VRRP, the Virtual Router Redundancy Protocol, allows two routers on the same
LAN to share a "virtual router". The virtual router is a data object that can
act as the Default Gateway and DHCP server for your network. The IP Address of
the virtual router is one of the LAN addresses, and can even match the real
Ethernet IP Address of one router (see below for details).
Once a virtual router is defined, the two real routers share control, using a
system of user-defined priority. Control of the virutal router can be static,
allowing the secondary router to take over only when the primary is removed from
the network (or powered off), or dynamic, using WAN monitoring to change from the
primary to secondary when the primary internet connection is down.
VRRP is designed to keep your connection to the world up by using two routers
on the same network. If you do not have two routers that support VRRP on your
network, this configuration technote cannot be completed.
The Ethernet IP Address of the two routers should be on the same logical subnet.
Telnet into each Netopia router's Main Menu.
Login with the user name and password. The Superuser login is required to save
changes.
If you are unsure of the IP Address, username or password of either router,
contact your network administrator.
Don't forget to press the Enter key to save any entries. Hitting the back space,
delete or tab without first hitting enter will undo any changes.
The ESC key will take you back towards the Main Menu screen.
Once you have completed your configuration, you should reboot the Netopia to
save and apply your changes.
Start with two routers, already configured to reach the internet on their own.
1. Go to Quick Menus, then go to IP Setup.
2. Go to VRRP Options, and select Add Virtual Router...
3. Select the Virtual Router ID (VRID). This is any number between 1 and 255.
The VRID is the same in both routers. For this example, we will use 13.
4. Select the Virtual IP Address. This IP Address must be on the same logical
subnet as both router 1 and router 2. For this example, we will use
192.168.1.50.
5. Select the Priority. This is a number between 1 and 255. The higher the
number, the greater the priority. No two routers on the LAN should have the
same priority. For this example, router 1 will have a priority set at 200.
**Please Note: If the Virtual IP Address is the same as the Ethernet IP Address of either router, then the Priority for that configuration will automatically be set to 255, giving that router Master status.
6. Leave Preempt Mode set to Yes.
7. Set the Advertisement Interval. This is a number between 1 and 255. It
measures how many seconds the router waits between VRRP advertisement packets
on the LAN. For this example, we will use 1, for 1 second intervals.
8. Set Enable to Yes. Select ADD VIRTUAL ROUTER NOW and hit enter. The
Virtual Router will be active after the next restart.
9. Set Monitor WAN to Yes. The router will now monitor the WAN
connection and release control of the Virtual Router if there is no working
internet connection.
1. Go to Quick Menus, then go to IP Setup.
2. Go to VRRP Options, and select Add Virtual Router...
3. Select the Virtual Router ID (VRID). This is any number between 1 and 255.
The VRID is the same in both routers. For this example, we will use 13.
4. Select the Virtual IP Address. This IP Address must be on the same logical
subnet as both router 1 and router 2. For this example, we will use
192.168.1.50.
5. Select the Priority. This is a number between 1 and 255. The higher the
number, the greater the priority. No two routers on the LAN should have the
same priority. For this example, router 2 will have a priority set of 100.
**Please Note: If the Virtual IP Address is the same as the Ethernet IP Address of either router, then the Priority for that configuration will automatically be set to 255, giving that router Master status.
6. Leave Preempt Mode set to Yes.
7. Set the Advertisement Interval. This is a number between 1 and 255. It
measures how many seconds the router waits between VRRP advertisement packets on the LAN. For this example, we will use 1, for 1 second intervals.
8. Set Enable to Yes. Select ADD VIRTUAL ROUTER NOW and hit enter. The
Virtual Router will be active after the next restart.
9. Set Monitor WAN to Yes. The router will now monitor the WAN
connection and release control of the Virtual Router if there is no working
internet connection.
When router 1 is connected to the internet, it will be the master, and if router 1 fails,
router 2 will take over as master. The Virtual Router looks like this:
