Specifications

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Cisco Wide Area Application Services Command Reference
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Chapter 3 CLI Commands
(config-if) standby
Note Interface IP addresses and standby group IP addresses must be on different subnets to ensure reliable
operation. You can use dummy IP addresses in the private address space to serve as interface primary IP
addresses, and use the real WAAS device’s IP address to serve as the standby group IP address in a
different subnet to satisfy this requirement. When dummy IP addresses are used, these interface IP
addresses serve only as substitutes to bring up the interface. For example, the WAAS device’s interface
requires an IP address on an interface for initialization. Make sure to configure the interface default
gateway using the ip default-gateway global configuration command instead of the ip route command.
• Each interface in a standby group is assigned a priority. The operational interface with the highest
priority in a standby group is the active interface. Only the active interface uses the group IP address.
• The priority of an interface in a standby group can be changed at runtime. The member interface that
has the highest priority after this change becomes the new active interface (the default action is to
preempt the currently active interface if an interface with higher priority exists).
• The maximum number of errors allowed on the active interface before the interface is shut down and
the standby is brought up is configured with the errors option, which is disabled by default.
Tip If an interface belongs to more than one standby group, you can configure the interface with a different
priority in each standby group for better load-balancing. For example, interfaces Gigabit Ethernet 1/0
and Gigabit Ethernet 2/0 are both in standby group 1 and in standby group 2. If you configure Gigabit
Ethernet 1/0 with the highest priority in standby group 1 and configure Gigabit Ethernet 2/0 with the
highest priority in standby group 2, standby group 1 uses Gigabit Ethernet 1/0 as the active interface,
while standby group 2 uses Gigabit Ethernet 2/0 as the active interface. This configuration allows each
interface to back up the other one, if one of them fails.
Note Unlike port channels, standby groups do not support IP ACLs at a group level. However, you can
configure a member interface of a standby group to support an IP ACL at the interface level. For
example, you can individually configure the two member interfaces of Standby Group 1 (the
Gigabit
Ethernet slot 1/port 0 interface and the Gigabit Ethernet slot 2/port 0 interface) to support an IP
ACL named ACL1, but you cannot configure the Standby Group 1 to support ACL1.
Examples The following example configures two Gigabit Ethernet interfaces to be part of the same standby group,
with interface 1/0 as the active interface:
WAE(config-if)# interface gigabitEthernet 1/0 standby 1 ip 10.16.10.10 255.255.254.0
WAE(config-if)# interface gigabitEthernet 2/0 standby 1 ip 10.16.10.10 255.255.254.0
WAE(config-if)# interface gigabitEthernet 1/0 standby 1 priority 300
WAE(config-if)# interface gigabitEthernet 2/0 standby 1 priority 200
WAE(config-if)# interface gigabitEthernet 1/0 standby 1 errors 10000
WAE(config-if)# interface gigabitEthernet 2/0 standby 1 errors 10000
The following example displays information about the standby group configuration by entering the show
standby EXEC command. In the following sample command output, one standby group (Standby Group
1) is configured on this WAAS device. The command output also shows which member interface is the
active interface. In this case, the active interface is the Gigabit Ethernet slot 1/port 0 interface.
WAE# show standby
Standby Group: 1
Description: This a backup for Gigabit Ethernet 2/0.
IP address: 10.16.10.10, netmask: 255.0.0.0