Changing IP Address Enables Ping

Question

Level 2

214 points

Changing IP Address Enables Ping

From home, any attempt to ping our office server fails.
Until...
I change my Mac's IP address, using "DHCP with manual address".
Ping works again, and I can once again connect to the office server.
Until...
I ping it about a dozen times. After that, all pings fail again, and http connections to the office server (ONLY the office server, not any other site) time out.
Until...
I change my Mac's IP address again, using "DHCP with manual address".
I can replicate this behavior time after time. An IP address change locally suddenly opens up the server, but only for about 5 minutes, after which time I need to change my home IP address again.
What could possible be causing this?

Mac Pro 3.0 GHz FCP 7.0.2, Mac OS X (10.6.4), 16 GB RAM

Posted on Oct 21, 2010 10:26 PM

Reply

Answer 1

Oct 25, 2010 8:55 PM in response to Al Hatch

Depending on the type of firewall sitting in front of the office server it may regard multiple ping requests as hostile traffic and then create a blacklist entry.

Are you only executing the pings because you're failing to "http connect" to the Office server? Once successfully connected via http are you able to maintain the connection if you don't execute any pings?

Reply

Answer 2

Al Hatch Author

Level 2

214 points

Nov 4, 2010 10:01 AM in response to Kiwi Graham

The symptoms are even odder.
These steps are repeatable every time at any location outside of the office:
•
(1) Server works fine -- FTP, HTTP, whatever.
(2) Connect via VPN. Server becomes unresponsive.
(3) Disconnect VPN. Server still unresponsive.
(4) Toggle the Network Preference Pane.
Repeat steps (1) through (4).
•
Here's the kicker: the IP address never changes!
The "toggle" part is merely back and forth from "Using DHCP" to "Using DHCP with manual address".
"Using DHCP" assigns me 192.168.0.174. After switching to manual, I just paste in the same IP address, 192.168.0.174! It never changes, yet the server treats me differently.
Firewall is not active on the server.
How does this make sense?

Reply

Answer 3

Al Hatch Author

Level 2

214 points

Nov 5, 2010 3:14 AM in response to Al Hatch

Now this has begun to happen without any attempt at VPN.
The connection just dies after about 12 clicks on any website.
After I toggle the IP address, it lasts again for about 12 clicks.
This is surreal.

Reply