Network Connectivity Issue - Can Ping 1 Device from 1 Computer, But Not From Another

I have a Linux server being installed. When attempting to connect the shared printers, we were unable to successfully ping from the Linux server to the printers. From a Windows 7 laptop or a MacBook, we WERE able to ping these printers. We've unplugged all of the printers, power cycled them, and now brought up just one of the printers. We can now ping from the Linux server to the printers, but the MacBook laptop and Windows laptop are no longer able to print the printers.

This seems like a network issue, but I've never seen anything like this. Ping responses work and then they don't work. They'll work from one computer, but not from another computer at the same time or immediately after. Does anyone have any suggestions on what else we can do to troubleshoot this?

Thanks!
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brownmetalsAsked:
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brownmetalsAuthor Commented:
After much trial and error, we finally determined that settings on the firewall were interfering with the DHCP server on Windows 2008 SBS. However, the firewall wasn't setup as a DHCP server. Some changes had been made to the firewall to allow the firewall to use 1 interface for VoIP phones and VPN connections while another interface on the firewall was used for outbound HTTP and HTTPS traffic. For whatever reason, when those commands were disabled and all traffic was routed via the 1 interface instead of splitting the traffic, everything worked fine. I'll have to work with Cisco directly to figure out why that setup created the problems on the network.

Thanks to everyone for your input.
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Aaron TomoskySD-WAN SimplifiedCommented:
Duplicate ip addresses or hostnames?
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brownmetalsAuthor Commented:
I've been very careful and have documented all the IP addresses on the network. Everything I can think of has been turned off except for the few computers and printers we're trying to diagnose. To my knowledge, there aren't any duplicate IP addresses. I'm pretty sure the hostnames are unique as well, but I'm going to double check both.
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brownmetalsAuthor Commented:
I found something interesting. My DHCP server is filling up with BAD_ADDRESS entries when I look at all of the DHCP leases. I'm running a Windows 2008 SBS Server, but I'm not clear on why these entries are appearing.
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Aaron TomoskySD-WAN SimplifiedCommented:
Do you have static ips in the dynamic range?
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delmcCommented:
The source for this error is most likely another DHCP server on the network, ensure that the sbs server is the only DHCP server by unplugging devices such as routers and the Linux server and see if the errors persist. If they do re-run the sbs wizards to attempt to bring everything back into line with how it was before.
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Aaron TomoskySD-WAN SimplifiedCommented:
Make sure dhcp is turned off on the router
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pmasottaCommented:
Wireshark could well save you all the "guessing" job.
give it a try ...
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brownmetalsAuthor Commented:
Other solutions suggestions lead me to examine all other devices including the firewall where I eventually found some unrelated commands that cause the network issue.
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