MORE INFORMATION
Depending upon the specific scenario, static routes may not be the most
efficient method of achieving IP routing. However, in smaller environments
where there are few networks, it can be less overhead than using a routing
protocol.
NOTE: The following steps assume that RRAS is installed, the Dial-on-Demand
(DOD) interfaces are properly configured, and connections are successful
between the two RRAS servers.
To add a static route, perform the following steps on both servers:
- Click Start, point to Programs, point to Administrative Tools, and click
Routing and RAS Admin. - in Windows 2000 click Routing and Remote Access.
- Double-click IP Routing to expand that object.
- Right-click Static Routes and click Add static route - in Windows 2000 click New Static Route.
The following information will be necessary to add a static route:
Destination (Network)
Network Mask
Gateway (address)
Metric
Interface
There are several reasons for wanting to add a static route to your
configuration and there are several configuration issues that can alter
what you add in the parameters above. Several scenarios are shown below to
help you configure your static routes, but these scenarios are not intended
to be a complete list of possibilities.
Scenario One: A Simple LAN-to-LAN Environment
RRAS(1) --- Modem - - - Modem --- RRAS(2)
10.10.0.1 10.20.0.1
| |
LAN(1) LAN(2)
10.10.0.0 10.20.0.0
Network Interface Card (NIC) IP parameters on:
RRAS(1) <IP> 10.10.0.1, mask 255.255.0.0, no default gateway
RRAS(2) <IP> 10.20.0.1, mask 255.255.0.0, no default gateway
RRAS(1) has a DOD named "HELLO" that dials RRAS(2)
RRAS(2) has a DOD named "HELLO" that dials RRAS(1)
NOTE: The names of the DOD interfaces above are the same for convenience.
For more information on how to name DOD interfaces, see the following
article in the Microsoft Knowledge base:
ARTICLE-ID: Configuring Routing and Remote Access Dial-Up Interfaces
TITLE : 159684
In this scenario, there are no other routers and the desired result is for
IP packets on LAN(1) to be successfully routed to LAN(2) and vice versa. In
this scenario, all computers on LAN(1) will define their default gateway
address as 10.10.0.1 (RRAS(1) NIC) and all the computers on LAN(2) will
define their default gateway address as 10.20.0.1 (RRAS(2) NIC). The table
below shows the information that should be supplied to add the static
routes for each RRAS router:
RRAS(1) RRAS(2)
Destination (Network) 0.0.0.0 0.0.0.0
Network Mask 0.0.0.0 0.0.0.0
Gateway (address) 1.1.1.1 1.1.1.1
Metric 1 1
Interface "HELLO" "HELLO"
The destination address and network mask on both routers should be all
zeroes, the gateway address should be all ones. The metric is unimportant
in this scenario, setting it to one is sufficient. It is very important to
choose the DOD interface in the drop down window that is configured to dial
the remote location.
Scenario Two: A LAN-to-LAN Environment with One Other Router
Router(A) RRAS(1) --- Modem - - - Modem --- RRAS(2)
10.40.0.1 10.10.0.2 10.10.0.1 10.20.0.1
| | | |
LAN(4) --- LAN(1) --- LAN(2)
10.40.0.0 10.10.0.0 10.20.0.0
NIC IP parameters on:
RRAS(1) <IP> 10.10.0.1, mask 255.255.0.0, default gateway 10.10.0.2
RRAS(2) <IP> 10.20.0.1, mask 255.255.0.0, no default gateway
RRAS(1) has a DOD named "HELLO" that dials RRAS(2)
RRAS(2) has a DOD named "HELLO" that dials RRAS(1)
This scenario is used to describe a remote, or satellite, office connecting
to the larger corporate network through a RRAS Server. Notice in this scenario
that the IP configuration of the NIC on RRAS(1) now has a default gateway
parameter. This means that the static route that is added to RRAS(1) will
need to be different. Instead of adding a default gateway route of 0.0.0.0,
a specific network route will need to be added to RRAS(1). The default
gateway specified on the NIC will take care of any other routing that may
be necessary. Also notice that because RRAS(2) has no other route in its
environment, it can use the same route as in Scenario One above. The
following table shows the information that should be supplied for each RRAS
router:
RRAS(1) RRAS(2)
Destination (Network) 10.20.0.0 0.0.0.0
Network Mask 255.255.0.0 0.0.0.0
Gateway (address) 1.1.1.1 1.1.1.1
Metric 1 1
Interface "HELLO" "HELLO"
Scenario Three: A LAN-to-LAN Environment with Multiple Routers
Router(A) RRAS(1) --- Modem - - Modem --- RRAS(2) Router(B)
10.10.0.2 10.10.0.1 10.20.0.1 10.20.0.2
| | | |
---- LAN(1) ---- ---- LAN(2) ----
10.10.0.0 10.20.0.0
NIC IP parameters on:
RRAS(1) <IP> 10.10.0.1, mask 255.255.0.0, default gateway 10.10.0.2
RRAS(2) <IP> 10.20.0.1, mask 255.255.0.0, default gateway 10.20.0.2
RRAS(1) has a DOD named "HELLO" that dials RRAS(2)
RRAS(2) has a DOD named "HELLO" that dials RRAS(1)
The following scenario assumes that there are two office locations with
multiple IP segments on each. The two offices are connecting through RRAS
Servers. Notice in this scenario that the IP configurations of the RRAS
NICs have default gateways configured. This means that the static routes
that are added to each RRAS Server will have to be more specific. Instead
of adding default gateway routes of 0.0.0.0, specific network routes will
need to be added to both servers. The default gateway specified on the NIC
will take care of any other routing that may be necessary. The following
table shows the information that should be supplied for each RRAS router:
RRAS(1) RRAS(2)
Destination (Network) 10.20.0.0 10.10.0.0
Network Mask 255.255.0.0 255.255.0.0
Gateway (address) 1.1.1.1 1.1.1.1
Metric 1 1
Interface "HELLO" "HELLO"
Scenario Four: Multiple RRAS Servers and Multiple Routers
Router(A) RRAS(1) --- Modem ----- Modem --- RRAS(2) Router(B)
10.10.0.2 10.10.0.1 | / 10.20.0.1 10.20.0.2
| | | / | |
---- LAN(1) ---- | / ---- LAN(2) ----
10.10.0.0 | / 10.20.0.0
| /
| /
|/
Router(C) RRAS(3) --- Modem
10.30.0.2 10.30.0.1
| |
---- LAN(3) ----
10.30.0.0
NIC IP parameters on:
RRAS(1) <IP> 10.10.0.1, mask 255.255.0.0, default gateway 10.10.0.2
RRAS(2) <IP> 10.20.0.1, mask 255.255.0.0, default gateway 10.20.0.2
RRAS(3) <IP> 10.30.0.1, mask 255.255.0.0, default gateway 10.30.0.2
RRAS(1) has a DOD named "HELLO1020" that dials RRAS(2)
has a DOD named "HELLO1030" that dials RRAS(3)
RRAS(2) has a DOD named "HELLO1020" that dials RRAS(1)
has a DOD named "HELLO2030" that dials RRAS(3)
RRAS(3) has a DOD named "HELLO1030" that dials RRAS(1)
has a DOD named "HELLO2030" that dials RRAS(2)
Notice that in this scenario, not only does each network have an additional
router on it, but the RRAS Servers dial different DOD interfaces depending
on where the packets need to be sent. This means that more than one static
route will need to be added and that each of these static routes will need
to be specific network routes. The following table shows the information
that should be supplied for each RRAS router:
First static route RRAS(1) RRAS(2) RRAS(3)
Destination (Network) 10.20.0.0 10.10.0.0 10.10.0.0
Network Mask 255.255.0.0 255.255.0.0 255.255.0.0
Gateway (address) 1.1.1.1 1.1.1.1 1.1.1.1
Metric 1 1 1
Interface HELLO1020 HELLO1020 HELLO1030
Second static route
Destination (Network) 10.30.0.0 10.30.0.0 10.20.0.0
Network Mask 255.255.0.0 255.255.0.0 255.255.0.0
Gateway (address) 1.1.1.1 1.1.1.1 1.1.1.1
Metric 1 1 1
Interface HELLO1030 HELLO2030 HELLO2030
Troubleshooting Static Routes
The following are some troubleshooting steps for static routes in a RRAS
environment:
- If the DOD connections cannot be made for some reason, the static routes
will not function. The DOD connections and modem lines must be working
before static routes over the DOD connections will work. Local routing
will still function.
- As with all routed environments, routers at each hop must have the
correct routing information in order to get packets from one side of a
network to the other. This means that adding static routes on one side
may not be useful if the destination router has no route to get the
packets back to the originating network.
- Make certain the correct DOD interface for static routes to other
networks is correctly identified. If packets are to be routed over a
DOD connection, make sure to select the correct DOD interface when
creating the static route. Selecting the NIC will not be sufficient to
initiate a DOD connection.
- Reinstallation of Windows NT Service Pack 3 over RRAS may be necessary on
your server and can result in intermittent problems with connectivity,
including routing of packets through static routes. If Service Pack 3 is
reapplied over an RRAS installation, RRAS must be updated.