Configuration

The settings for VRRP can be found in LANconfig under IP router > VRRP.

Command line: Setup > IP-Router > VRRP





In order to configure failover or load balancing with VRRP, the following parameters can be set:

VRRP activated
This switches the VRRP module on or off (default: Off).
VRRP list
In the VRRP list, up to 16 virtual routers can be defined.




Router ID
Unique ID for the virtual router. Values between 1 and 255 are possible. The router ID is used to consolidate several physical routers into a single virtual router or a standby group.
Router IP
IP address for the virtual router.
Important: All routers on which the virtual router is set up must assign this router the same IP address.
Main priority
The main priority of the virtual router with regard to routers with several interfaces refers to the main interface, i.e. with routers with DSL and ISDN support to the DSL interface. Values between 0 and 255 are permitted. The values 0 and 255 have special meanings:
  • 0 turns the virtual router off.
  • '255' is only accepted when the virtual router address is identical to the address of the interface that is connected to the router. In other cases, the priority is automatically lowered.
Backup priority
The backup priority of the virtual router refers to the interface for which a backup connection is configured, i.e. with routers with DSL and ISDN support to the ISDN interface. Here again, values between 0 and 255 are permitted. The values 0 and 255 also have special meanings here:
  • 0 disables the virtual router in the backup event. Checks are conducted regularly in order to determine whether or not the standard connection can be reestablished. The inspection interval is defined in the reconnect delay.
  • '255' is only accepted when the virtual router address is identical to the address of the interface that is connected to the router. In other cases, the priority is automatically lowered.
When the backup connection cannot be established in backup mode, then the virtual router logs off completely and attempts to reestablish the standard or backup connection in intervals defined by the reconnect delay.
Remote site
Name of the remote site that controls the virtual router behavior. The remote site can still also be assigned to other virtual routers.
Note: Entering the remote site is optional. Linking the backup requirement to a remote site allows the use of the LANCOM-specific enhancement to VRRP not only to secure against device failure (VRRP standard) but also against interface failure or disruption at a remote site.
Comment
64 character-long commentary describing the virtual router.
Reconnect delay
This specifies the number of minutes before a virtual router that has logged off attempts to reestablish its main connection. The router remains logged off during this connection attempt. It is only broadcasted with its main or backup priority after the connection has been established successfully. The default value is 30 minutes.
Advert. interval
The advertising interval shows how many seconds until a virtual router is propagated again. The default value is 1 second.
Note: With a propagation time of 1 second, the routers in the VRRP group can change quickly when a device or interface fails. An interruption of this type will usually remain undetected due to the fact that the TCP connection is not interrupted. Other routing protocols require up to 5 minutes or longer in order to conduct the transfer to a backup router.
Master holddown time
If a time is configured here, the virtual router changes to the "Hold-Down" state as soon as the monitored WAN connection is terminated with an error and the backup delay expires (i.e. switches to backup state). In the "Hold-Down" state, the monitored WAN connection can no longer be established. Also, no further VRRP advertisements will be sent. As soon as the "Master-Holddown-Time" expires, the virtual router transitions to the "Standby" state, in which the monitored WAN connection can be reestablished. The "Master-Holddown-Time" is a string with a maximum of 6 characters, which may include the digits 0-9 and a colon. This allows the entry of times of up to 999 minutes 59 seconds (999:59). If there is no colon (e.g. "30") then the specification is interpreted as minutes. In this case the maximum is "999". If a colon is present, the colon must be followed by two characters that are interpreted as seconds. The maximum possible value here is "59". Correct time specifications are, for example "5" (5 minutes), "5:30" (5 minutes, 30 seconds) or "0:30" (30 seconds). A value of "0" or "0:00" disables the Master-Holddown.
Propose internal services on the virtual IPs
This check box controls how the device should behave when it is addressed via a virtual router address.
  • When enabled, the device reacts to certain services exactly as if it had been addressed via its actual address. Naturally, this only occurs when the device itself is the master of the virtual router. The behavior of the DHCP server changes simultaneously.
  • When disabled, the switch acts RFC compliant, i.e. packets are dropped silently.

www.lancom-systems.com

LANCOM Systems GmbH | A Rohde & Schwarz Company | Adenauerstr. 20/B2 | 52146 Wuerselen | Germany | E‑Mail info@lancom.de

LANCOM Logo