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Old 08-06-2013, 12:22 AM   #16
manikandanc
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Luckily, I had netcat on my ESX Server (Host machine). When I tried sending UDP packet from that machine, it could receive the response. Looks like it is a problem with one of the guests in that server. Will try to see whether I can get the network configuration for each of the guests and compare it..
 
Old 08-08-2013, 12:13 AM   #17
ilesterg
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Quote:
Originally Posted by zhjim View Post
If you have sane ip's for all the involved virtual machines and no iptables rules that block or deny traffic its all VMWares fault. I'd definitely check the network options of the guest machines. Like where they are attached and how and alike.
That's right, can you give a logical layout of your network (local to remote UDP), then how exactly you implemented this? (VMs and the like)
 
Old 08-08-2013, 01:25 AM   #18
manikandanc
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Quote:
Originally Posted by ilesterg View Post
That's right, can you give a logical layout of your network (local to remote UDP), then how exactly you implemented this? (VMs and the like)
I could not understand what kind of information you are expecting. Apologize for that. Still, will try to explain my setup.

Issue & its history:
We want to establish a jdbc connection to the MSSQL DB server. That was failing. On looking into the driver's source, we found that the jdbc driver was sending an UDP packet to the MSSQL DB Server. (When we send a UDP packet with a pre-defined data to the MSSQL Server, it will respond with some connection information.) After using wireshark, we came to the conclusion that, the udp packet is not received at the server side. Then we started narrowing down by trying from other machines, writing a custom UDP server and so on.

Setup:
We have two VMWare ESX Servers. One has SLES and RHEL and that too have the same issue. But, due to a hardware problem, we could not access them. For now, we'll ignore it.

On the another ESX server, we have two VMs (VM1 and VM2). Both are running RHEL. All the other settings are default. And both of the VMs use Bridged networking. (So, they have individual IPs.) And in the same network, I have a linux UDP server (Physical machine). And we have an MSSQL DB Server running in our test network. (Different subnet altogether and this is also on an ESX Server).

From VM1 and the ESX Server, I could send the UDP packet to both my physical UDP Server and the MSSQL and I could get proper responses.
From VM2, the behaviour is as mentioned in my eariler comment. This is the same behavior when I try to reach both of the machines. (MSSQL and my test UDP server)

Thanks for your response. In case you need more clarity, will try to provide them.
 
  


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