Servers Cannot Access Each Others Sites (networking)

[Guest]

Hello All,

Thx in advance for any help, I am not a network expert and am stumped at
this time.

In short my problem is that one pair of servers cannot see the websites
hosted on each other although all other computers can see both of them.

I have 3 Servers All Hosting Websites, no domains or anything, all three
have static IP addresses

ServerA - Hosted at data center
ServerB - Hosted at same data center consecutive IP addresses
BackupServer - Run from my house

I just replaced ServerA with a new machine.

Before the switch all three servers talked to each other and could see the
websites run on any of the servers.

After the switch BackupServer and ServerA cannot see or communicate with
each other at all. I.e. BackupServer cannot open the site hosted on ServerA
and vice versa.

BackupServer can see ServerB's site and vice versa. ServerB can see
ServerA's site and vice versa.

All other machines can see the sites of all three servers so the sites seem
to be operating normally.

Can anyone give me any idea of settings, configurations or anything I could
possibly look at to explain the lack of connection between ServerA and
BackupServer? Any pointers would be very helpful! Thanks much.

 

[Marnee]

Hi,

Are you using a name record (DNS) or navigating to the websites by IP
address? If name maybe BackupServer needs to have its DNS cache
refreshed.

If BackupServer's IP address changed and the websites are configured
to allow only certain IP addresses to connect then you will need to
reconfigure to allow the new server's IP address.

Try using tracetcp on port 80 from BackupServer to the other servers
and vice-versa to see where the packet is dropped.

Tracetcp can be found here:
http://tracetcp.sourceforge.net/

Marnee