Brocade Virtual ADX Server Load Balancing Guide (Supporting ADX v03.1.00) - Manual (Page 141)

Brocade Virtual ADX Server Load Balancing Guide 125
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Miscellaneous options
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percentage threshold is not configured), then the VIP port will be declared unhealthy. If you have
configured the option where a VIP should be considered healthy if at least one VIP port is healthy,
then the Brocade Virtual ADX will check if there are any other healthy VIP ports. If there are none, it
will delete the VIP route. If you have not configured this option (a VIP should be considered healthy
only if all VIP ports are healthy), then the Brocade Virtual ADX will delete the VIP route.
Similarly, when a real server port transitions from the failed to the active state, the Brocade Virtual
ADX will check if the real server port is bound to a VIP port whose VIP has the RHI feature enabled.
If this is the case, the Brocade Virtual ADX will determine how many real server ports bound to the
VIP port are healthy. If you have configured a percentage threshold, and if this number is above the
threshold, then Brocade Virtual ADX will declare this VIP port healthy. If you have not configured a
threshold, then the Brocade Virtual ADX will declare this VIP healthy. If you have configured the
option where a VIP should be considered healthy if at least one VIP port is healthy and the VIP was
previously unhealthy, then it will inject the VIP route. If you have not configured this option (a VIP
should be considered healthy only if all VIP ports are healthy), then the Brocade Virtual ADX will
check if all other VIP ports are healthy. If they are, the Brocade Virtual ADX will inject the VIP route.
Configuration considerations
Before you enable RHI, consider the following three issues:
• Static route redistribution — It is required to redistribute the host route for the VIP into OSPF or
OSPFv3. To enable redistribution of static routes for IPv4, enter commands such as the
following:
Virtual ADX(config)#router ospf
Virtual ADX(config-ospf-router)#area 0
Virtual ADX(config-ospf-router)#redistribution static
Syntax: [no] redistribution static
To enable redistribution of static routes for IPv6, enter commands such as the following:
Virtual ADX(config)#ipv6 router ospf
Virtual ADX(config-ospf6-router)#redistribute static
Syntax: [no] redistribute static
• Disabling network route advertisement for an interface associated with VIP RHI — The ip
dont-advertise or ipv6 dont-advertise commands configure the Brocade Virtual ADX to block
advertisement of the network on the interface. If you do not block advertisement of the
network, the Brocade Virtual ADX will advertise a route to the network containing the VIP, even
if the VIP itself is unavailable. After you enter the ip dont-advertise command, the Brocade
Virtual ADX advertises only a host route to the VIP address. Therefore, if the VIP is not healthy,
the Brocade Virtual ADX will remove the static host route for the VIP address and also not
advertise a network route for the network containing the VIP address.
NOTE
When using the dont-advertise commands, the IP or IPv6 and subnet mask length should be
the same as the interface IP or IPv6 and subnet mask length.
For IPv4, enter commands similar to the following.
Virtual ADX(config)# interface ethernet 1
Virtual ADX(config-if-e1000-1)# ip address 10.1.1.99 255.255.255.0
Virtual ADX(config-if-e1000-1)# ip dont-advertise 10.1.1.99 255.255.255.0
Syntax: ip dont-advertise ip-addr mask I ip-addr/mask-bits