Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
xxx.xxx.xxx.64  0.0.0.0         255.255.255.192 U     0      0        0 eth0
0.0.0.0         yyy.yyy.yyy.yy  0.0.0.0         UG    1      0        0 eth0

*Note:  The .64 appears to be the broadcast address for this segment.

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echo "Enabling public IP address of x.x.x.x"
ifconfig eth0 down
ifconfig eth0 x.x.x.x netmask 255.255.255.192 up
/sbin/route add default gw y.y.y.y metric 1