Alteon Application Switch Operating System Application Guide
High Availability
510
Document
ID:
RDWR-ALOS-V2900_AG1302
Determining VRRP Priority for Ports Outside the VLAN
Alteon checks hot-standby ports when calculating VRRP priority.
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If all hot-standby ports are up, Alteon adds 2 to the VRRP priority, and continues the VRRP
tracking calculation.
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If at least one hot-standby port is down, Alteon leaves the VRRP priority unchanged, and does
not perform a tracking calculation.
When a vADC has VRRP configured with a hot-standby port that is not part of the VLANs assigned to
the vADC, the vADC ignores this port in the VRRP priority calculation.
Alteon Extensions to VRRP
This section describes the following VRRP enhancements implemented in Alteon:
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Virtual Interface Routers, page 510
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Virtual Server Routers, page 510
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Sharing Interfaces for Active-Active Failover, page 511
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Service-Based Virtual Router Groups, page 512
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Tracking VRRP Router Parameters, page 515
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Tracking Service-Based Virtual Router Groups, page 516
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Virtual Interface Routers
At Layer 3, a Virtual Interface Router (VIR) allows two VRRP routers to share an IP interface across
all routers. VIRs provide a single destination IP (DIP) for upstream routers to reach various
destination networks, and provide a virtual default gateway.
A VIR must be assigned an IP interface, and every IP interface must be assigned to a VLAN. When
the IP interface of a VIR is down, the VIR is in the INIT state.
Virtual Server Routers
Alteon supports up to 1024 virtual server routers (VSRs), which extend the benefits of VRRP to
virtual server IP addresses that are used to perform SLB.
Virtual server routers operate for virtual server IP (vip) addresses in much the same manner as
virtual interface routers operate for IP interfaces. A master is negotiated via a bidding process,
during which information about each VRRP router's priority is exchanged. Only the master can
process packets that are destined for the virtual server IP address and respond to ARP requests.
One difference between virtual server routers and virtual interface routers is that a virtual server
router cannot be an IP address owner. All virtual server routers are renters.
All virtual routers, whether virtual server routers or virtual interface routers, operate independently
of one another. That is, their priority assignments, advertisements, and master negotiations are
separate. For example, when you configure a VRRP router's priority in a virtual server router, you
are not affecting that VRRP router's priority in any virtual interface router or any other virtual server
router of which it is a part. However, because of the requirement that MAC addresses be unique on a
LAN, VRIDs must be unique among all virtual routers, whether virtual interface routers or virtual
server routers.
Alteon VSRs with a virtual router ID (VRID) greater than 255 use a new packet format, which differs
in size and location to the VRID field. When sending advertisements using a VSR with a VRID greater
than 255, set the type to 15. Alteons that do not support the new packet format discard these
packets because VRRP currently only supports one defined packet type (type=1).
In
Figure 74 - Virtual Interface Router Configuration, page 511
, Alteons are configured as VRRP
routers. Together, they form a virtual interface router (VIR).
