RHEL/CentOSでネットワークインタフェースの起動が遅い原因を調べてみたを見て。いつからそうなってたんだろ？と。Red Hat Linux 7.xから入ってたんだろうね、このarping。
$ grep -n 'arping.*-w 3' rhel[2-6]*u0/pre-build/initscripts*/sysconfig/network-scripts/*
rhel2u0/pre-build/initscripts-6.47/sysconfig/network-scripts/ifup:205: if ! arping -q -c 2 -w 3 -D -I ${REALDEVICE} ${IPADDR} ; then
rhel3u0/pre-build/initscripts-7.31.6.EL/sysconfig/network-scripts/ifup:306: if ! arping -q -c 2 -w 3 -D -I ${REALDEVICE} ${IPADDR} ; then
rhel4u0/pre-build/initscripts-7.93.11.EL/sysconfig/network-scripts/ifup:366: if ! arping -q -c 2 -w 3 -D -I ${REALDEVICE} ${IPADDR} ; then
rhel5su0/pre-build/initscripts-8.45.14.EL/sysconfig/network-scripts/ifup-eth:242: if ! arping -q -c 2 -w 3 -D -I ${REALDEVICE} ${IPADDR} ; then
rhel6u0/pre-build/initscripts-9.03.17/sysconfig/network-scripts/ifup-eth:251: if ! /sbin/arping -q -c 2 -w 3 -D -I ${REALDEVICE} ${IPADDR} ; then