Virtual IP is configured and its able to ping from outside network., But after reboot its not

SUSE Linux Enterprise Desktop SLED Networking
1

Virtual IP is configured and its able to ping from outside network., But after reboot its not listing in ifconfig -a.,
We have updated the Virtual IP under /etc/sysconfig/network/ifcfg-eth0-1

2

Do you mean IP alias? If it is IP alias then you need to configure in ifcfg-eth0. Could you please past configuration here
/etc/sysconfig/network/ifcfg-eth0-1
You can use yast also to configure additional IPs on NIC