My ports are suddenly blocked.

[SilentLeviathan]

I'm using uTorrent 1.6 and have a Linksys WRT54GS v4 with DD-WRT v23 SP1.

I'm getting "blocked ports" messages in uTorrent, in my user stats here and when I try uTorrent's "test my ports" tool.

Everything was woking fine last night but today everything is being reported as blocked.

I haven't changed any of my port forwarding settings and I've tried restarting uTorrent and my computer. My ports are still shown as blocked. Windows firewall is disabled, UPnP is disabled, and randomize ports is off.

I have forwarded port 1720 on my router for both TCP and UDP for the IP of my torrenting computer yet uTorrent shows it as blocked.

What puzzles me most is that nothing was changed, added, or installed yet the ports now show up as blocked.

[Ultima]

Any reason you're not upgrading to DD-WRT v23 SP2? Older versions are not recommended... Anyway, make sure you set a static IP up.

[SilentLeviathan]

Sorry, my mistake. I am using SP2.

[Ultima]

... What about setting up a static IP like I mentioned...?

[SilentLeviathan]

Yeah, static IPs have been set for all machines on my network. Still giving me the same error.

[Ultima]

Try setting the port forwarding up again on another port.

[SilentLeviathan]

I was going to try other ports but for whatever reason everything seems to be unblocked again and is forwarding properly. I am a bit wary of fiddling with it as I don't want it to suddenly start blocking ports again.

[SilentLeviathan]

Ah!!! My ports are blocked again. I tried switching to a different port but it didn't help. WTF this is getting ridiculous

[Ultima]

Did you set a static IP outside of the DHCP range in the Linksys? It will NOT accept an IP as static if it's within the DHCP range.

[SilentLeviathan]

Yeah, I did. The default rage is 192.168.1.100-192.168.1.149 so I set the IPs to values beyond that range. Still have blocked ports.

[Ultima]

What modem are you using?

[JonDrummer04]

Hi, I've been having trouble getting uT1.6 to work for me and this is the first time I've seen anyone say something about the static IP address being set outside the DHCP range. Now I don't use Linksys, I use DLink; however, I looked at the range under my DHCP Server and it's 192.168.0.100-192.168.0.199. The static IP I've been using is 192.168.0.101. So should I be using something like 192.168.0.200? Is it okay to just make an IP address like that? And do I change it in my DLink setup that I access through Firefox or should I change it in my Network Connections? Or both?

Oh, ports have been forwarded, firewall taken care of, and the exclamation point in uT is yellow. When I go to test out my port to see if it's forwarded it says it's blocked. However, since I've forwarded the port I'm thinking the static IP address might be the issue. Thanks for the help!

- Jon

[Ultima]

Yes that should be fine. But as I asked SilentLeviathan, we need to know your modem...

[mystic]

I've also been having similar problems, which I posted about here: http://forum.utorrent.com/viewtopic.php?pid=215583#p215583 (some other members are also having the same problem as well, and they have posted in my post). I was hoping since a few of us have the same problem that maybe we can try to find a solution together.

I don't know why, but it seems to be an issue with ports suddenly being blocked when nothing has been changed to the system. Everything worked great for me until one day my download rates dropped and I got the "not connected" red exclaimation mark! I have a 2wire 1800HW router, static IP, utorrent 1.6, and all my ports are forwarded correctly. I even tried using a different port number than the one I set it up originally with, but that didn't work. Please help...thanks.

[Ultima]

@mystic: Make sure that if there are multiple copies of your computer name in the custom applications list, that you try all of them.

[mystic]

As I posted in my other thread, I figured out that it was a problem with my McAfee security suite's "personal firewall plus" component. Somehow, although the problem was not present before, it caused a blockage with utorrent. I have disabled the firewall and the port is now detected as open and my download speeds have gone back up. Please check any software, such as security suites, to see if they are causing the blocked ports. It may be blocking it, even if you have not touched the settings recently. Hope this helps. Thanks everyone!

[SilentLeviathan]

I have a Motorola Surfboard 5100. It's a cable modem.

Here's the really odd thing, uTorrent seems to be working fine on my other PCs, it's just this one that it suddenly decided to start blocking the ports on.

[Ultima]

Of possible interest to you... http://forum.portforward.com/YaBB.cgi?board=Knowledge;action=display;num=1139203595

[SilentLeviathan]

I get an error when I visit that page.

[Ultima]

The main point of this thread was to say that due to a "feature" in SurfBoard modems, your computers essentially get placed behind a NAT on the modem when it loses internet connection (so that your computers can communicate with one another over the network). For whatever reason (I forget why, but this is as I remember the thread), it persists after your connection returns. Some ISPs use this "feature" to place your connection behind a NAT permanently by periodically closing the connection on the modem. Result? You can't forward your ports.

Note: Keep in mind that the symptoms described in the PortForward.com forum thread don't necessarily have to be matched exactly in order to diagnose your problem as being SurfBoard-related. The fact of the matter is, past experience has shown that SurfBoards very often cause port forwarding problems for users, and the only surefire way around it is to replace the modem with another one that doesn't try hard to be too clever (read: not SurfBoard).

The Motorola Surfboard cable modem is generally not a problem for port forwarding because it has no "router" functions in it.

However, apparently some ISPs have found a way to "remote configure" these modems to take advantage of a legitimate feature of the modem to BLOCK the ports needed for games and filesharing.

Normally a cable modem should just "pass along" everything that comes in over the cable connection, without modifying anything. But the Surfboard has a feature built-in which will provide "Private IP addresses" to all the computers connected to it if it detects the cable Internet connection has failed, or if the "Offline" button is pressed. This is to allow multiple computers on your local network to operate as a "LAN" without a connection to the Internet. It's a legitimate "safety feature" which most home users will never need. It appears however that the feature can be turned on remotely by reprogramming the modem over the Interenet connection from the ISP. This forces the modem to provide "Private IP addresses" even when connected to the Interent, and this interfers with the modem's ability to pass along the ports without blocking them.

We don't have a sample of this type of modem to actually experiment with, and we don't know exactly which ISPs are doing this, but we do know how to find out if your Motorola Surfboard has been "neutered" in this way.

There are two different setups you may have, so there are two different ways to check this, depending on how your network is set up. Do these checks when you're connected to the Internet normally.

If the Surfboard modem is plugged DIRECTLY into your computer, and you have no other devices connected between them, you need to find the IP address assigned to your COMPUTER.

We have a guide showing how to do this here:

http://forum.portforward.com/YaBB.cgi?board=Knowledge;action=display;num=1131348183

If you have a ROUTER connected between the Surfboard and your computer, you need to log into the ROUTER and check it's "Status Page" to find the "WAN IP", sometimes called "Internet IP" address. The procedure to do this will vary depending on what kind of router you have, but there's usually a Status link or tab either on the main menu or under an "Advanced" link.

Once you've found the IP address, if it starts with 192.168.100.xxx then you should suspect that your Surfboard has been modified by your ISP to block the ports you need.

If the IP address is anything else, the modem should be OK.

So- what to do if you found a 192.168.100.xxx address...?

If you call your ISP they'll most likely tell you they're not blocking any ports. That's "true", as far as it goes because it's not the ISP that's blocking them, it's the modem.

Ask them to reconfigure your modem to turn off the DHCP Server. They'll probably tell you they don't know what you're talking about. (That's probably "true" too. The people on the phone probably have no idea.)

Your only recourse if you have one of the modems that has been reprogrammed this way may be to buy a different type of cable modem, one which can't be remotely configured to do this.

NOTE- the Surfboard's IP address NORMALLY is 192.168.100.1

This is NOT the address you need to check. If you see that the "Default Gateway" in any of the reports you do is 192.168.100.1, that does NOT by itself indicate a problem.

It's the IP Address assigned to your COMPUTER or ROUTER which indicates whether or not the Surfboard has a problem.

[SilentLeviathan]

i don't think it's the modem. What's driving me crazy is the randomness of the port blocking.

uTorrent says my ports are blocked one day and fine the next. What's worse is that sometimes uTorrent gives me the red "ports blocked" icon but when I test the ports it says they are fine but other times uTorrent tests the ports and says they're blocked.

[Ultima]

And what I said is a fine example of a possible cause. If you lose your connection, your computer is suddenly placed behind a NAT. Maybe you lose your connection for long enough for the modem to place your network behind its extra NAT, but not long enough for you to notice the disconnect. Or maybe your ISP periodically forces the modem into a NAT situation. Whatever the case, it's easily/very likely the SurfBoard is the problem. After all, you've set the static IP up properly, and if you can get a green light at all, then you've forwarded your port properly as well.

[SilentLeviathan]

OK, I tried out uTorrent on the other PCs on my network, with the same settings, and it works fine on them. But I am still having problems running it consistently on this PC.

[Ultima]

If it's working for other computers on your network that have the same configuration (I assume that means all security softwares and such are identical, and configured similarly), then my only explanation is that you didn't forward the port to the correct computer.

[SilentLeviathan]

But that's the thing, right now I am getting the red exclaimation mark in the status bar but now uTorrent is saying all ports are forwarded correctly. I don't have any other instances of uTorrent running on any PCs. As well, restarting uTorrent doesn't seem to make a difference.

I double checked my settings, I am using port 1720 and this PC has been assigned IP 192.168.1.175. In the control panel in my router I have port 1720 forwarded on IP 19.168.1.175 for both UDP and TCP.