I'm unable to connect to a VNC server on a different subnet

We have a pc running VNC (on Subnet A) and we can connect without issue while on subnet B.  If I try to connect from subnet C the VNCViewer immediately closes without an error.  This happens regardless of the client machine we try to use.  I can ping/tracert to the host PC running VNC Server from any subnet, however the problem subnet C has 1 extra hop.  I've checked the FW and do not see any issues.  If I run a port scan from Subnet C it shows ports 5800 & 5900 as listening, I cannot telnet on either port to the host computer from subnet C.

Thanks!
anstechnicalAsked:
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anstechnicalConnect With a Mentor Author Commented:
The VNC host had a subnet restriction for inbound connections.  I just needed to add subnet C.
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MikeKaneCommented:
To test the connectivity you can telnet to port 5900 on the target IP.    

You should see an RFB 300.300 as a reply.  

Do you get this issue from any PC or IP on subnetC.  

I would say this is a port/ip issue on the firewall, that is what it sounds like.  Double check the firewalls.....

The Extra hop theory doesn't fly.   I use VNC acroos multiple hops without an issue.    


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anstechnicalAuthor Commented:
The telnet doesn't work on port 5900.  This issue is from any PC/IP on Subnet C.
I'll take another peak at the FW.
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MikeKaneConnect With a Mentor Commented:
If you can't telnet to 5900 then you certainly can't use the VNC services.  

If you can ICMP to it, that tells me your routing is ok, but since TCP 5900 seems to not get through, that leads me to beleive you have a firewall or Access list of some sort between you and that box.  
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MikeKaneCommented:
Very good, glad its fixed.
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