linux下HA中sendarp配置示例

NICKY.BOY

HA部署中,经常会遇到ARP问题.由于路由刷新慢,服务在切换后,client端访问出错.需要等到ARP表刷新后,才能正确访问.
解决方法就是使用sendarp.前段时间为它,捆扰好长时间.所以帖个例子出来.可以放在启动服务脚本中.

#!/bin/bash
#
# iptakeover script
#
# Simple script to take over an IP address.
#
# Usage is "iptakeover {start|stop|status}"
#
# SENDARP is the program included with the Heartbeat program that
# sends out an ARP request. Send_arp usage is:
#
#
SENDARP="/usr/lib/heartbeat/send_arp"
#
# REALIP is the IP address for this NIC on your LAN.
#
REALIP="299.100.100.2"
#
# ROUTERIP is the IP address for your router.
#
ROUTER_IP="299.100.100.1"
#
# SECONDARYIP is the first IP alias for a service/resource.
#
SECONDARYIP1="299.100.100.3"
# or
#IPALIAS1="299.100.100.3"
#
# NETMASK is the netmask of this card.
#
NETMASK="24"
# or
# NETMASK="255.255.255.0"
#
BROADCAST="299.100.100.0"
#
# MACADDR is the hardware address for the NIC card.
# (You'll find it using the command "/sbin/ifconfig")
#
MACADDR="091230910990"
case $1 in
start)
    # Make sure our primary IP is up
    /sbin/ifconfig eth0 $REALIP up
    # Associate the virtual IP address with this NIC
    /sbin/ip addr add $SECONDARYIP1/$NETMASK broadcast $BROADCAST dev eth0
    # Or, to create an IP alias instead of secondary IP address, use the
    command:
    # /sbin/ifconfig eth0:0 $IPALIAS1 netmask $NETMASK up
    # Create a new default route directly to the router
    /sbin/route add default gw $ROUTER_IP
    # Now send out 5 Gratuitous ARP broadcasts (ffffffffffff)
    # at two second intervals to tell the local computers to update
    # their ARP tables.
    $SENDARP -i 2000 -r 5 eth0 $SECONDARYIP1 $MACADDR $SECONDARYIP1 ffffffffffff
;;
stop)
    # Take down the secondary IP address for the service/resource.
    /sbin/ip addr del $SECONDARYIP1/$NETMASK broadcast $BROADCAST dev eth0
    # or
    /sbin/ifconfig eth0:0 down
;;
    status)
    # We check to see if we own the IPALIAS.
    OWN_ALIAS=`ifconfig | grep $SECONDARYIP1`
    if [ "$OWN_ALIAS" != "" ]; then
    echo "OK"
    else
    echo "DOWN"
    fi
;;
# End of the case statement.
    esac


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