Service-Based Virtual Router Groups - Radware Alteon Application Manual

4. On both Alteons, enable tracking based on the number of healthy real servers behind the VIP
address. The VIP address is the same as the IP address of the virtual server router on Alteon.
Set the value to 6.
Initially, Alteon 1 has a priority of 100 (base value), plus 5 (initially it is the master), plus 24 (4
active real servers multiplied by 6, per real server), resulting in 129.
Alteon 2 has a priority of 96 (base value), plus 24 (4 active real servers multiplied by 6, per real
server), resulting in 120.
If a server attached to Alteon 1 fails, then the priority for Alteon 1 is reduced by 6, resulting in
123. Since 123 is greater than 120 (the priority for Alteon 2), Alteon 1 remains the master.
If a second server attached to Alteon 1 fails, then the priority for Alteon 1 is reduced by 6 more,
resulting in 117. Since 117 is less than 120 (the priority for Alteon 2), then Alteon 2 becomes
the master. At this point, the priority for Alteon 1 will falls by 5 more, and the priority for Alteon
2 rises by 5, because the Alteons are tracking how many masters they are running. As a result,
the priority for Alteon 1 results in 112, and the priority for Alteon 2 results in 125.
When both servers are restored to Alteon 1, its priority rises by 12 (2 healthy real servers
multiplied by 6, per healthy server), resulting in 124. Because 124 is less than 125, Alteon 2
remains the master.
If, at this point, a server fails on Alteon 2, its priority falls by 6, resulting in 119. Because 119 is
less than 124, Alteon 1 becomes the master. Its priority results in 129, since it is now the
master, while the priority for Alteon 2 drops by 5 more, resulting in 114.
Tip: There is no shortcut to setting tracking parameters. Your goals must first be set and the
outcomes of various configurations and scenarios analyzed to find settings that meet your goals.

Service-Based Virtual Router Groups

Service-based virtual router groups can be used for failover in either an active-active or active-
standby configuration.
Figure 81 - Service-Based Virtual Router Groups in and Active-Standby Configuration, page
illustrates two customers sharing the same VRRP devices configured in active-standby configuration
for VIP 1 and 2. Virtual routers 1, 2, 3, and 4 are defined on both Alteons as follows:
• Virtual Routers 1 and 3 are virtual interface routers—they use the IP interface addresses.
• Virtual Routers 2 and 4 are virtual service routers—they use the virtual server IP addresses.
Virtual Router 1 on the master forwards the packets sent to the IP addresses associated with the
virtual router, and answers ARP requests for these IP addresses. The virtual router backup assumes
forwarding responsibility for a virtual router should the current master fail.
Virtual routers 1 and 2 are members of Vrgroup 1, and virtual routers 3 and 4 are members of
Vrgroup 2.
Document ID: RDWR-ALOS-V2900_AG1302
Alteon Application Switch Operating System Application Guide
High Availability
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