NB3720
User Manual for NRSW version 4.4
5.7.14. Redundancy
This page can be used to set up a redundant pair of NetModule routers (or other systems) by running
the Virtual Router Redundancy Protocol (VRRP) between them. A typical VRRP scenario defines a
first host playing the master and another the backup device, they both define a virtual gateway IP
address which will be distributed by gratuitous ARP messages for updating the ARP cache of all LAN
hosts and thus redirecting the packets accordingly.
A takeover will happen within approximately 3 seconds as soon as the partner is not reachable any-
more (checked via multicast packets). This may happen when one device is rebooting or the Ethernet
link went down. Same applies when the WAN link goes down.
NetModule Router Simulator
Hostname NB1600
Software Version 4.4.0.103
© 2004-2020, NetModule AG
SDK
Administration
Job Management
Testing
DHCP Server
DNS Server
NTP Server
Dynamic DNS
Events
SMS
SSH/Telnet Server
SNMP Agent
Web Server
Softflow
Discovery
Redundancy
Voice Gateway
Redundancy
Rule
Id
Interface
Address
HOME
INTERFACES
ROUTING
FIREWALL
VPN
SERVICES
SYSTEM
LOGOUT
Figure 5.48.: VRRP Configuration
In case DHCP has been activated, please keep in mind that you will need to reconfigure the DHCP
gateway address offered by the server and let them point to the virtual gateway address. In order to
avoid conflicts you may turn off DHCP on the backup device or even better, split the DHCP lease range
across both routers in order to prevent any lease duplication.
Parameter
Redundancy Configuration
Administrative status
Administrative status
150
