Has anyone ever encountered such a situation:

A particular computer can PING, and trace route to a Data Center. However, the same computer cannot connect to any specific ports at that DC. For Ex: HTTP, FTP or SSH.

There is no firewall, or access filter for that IP range at the Data Center either.

I tried to send data packets via tcp transfer from the DC to the computer to no avail. But the DC can still PING and trace route to the computer too, and vice versa.

The DC is located in US, while the client computer is located in Singapore.

I've never run into such a situation where a server can be pinged, but cannot connect to any ports, with no firewalls or access filters are running.

Is it possible that the upstream has something in place? or possibly other causes?

Any help would be appreciated.

Do you have any firewall such as Norton etc on the client computer in Singapore that blocks other ports. Dun think Sg ISP upstream will cause any probs. If u have firewall at the client computer end disable and check if it is ok.

No there isn't.

Actually, the singapore computer has two connections, one Cable, and one DSL.

The DSL can connect. But not the cable. Same machine.

They have different IP ranges of course. Both maxonline.

Teh DC could be blocking the one IP for DOS/etc

What DC is it?

The DC isn't blocking it, that's the first thing I checked.

I am just wondering if the upstream provider could be doing it, which is Wiltel.

Maybe there is no service running on the destination IP (posisble eh!)

If only that were the case :mad:

Have you tried connecting to the destination IP using some other OS/machine from the same network? You never know - it could be something not right with your exisiting machine?

Atleast in such a scenarion you will know that your OS is not the guilty party here.

Yes, I've tried using multiple machines, and all were able to connect to the DC.

The main machine in particular which cannot connect to that DC, is able to connect to other DCs except for this one.

I've probably tried every test possible by now. I was hoping someone had a similar experience.

If anyone from Singapore reads this, and you have maxonline cable internet, could you please try to see if you can download this file:

ftp://test:file@69.45.6.86/1.meg

I want to see if it's limited to just this particular machine or if it's a subnet.

The machine I've been testing it on has the IP 218.212.184.*

Cant save link remove or unavailable

This could be the DC upstream provider. I once seen a similar problem once where the telephone company for a ISP blocked a IP or IP range do to a hack attempt of some type.

That's what I was thinking. I'll have to look into it.

boonchuan: You meant you tried from your cable, and it timed out failing to connect?