Similar idea... It sounds like the change in the NIC hardware caused a loss of connectivity because of
The Address Resolution Protocol (ARP) information in the local router/switch’s cache.
DNS relates a name record to an IP address and ARP associates the IP address with the
Physical hardware address burned in the NIC. The router/switch still had the old address stored because
It resolves, caches, and refreshes ARP information just like DNS. A simple ARP flush probably fixed the problem.
Your description is correct below... a submitted DNS change through your data centre host
Can/will be reflected immediately after they do it for all subsequent DNS resolution requests.
All clients/end users that have previously completed a DNS resolution will have bad info cached
Until it expires and they resolve the name again. The redundancy and reliability built into the DNS
System also introduces a certain amount of latency for changes and updates.
Ed
On 5/19/10 7:57 PM, "keith smith" <klsmith2020@yahoo.com> wrote:
This is kind of fizzy to me. I'm glad you brought it up. I did experience this 6 to 9 month ago when the data center chanced the NIC card. I think they had to flush some buffers in their routers so the new MAC address could be found and cached if I recall correctly.
We are in a data center and use their DNS. So I'm thinking the request goes to the root server then to the data center's DNS and it tells the client what the IP address is. So if the Data Center's DNS is changed to point to a new IP for our domain then that would be instantaneous or would the client and everyone along the way cache the IP?