Cisco 350XG series Administration Manual page 396

IP Configuration: VRRP
Configurable Elements of VRRP
NOTE
Cisco 350XG & 550XG Series 10G Stackable Managed Switches
• IPv4 VRRPv3 and VRRPv2 based on RFC5798. VRRPv3 and VRRP v2
messages are sent.
• IPv4 VRRPv2 based on RC3768. VRRPv2 messages are sent.
Configuring the VRRP version is per virtual router. The default is VRRPv2.
The following cases might occur when configuring a virtual router:
• All the existing VRRP routers of the virtual router operate in VRRPv3. In this
case, configure your new VRRP router to operate in VRRPv3.
• All the existing VRRP routers of the virtual router operate in VRRPv2. In this
case, configure your new VRRP router to operate in VRRPv2.
• If there is at least one VRRP router of the virtual router operating in both
VRRPv2 and VRRPv3. In this case, configure your VRRP router to operate in
VRRPv3 even though VRRPv2 is also interoperable.
If there are VRRPv2 only routers and VRRPv3 only routers in the virtual
NOTE
router, you must configure at least one VRRPv2 and VRRPv3 router.
When both VRRPv2 and VRRPv3 are enabled on a VRRP router, the VRRP router
transmits both VRRPv2 and VRRPv3 packets. According to VRRPv3 standards,
enabling both VRRPv2 and VRRPv3 should be done when upgrading from v2 to v3.
Mixing the two versions should not be considered as a permanent solution. Please
refer to the VRRPv3 standard for details on VRRPv2 and VRRPv3 inter-operation.
Virtual Router IP Addresses
Each virtual router is assigned one or more IP addresses for which the current
master assumes responsibility.
A VRRP router supporting a virtual router must have an IP interface on the same IP
subnet with respect to the IP addresses configured on the virtual router.
Assigning IP addresses to a virtual router is done according to the following rules:
• All the VRRP routers supporting the virtual router must be configured with
the same virtual router IP addresses in their configuration of the virtual
router.
• None of the IP addresses can be used in another virtual router, or in VRRP
routers that are not supporting the virtual router.
• One of the VRRP routers supporting the virtual router must be the owner of
all the IP addresses of the virtual router. A VRRP router is the owner of the IP
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