User's Manual

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Chapter 28 Keepalive Gateway Configuration
28.1 Introduction to Keepalive Gateway
Ethernet port is used to process backup or load balance, for the reason that it is a broadcast channel, it may
not detect the change of physical signal and fails to get to down when the gateway is down. Keepalive
Gateway is introduced to detect the connectivity to the higher-up gateway, in the case that an Ethernet port
connects with a higher-up gateway to form a point-to-point network topology.
For example, router connects optical terminal device and the line is up all the time. While the line between
modem and remote gateway is down, it is necessary to use an effective method to detect whether the remote
gateway is reachable. At present, detect gateway connectivity by sending ARP request to gateway on time, if
ARP resolution is failing, shut down the interface; if ARP resolution is successful, keep the interface up.
Only layer 3 switch supports keepalive gateway function.
28.2 Keepalive Gateway Configuration Task List
1. To enable or disable keepalive gateway, configure the interval period that ARP request packet is sent
and the retry-count after detection is failing.
2. Show keepalive gateway and IPv4 running status of the interface
1. To enable or disable keepalive gateway, configure the interval period that ARP request packet is
sent and the retry-count after detection is failing.
Command Explanation
Interface mode
keepalive gateway <ip-address>
[{<interval-seconds> | msec
<interval-millisecond >} [retry-count]]
no keepalive gateway
To enable keepalive gateway, configure IP
address of gateway, the interval period that
ARP request packet is sent, and the
retry-count after detection is failing, the no
command disables the function.