CIS Blocking TV Internet Connection - Rule Help Needed?.

Hi people, I have just bought a new TV which has an LAN connection and able to connect to YouTube, BBC i-player and Panasonics own 3D channel. I have a cable broadband connection via my ISP Virgins cable modem which is connected to my PC. Today I took out of my toolbox an 8 ported Mercury KOB SDH8P fast ethernet switch which I had used previously to connect two PC’s to when my son lived at home. I wired it up with the Virgin ethernet cable going to port 1 on the switch and an ethernet Cat 5E patch cable going from port 2 to the PC and another ethernet Cat 5E patch cable going from port 3 to the ethernet connection on the Blu-ray Home Theatre in a Box unit I use as a master control for the TV.

When I had it all ready I switched it all on and on signing in to the PC got a Windows has detected a new network pop up which I okayed. I then found that I had no internet but quickly found out how to correct that. Although I am online via the PC I cannot get the internet to work on the TV unit. It attempts to connect and then I get a Windows error report saying,

Windows has detected an IP address conflict. Another computer on this network has the same address as this computer. Contact your network administrator for help.

I then spent a couple of hours between Google and the Virgin help line trying for a remedy without any luck. I had earlier looked in the set a new trusted application option in the Firewall section but couldn’t see any mention of the switch there. I came to the conclusion that somehow it must be Comodo which is causing the block I then thought to look and see if any new rules had been fired and found the following which I enclose as attachments below. Can anyone tell me how to set a rule or rules in order for me to get my TV online sharing my broadband connection?. By the way my OS is Windows 7 and any help offered much appreciated.

[attachment deleted by admin]

I’m surprised you have Internet connectivity at all. The ‘Home’ zone you’ve allowed does not allow for a valid IP address from your provider, it actually caters for the APIPA addresses range, which usually kick in when a DHCP server cannot be found.

It’s probably worth taking the setup step by step, making sure you have a valid connection as you change things. Start by deleting the ‘home’ zone and the rules it created for System and Global, then start again with just the PC/Switch/Modem.

Thanks for your reply Radaghast, I did as you said and deleted the rules in the three screenshots. It now looks like the attachment below. Can you tell me what the default rule for system as in the screenshot should be?. Thanks.

[attachment deleted by admin]

It really depends whether you’re behind a router/NAT device or not. If you are, CIS should detect the network and offer to create the zone, the same way it did when you created the earlier zone. The difference will be the IP address range used. Usually, this will be something like 192.168.x.x/ or it may be a range beginning with 10.x.x.x. If you’re behind a modem only, you shouldn’t need to create any rules for the System process, as it’s covered by the default Windows System Applications rule.

I don’t have a router just the cable modem box going into the switch and then from the switch to the PC and TV. After deleting the rules as advised I still cannot get online through the TV. my internet connection is working on the PC but when I go through the connection process on the TV’s Network menu it tells me it tells me I am connected but cannot find an IP address?.

I thought maybe I should add the switch as a new trusted application but I cannot see the switch anywhere on Comodo Firewalls running applications list to add it?.

It’s possible Virgin only allocates a single IP address for your use and it may be associated with the MAC address of the PC. That’s something you’d need to check with your provider. Personally, I’d suggest getting a router, it makes life much easier if you want to connect multiple devices to the Internet.

Out of interest, can you connect the TV alone and see if it gets an IP address, if so, is it the same as the IP address you get when you connect the PC?

You don’t really add hardware devices as ‘trusted’ you add the network to which the device is attached. But if you have a direct connection to the Internet, there’s no network, per se, to trust.

Would that explain why I can see no mention of the TV on my PC?. I remember a couple of years back when I was running two PC’s from my broadband connection using this same switch and I am sure I could also see my sons computer mentioned on mine. Would a clean install of Comodo help?. I cannot understand why I can get online with my PC but not the TV. Would the switch be OS specific ie when I had two PC’s on it previous it was on my old XP Home PC and not this Windows 7 PC I have now?.

I think it’s worth taking a step back for a moment. When you connect the PC to the cable modem, what kind of IP address do you get - use ipconfig /all from a command prompt. Does it fall within one of the following ranges? – – –

My IPv4 address begins with 81.98. and then two blocks of 3 digits if that is what you mean

Ok. I just wanted to check if the cable modem was anything more than that, but it appears not. So, if you disconnect the PC and plug the modem directly into the LAN port of the TV, what happens?

Right Radaghast, I did what you said and bypassed the switch connecting the tv lan cable directly to the cable modem and was connected to the internet on the TV immediately. There was a software update available for the TV and I let it download and install, then checked YouTube and a couple of the other external links and it is all working. So I switched the switch cables back to the way they were and now I have internet access on my PC but not on the TV. My first thought was that it must be the switch but it cannot be that as then I should not be able to get online with the PC. Any ideas what the problem could be now?.

I talked to a tech at my Virgin ISP’s call centre and after I explained the problem he said that the switch is not assigning a different ISP address to each application, therefore there arises an error when both apps are trying to share the same ISP address. Do you know of a work round for this?. If the only solution is a new one what would be best a switch or a router taking into consideration I prefer wired to wireless?.

Most broadband modems, by default, only assign a single IP address, hence the problems you’re having. Just out of interest, did you ask Virgin if they’re able to provide more than one IP address? Failing that, and I personally believe a better solution, is to go with a router.

As far as recommendations, it really depends how much you want to spend. best I can do is point you towards some information. Remember, whichever router you decide to buy, make sure it’s IPv6 capable. You may not need it now, but it’s coming and I’m sure you won’t want to buy new hardware a year from now. Here’s some links:

Windows 7 Compatibility Centre
DSL and Cable Modems

If I’m right you’re in the UK, so I’d recommend either:


If you buy something with a Broadcom chip, you can probably upgrade the firmware to sohething much better, such as DD-WRT OR Tomato which I use.

Thanks a lot for your help again Radaghast, it’s much appreciated. The Virgin tech said I would get a free router if I upgraded my broadband from its present 10MB to the 30MB and as they are in the process of doubling all their customers broadband for free I would have a 60MB connection within a year. I am in the UK and will check out your links and weigh up whether I should just bite the bullet and upgrade insatead, again thanks.

I have been looking at the one in the link as a possible Firstly it is made for a cable/DSL system like Virgin and secondly I have a Buffalo external hard drive which is rock solid. All the routers I see are advertised as wireless, but are they also capable of a wired connection which I prefer or do I also have to buy a bunch of USB radio links for my apparatus?. Excuse my ignorance but I came to computers late in life.

Can’t say I know much about Buffalo products but it seems quite inexpensive. On the face of it, it doesn’t seem to support IPv6 natively, but it appears you can replace the firmware with dd-wrt, which would give you IPv6 and many other options. However, that’s a future thought.

Most wireless routers have a four port switch built-in, so you’re free to use either a wireless connection or a wired connection, which I also prefer. The only time wireless gets activated around here is when the kids are home from college. If you’re going to use a wired connection only, don’t forget to disable the wireless capabilities.