Westermo RedFox Series User Manual
Page 664
Westermo OS Management Guide
Version 4.17.0-0
assigned a virtual router identifier (VRID), see
below.
Note
The ”VRRP instance number” is a parameter only used by WeOS for
internal book keeping, e.g., when establishing VRRP synchronisation
groups (
). The VRRP instance number is not exchanged
in any VRRP message.
2. Virtual Router Identifier (VRID): Each instance is assigned a virtual router
instance identifier (VRID) in range 0-255. All routers on a LAN, acting as
virtual routers for a specific virtual IP address, must be configured with the
same VRID. That is, R1 and R2 in
b should have the same VRID, e.g.,
”33”.
Note
As of WeOS v4.17.0, a specific VRID (such as ”33”) can only be used
once per WeOS unit. Using the same VRID in a second VRRP instance
is not possible on a WeOS unit, not even on another LAN.
3. Virtual IP address (VIP): WeOS allows you to configure one VIP address per
VRRP instance. When designing your network there are some restrictions to
consider when selecting the VIP address.
❼ Select VIP in correct IP subnet: The VIP address should be in the same
IP subnet as the regular IP address assigned to the interface (e.g., the
VIP address in
b is 192.168.1.3, which is in the same subnet as
R1’s and R2’s IP addresses on that subnet).
❼ Select VIP not ”owned” by any router: Although it is possible to use an
address assigned to (i.e., owned by) a router as the VIP address, it is
recommended that a separate IP address is used.
Consider the example in
b): According to the recommendation,
the chosen VIP address (”192.168.1.3”) is separate from the addresses
assigned to R1 (”192.168.1.1”) and R2 (”192.168.1.2”).
Although discouraged, it would have been possible to chose ”192.168.1.1”
as VIP address. Being the owner of the address, R1 must in that case
be configured with priority 255, with dynamic priority disabled. More
information on VRRP priority is found in
below.
4. Advertisement interval: In VRRP, the master will announce its presence by
sending VRRP Advertisements on a certain interval. For VRRPv2 the inter-
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