yahoo.com
and press
Enter
. The results are displayed considerably faster, especially if
you're several router hops away from
www.yahoo.com.
5. Close the command prompt window, and log off Vista.
Each network connection in Windows Server 2008 has protocols and services associated with
it. Figure 8-9 shows the Properties dialog box for a typical network connection. Beside each
installed service or protocol is a check box. If the check box is selected, the service or protocol
is bound (meaning it's enabled) to the network connection. If the check box is not selected, the
service or protocol isn't bound to the connection. Unbinding an item from a network connec-
tion doesn't affect the service or protocol's operation if it's bound to another network connec-
tion. The items listed in Figure 8-9 are default services and protocols installed for every local
area connection in Windows Server 2008 and Vista. Following is a description of each proto-
col or service:
•
Client for Microsoft Networks
—This service allows the computer to access Windows shared
resources by using Server Message Block (SMB). SMB is the default file and printer sharing
protocol in Windows. If this service is disabled on the network connection, the computer
can't access shared resources on other computers by using that network connection.
•
QoS Packet Scheduler
—This service allows an application to reserve network bandwidth
for high-priority traffic. Typically, the computer uses 100% of available bandwidth if run-
ning applications require it. If a video-conferencing application, for example, is running
along with file transfers, Internet traffic, and so forth, video-conferencing performance
could suffer if it gets only 5% or 10% of the total bandwidth. Using QoS, the video-
conferencing application can reserve bandwidth, ensuring that it can operate at a satisfactory
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