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I'm having a peculiar problem, that I think I have narrowed down to VMware.

For the past one year, every once in a while we lose internet connection and not all users (about 10 users) go down at the same time, its usually one-by-one. First someone will call me and say "Internet is down" and then we would go reset the router and modem and switch and it would be working again for a while, then go down again without any pattern or replicatable sequence. We'd go repeat the steps again to get everyone in the office running again.

We called our Internet Service Provider and they constantly say, We see your modem and we see your router and from thier end everything is OK.

we replaced our router and switch and modem, twice!

Last friday, it dawned upon me, that everytime we turn on a VMware machine, this sequence of taking everyone down starts, which also explains the message that my users get for "IP Conflict Found"

So we do alot of VMware testing and lo and behold, it takes my Internet down. My Yahoo and Gtalk would continue working but www is down when the VMware machines are started.

I do use bridged networking to all the VMware machines, but I dont know what else to set it at.

now, sorry for this long rambling but anyone have any clue on how to stop this?

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migrated from Mar 29 '10 at 17:20

This question came from our site for professional and enthusiast programmers.

Please update your question instead of leaving an answer with more details, it makes it easier for everyone to give you better answers. – Vatine Mar 29 '10 at 19:01

Something somewhere is badly misconfigured -- my guesses:

  • Your VMWare machine & workstations have static IPs, and are both configured to use the same IP.
  • Your workstations are using DHCP, your VMWare system is static & using an IP in the DHCP pool.
  • You have N DHCP servers (where N > 1), and they're not doing ping-before-assignment.
    • (The problem here is N > 1, fix that.)
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You should only have one server serving IP addresses. The problem is you have two servers handing out new IP addresses to client computers.

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