CREATING A REMOTE ACCESS POLICY FOR DOMAIN ADMINISTRATORS IN THIS PROC...

13/ 100

=

13%

|

2

22ms

16/ 100 = 16%

3/ 100

=

3%

192.68.52.1

0/ 100

=

0%

|

3

24ms

13/ 100 = 13%

0/ 100

=

0%

192.68.80.1

4

21ms

14/ 100 = 14%

1/ 100

=

1%

192.168.247.14

5

24ms

13/ 100 = 13%

0/ 100

=

0%

192.168.54.76

Trace complete.

Troubleshooting the Routing and Remote Access Configuration

The most common symptom of trouble for an RRAS router is simply that the server is

not routing traffic. However, although the symptom might be simple, the cause might

not be. To begin troubleshooting, it is best to start with the most obvious possible

causes, such as the following:

■

Verify that the Routing and Remote Access service is running

Display the

Services tool on the Administrative Tools menu to verify that the status of the Rout­

ing and Remote Access service is Started. In most cases, you should set the Startup

Type selector to Automatic. If the service had been running and has now stopped

for no apparent reason, check the Event Viewer console for error messages related

to the stoppage.

■

Verify that routing is enabled

In the Routing And Remote Access console, dis­

play the Properties dialog box for your server and, in the General tab, make sure

that the Router check box and the appropriate routing option for your network

(Local Area Network (LAN) Routing Only or LAN And Demand-Dial Routing) are

selected. If your router is also functioning as a remote access server, you should

select that check box as well. If RRAS is not configured with the correct options,

you should check the other configuration parameters or disable the Routing and

Remote Access service completely and reconfigure it from scratch.

Lesson 4 Troubleshooting TCP/IP Routing

5

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45

■

Check the TCP/IP configuration settings

Just like any other TCP/IP com­

puter, a router must have the proper TCP/IP configuration settings in order to

function properly. Make sure that you’ve configured all the router’s interfaces with

the correct IP addresses, subnet masks, and other settings.

■

Check the IP addresses of the router interfaces

When you use the Routing

And Remote Access Server Setup Wizard to configure RRAS to function as a router,

the wizard creates interfaces in the router configuration using the computer’s cur-

rent interface settings. If you change the interface settings, such as the IP address

or subnet mask, you must change the corresponding setting in the RRAS interface

as well. In the Routing And Remote Services console, display the Properties dialog

boxes for the interfaces listed in the IP Routing’s General subheading and check to

see that their IP addresses and subnet masks match the actual interface addresses,

and that the interfaces show Operational status.

Troubleshooting the Routing Table

If you have configured RRAS correctly, and you are still experiencing routing problems,

another cause could be that the routing table does not contain the information needed

to route network traffic properly. The cause of this problem depends largely on

whether you use static routing or dynamic routing. If you use static routing, someone

might have deleted, omitted, or mistyped important routing table entries. If you use

dynamic routing, your routing protocol might not be functioning properly.

Troubleshooting Static Routing

Because static routing requires human beings to create all the specialized entries in a

routing table, the only possible source of problems in the routing table (excluding

hardware failures) is human error. If you have created your static routes in the Routing

And Remote Access console, you can view and modify them there by selecting the IP

Routing’s Static Routes subheading in the console tree (see Figure 5-10). Note, how-

ever, that doing this displays only the static routes you have created in the Routing And

Remote Access console.

Important

If someone has created static routes using the Route.exe command line utility,

these routes do not appear in the Routing And Remote Access console’s Static Routes dis­

play, nor do the default entries in the routing table appear. The only way to modify or delete

routing table entries created with Route.exe is to use Route.exe.

Figure 5-10

The Static Routes display in the Routing And Remote Access console

To display the entire routing table for the computer using the Routing And Remote

Access console, click the Static Routes subheading and, on the Action menu, click

Show IP Routing Table, to produce a display like the one in Figure 5-11. You cannot

modify the routing table in this display, however, just view it.

Figure 5-11

The RRAS IP Routing Table window

The Route.exe command line utility enables you to view, add, modify, or delete any

entries in the computer’s routing table, regardless of how you created them.

Tip

Although it might take you a bit of time to get used to its command line syntax,

Route.exe is a much better tool for creating static routes than the Routing And Remote

Access console. For example, if you try to create a routing table entry with a gateway address

that does not exist on one of the router’s connected networks, Route.exe refuses to create

the entry and displays an error message. The Static Route dialog box in the Routing And

Remote Access console allows you to create this incorrect table entry without complaining.

Lesson 4 Troubleshooting TCP/IP Routing

5

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47

Troubleshooting Routing Protocols

If you use dynamic routing, the lack of the proper entries in a router’s routing table is

the result of the routing protocol failing to put them there. Assuming that no network

communications problem is preventing the routers from exchanging messages, it is

likely that the routing protocol on one or more of the routers is not configured prop­

erly. To verify the functionality of the routing protocol, use the following procedures: