What is the best method for moving from one Layer 3 switch to a new Layer 3 switch?
Our old Layer 3 is 10/100 Mbps. We are moving to a new switch that is 10/100/1000 Mbps. Our "network consultants" told me that installing a new Layer 3 is basically " a plug and play" operation. We do not have any special configuration (VLANs for example) in our current switch.
On my first attempt, I plugged just two PCs, our (SonicWall) firewall, and both domain controllers into the gigabit Layer 3 switch. This is with the idea that if I could get a small configuration working.....then I would add the rest of the devices....and I am done.
I plugged those five devices into the new gigabit Layer 3. I could ping each of those devices among them selves.... But I just could not get to any Internet web page. I believe my problem is that the "default gateway" device was not added to my small configuration. In the past the "default gateway device" was embedded in one of the routers. Essentially all the default gateway (xx.xx.254.253) does is point the system devices (on the main subnet) to the firewall (xx.xx.254.222). If I would have been thinking at the time, I could have just changed the device gateway (on one or both of those two test PCs) to xx.xx.254.222 instead of leaving it at xx.xx.254.253. Anyway, I was running short of my "scheduled downtime"... So after not being able to connect to the Internet, I switched everything back over to original.
Now, I know changing the default gateway to xx.xx.254.222 is a good workaround (for not using the actual default gateway) because I changed one computer to xx.xx.254.222 since I returned to our original configuration. It works fine.
Anyway, I found the router that has the default gateway embedded. I could schedule more downtime and attempt to add the gateway to my same "small configuration of devices" to see if I can connect to the Internet with the gigabit Layer 3 switch. But I thought it would be prudent to see if there is a better procedure than what I am using to move over to the gigabit Layer 3 switch.