I am migrating nearly 20 websites from a win 2003 server to a win 2012 server. Both are VMware VM's, on different boxes, but in the same server room, and attached to the same switch.
The 2003 server has one NIC and an IP address per site. IIS is mapped one site per IP.
When I have migrated and tested each site, I remove the IP from the old server and set it up on the new server's NIC settings, and in IIS.
This works fine, but for between 10 and 120 minutes (ish) the new server is unreachable. I assume due to moving the IP to an interface with a new MAC address the routing ARP tables are wrong for some time on the network switch(es)? There is no change to DNS.
Is there anything I can do to speed this up?(sorry i cant give any more in-depth network architecture info as i dont have it, and do not have access to the switches)
In order to get the switch(es) routing table to update, the server needs to send out via its new IP, so that the new MAC can be known.
To do this I simply restarted the server - It seems on boot the NIC must send out some sort of data from all of its configured IP addresses.
ipconfig /flushdnson the client should do the trick. If it's the router that's the issue, flushing the ARP cache would work.Correction, I realized this was when changing DNS records, not moving IPs. Please disregard.