Brocade Communications Systems ICX 7250 series, Руководство по настройке

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the backup devices assume that the master device is offline. When the master device is offline, the backup device with the highest priority
assumes the role of the master device.
NOTE
The hello intervals must be set to the same value on both owner and backup devices for the same VRID.
dead interval
The dead interval is defined as the period of time for which backup devices wait for a hello message from the master device before
assuming that the master device is offline. An immediate switchover to the backup device with the highest priority is triggered after the
dead interval expires and there is no hello message from the master device. If a value for the dead interval is not configured, the default
value is calculated as three times the hello interval plus the skew time. Skew time is defined as (256 – priority)/256.
NOTE
The dead interval must be set to the same value on both owner and backup devices for the same VRID.
backup hello message state and interval
By default, backup devices do not send hello messages to advertise themselves to the master device. Hello messages from backup
devices can be activated, and the messages are sent at 60-second intervals, by default. The interval between the backup hello messages
can be modified.
VRRP authentication
The VRRP authentication type is not a parameter specific to the virtual router ID (VRID). VRRP uses the authentication type associated
with the interfaces on which the virtual router ID (VRID) is defined.
If your interfaces do not use authentication, neither does VRRP. For example, if you configure your device interfaces to use a simple
password to authenticate traffic, VRRP uses the same simple password, and VRRP packets that do not contain the password are
dropped.
In summary, if the interfaces on which you configure the virtual router ID use authentication, the VRRP or VRRP-E packets on those
interfaces must use the same authentication. The following VRRP and VRRP-E authentication types are supported:
• No authentication—The interfaces do not use authentication. This authentication type is the default.
• Simple—The interfaces use a simple text string as a password in packets that they send. If the interfaces use simple password
authentication, the virtual router configured on the interfaces must use the same authentication type and the same password.
• MD5—This method of authentication ensures that the packet is authentic and cannot be modified in transit. Syslog and SNMP
traps are generated when a packet is dropped due to MD5 authentication failure. MD5 authentication is supported only in
VRRP-E, and the device configuration is unique on a per-interface basis. The MD5 authentication configuration on an interface
takes effect for all VRRP-E virtual routers configured on a particular interface.
NOTE
Using MD5 authentication implies that the software does not need to run checksum verification on the receiving
device because the authentication code (the message digest 5 algorithm) is used to verify the integrity of the VRRP-E
message header.
NOTE
Authentication is not supported for VRRPv3.
VRRPv2 overview
Brocade FastIron Layer 3 Routing Configuration Guide
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