router terminology

Question

Have a Dell 2350 router. I am having trouble connecting to my TIVO DVR through my network. TIVO rep says I must have ports that are blocked by the router. My goal, obviously, is to open those ports. This gets me to my question.
On the TIVO screen I have 3 options that sound similar. What is the difference between
Advanced Filtering of ports
Port Forwarding
Port Triggering.
Which of these do I use to open ports from one IP address to another?
I have tried reading the Help info but I am still confused.
Bonus question - is there any test I can run to see if ports are actually blocked by the router or by the PC?

NemesisDB · Answer

Note: I have never used TIVO   Second Note: I'm a little confused why those screens would appear on TIVO if it's not your router.   Consider placing the TIVO's IP address in the DMZone of your router.  That should effectively forward all ports.   For reference, port forwarding on your router will typically forward an inbound communication (i.e. one from outside of your LAN) on the port you specificy to a particular IP within your LAN.   Port triggering is a bit different.  For it to work you setup a trigger -- say a LAN IP address sending outbound traffic on a given port.  When that happens, it will trigger a specific port forwarding as described above.  This can be useful because with port fowarding by itself you can only send inbound traffic to a single machine.  With port triggering, it can dynamically happen across several IPs (though it would likely get messy if multiple machines were triggering at the same time).   Lastly, if both the TIVO and the router are UPNP compliant, and UPNP is enabled on your router, the TIVO should be able to dynamically tell the router which ports it needs forwarded, when it needs them

Jay Lunis · Answer

Yeah, my fault on the screen. I meant the router screen - not TIVO.
Tried the DMZ idea. Didn't work. TIVO still complains of a 'network problem.'
The TIVO rep continues to argue this is a router problem. Is it possible, though, the ports are blocked by the PC?
How can I confirm specific ports are blocked or stealthed or in use?
Is it possible to find out what has the ports blocked or stealthed or in use?
(I have already unistalled Norton Firewall and disabled Norton Antivirus and Windows Firewall. With this done I still get complaints from TIVO of blocked ports.)
Or, if you have another idea how to open ports on the router, I'm willing.

NemesisDB · Answer

alright, let's discuss here (cause I'm really not sure how TIVO works).

A router typically blocks incoming connections from the internet unless a computer on your home LAN initiated the connection. Typically the router does not block any outbound ports -- meaning that any device on your LAN can send data over any port to the internet.

Putting the TIVO in the DMZ effectively unblocked all inbound traffic to the TIVO as well. The only way to test this would be to get outside of your LAN and trying to communicate with the TIVO. Alternatively, can you try connecting the TIVO directly to your internet connection -- if it works, then likely the router is at fault. I'm not sure if this is logistically possible given your setup, but it's a good troubleshooting step.

Is TIVO supposed to communicate with your computer? I'm a little unclear how a firewall on your computer would matter in the least -- but if you want to clarify what your setup is or what the TIVO is talking to, that might help

Jay Lunis · Answer

Thanks for the repsonse.
Tivo communicates 3 ways. (Remember, it has a wireless adapter.)
1) "Calls out" to Tivo corp. to update progam lists. I does this through the adapter to the router to the cable modem. Works perfectly.
2) Communicates to the laptop (it is wireless). From my laptop I can download shows from the TIVO DVR and watch them. Works perfectly.
3) Communicates to the PC (it is wired to the router). From my PC I should be able to download shows from the TIVO DVR and watch them. Doesn't work. TIVO sw complains of a network error.
FWIW, the laptop and PC can communicate and share files.
TIVO rep says the router needs to be set to allow TIVO but couldn't tell me how. I find this odd. I would think if TIVO can get outside the network and work with the laptop it should also work with the PC. Does this help?

NemesisDB · Answer

yeah ... firstly, I would remove TIVO from your router's DMZ as that doesn't seem to be the problem and it's a security risk.

it sounds like a problem with the PC in question -- other than removing all software firewalls on that machine, I really don't know what to suggest. if the tech tells you that again, you might want to inform him that lan to lan data doesn't really pass through the router, only the 4 port switch.

Jay Lunis · Answer

Already ended DMZ.
My inclination has recently become 'it is not a router problem.' Thanks for the confirmation from someone who knows a quite a bit more than I do.
Obvious followup question. Since I have literally uninstalled Norton Firewall and have disabled Norton AntiVirus and Windows Firewall only to see the problem persist, Where is the best place to look for guidance? Dimension forum?

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router terminology

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