hi Terry,
What is happening is, your switch has several types of IP addresses,
--static IP (you set this)
--dhcp (a server or router sets this)
--default (if neither of the other is set) 192.168.1.254.
If the sg300 or 500 device has the default IP and you add another IP interface ( on a vlan or on a port) it will determine that static or dhcp interface is the management interface and the 'default' address will not work any more.
The workaround for this is:
When you are configuring layer 3 routing on a sg300 or 500 switch, once the switch is in l3 mode You need to:
1- give each vlan interface a static IP starting with vlan1. This can be the same as the default 192.168.1.254, but I recommend picking another address in case you decide to add another switch in the future.
2- Before setting an IP on the new vlan, assign an access port to the new vlan (so you can move your workstation to that vlan) for management if needed. vlan management --> port vlan membership. Once you assign the ip address, and your management interface goes away, move your pc to the port on the new vlan, give it a static, and reconnect to the new IP address.
3- use the console cable and CLI to configure the vlan interface, as the console port does not go down, or loose connectivity when configuring vlans.
Hope this helps,
Dan
