Overview of the Issue
If you set the VRRP configuration, the following problems may occur.
- Unintentional switching between master router and backup router occurs rarely
- Some appliances that use VRRP do not switch normally
Sorry for the inconvenience.
When configuring a system that uses VRRP, please pay attention to the above events and implement the setting described "Solution" below.
Solution
Second solution (Set the interval of VRRP Advertisement to 20 sec) has not been required since August, 2017. Please refer to "Restirction" section on following URL for more detail.
https://ecl.ntt.com/en/documents/service-descriptions/rsts/network/firewall.html#id29
On the other hand, customer is still required to operate first solution, "Please enable DHCP setting of Logical Network" in case of VRRP configuration.
[Please enable DHCP setting of Logical Network]
When the DHCP settig is "invalid", the ARP request is executed at the source address of 0.0.0.0 on ECL2.0 Network.
In this case, it is confirmed that some network appliances do not reply ARP.Please set "DHCP setting of Logical Network on which VRRP is configured to "valid ".
Please note that one IP address will be used for using this function when DHCP is enabled.
(Not required since August 2017)[Set the interval of VRRP Advertisement to 20 sec]
With the initial setting of VRRP's advertise interval, it is confirmed that VRRP communication rarely becomes unstable on ECL2.0 Network.
In this case, depending on the specification of the network appliance, communication may be disconnected at the time of VRRP switching, but it can be avoided by setting to the above value.
* Target service of ECL 2.0: Firewall (Brocade 5600 vRouter)
Please refer to Tutorial Brocade 5600 vRouter Configuration Guide for detailed configuration method of firewall.
The time taken for Backup to judge Master as DOWN is 60 seconds (20 sec * 3).