User`s guide

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secondary host is tried. This is to ensure that should the primary host become
unavailable for any reason and stops responding to the ICMP echo requests, the router
will check an alternative IP address before initiating the failover procedure. The value in
the second text box is the number of pings that should be allowed to fail before checking
the secondary IP address.
Ping responses are expected within s seconds
When the value in this text box is set to a non-zero value, the router will wait for that
specified interval for a response from a ping request before applying the timeout
specified in the “Send pings every ... if ping responses are not being received”
setting above. If the value is set to 0 (the default) then the router applies the timeout
without modification.
Only send Pings when this interface is “In Service”
When checked, this checkbox causes the router to only send ICMP requests when the PPP
instance is in service. The default setting is unchecked which means that ICMP requests
are sent when the interface is in service and out of service.
New connections to resume with previous Ping interval
When checked, this checkbox causes the router to use the ping interval that was in force
when the PPP interface last disconnected.
Reset the link if no response is received within s seconds
The value in this text box specifies the period for which the router should wait before
terminating the PPP connection if no response to the auto-pings has been received. This
behaviour is useful in the attempt to re-establish communications, since the router will
automatically attempt to restart an always-on link that has been terminated. This
function is primarily used where IP traffic is being carried over a W-WAN link and where
the associated PPP instance has been configured into the always-on mode.
Use ETH 0 IP address as the source IP address
When checked, this checkbox causes the router to use the IP address of interface ETH 0
as the source address for ICMP echo requests instead of the current IP address of the
PPP interface.
Defer sending pings if IP traffic is being received
One of the uses for sending ICMP echo requests is as a keepalive mechanism. When this
checkbox is checked, it causes the router to defer sending the ping packets out if IP
traffic is being received, since in this case, separate keepalives are not needed.
Limit the data transmitted over this interface
Some service providers impose a (usually monthly) limit on the amount of data sent over a
link and levy additional charges if the limit is exceeded. This is fairly common practice for
W-WAN links. When checked, this checkbox causes the router to stop sending data on the
interface when the preset data limit has been exceeded. The interface is unlocked manually
by clicking the “Clear Total Data Transferred” button on the Management – Network
Status > Interfaces > Advanced > PPP > PPP n page. Alternatively, it may be reset
automatically on a certain day of the month – see below.
Issue a warning event after n Kbytes/Mbytes/GBytes
The value in this text box is the amount of traffic which will cause a warning event to be
generated in the event log stating that the specified amount of data has been
transferred. The units are specified by a drop-down list, having the following options;
KBytes, MBytes, GBytes. For example, if the monthly tariff includes up to 5MB of data
before excess useage charges are levied, it would be useful to set this threshold to 4MB.
This would cause the router to create a warning entry in the event log once 4MB of data