Pedro3 Posted February 20, 2012 Share Posted February 20, 2012 Hello? Sometimes I see this happening: the Modem / Router is working OK with all the computers, but somewhere in time the Internet just stops working with one or many or all of the computers (most often with macs, but this also happens with Windows machines). In many cases the solution is to insert a DNS server in the computers that have IP, etc but don't access the internet, just after I insert the DNS, the computer can access Internet with no problem. Is a problem in the Router or in the Computer? Yesterday it happened exactly this case. 2 Macs fail to access the Internet (by Wi-Fi), with the Ethernet cable connected they can access the Internet, but not with Wi-Fi, after I inserted the DNS Servers, it connected (with Wi-Fi). Do the Routers have some place where I can control the sending of the DNS servers to the computers? Link to comment Share on other sites More sharing options...
xendrome Posted February 20, 2012 Share Posted February 20, 2012 Putting the DNS servers into the settings might just be resetting the IP stack and fixing the issue... Give some more info, what modem/router do you have? Link to comment Share on other sites More sharing options...
+BudMan MVC Posted February 20, 2012 MVC Share Posted February 20, 2012 DNS server are sent to the client via the DHCP server on your router.. I assume your router is acting as the dhcp server. And I would assume that its setting itself as the dns server. Many soho router dns forwarder is lacking to say the least, and yeah they can become unresponsive sometime. I just run my own local dns that directly queries for dns. So you could go that route, or just point your clients to either your isp dns. Or any other public dns, like googledns or opendns or 4.2.2.2 which dns that anyone can query. Link to comment Share on other sites More sharing options...
Pedro3 Posted February 20, 2012 Author Share Posted February 20, 2012 Putting the DNS servers into the settings might just be resetting the IP stack and fixing the issue... Give some more info, what modem/router do you have? In the case of the 2 macs, it's a netgear (can't tell now what's the model), but this also happened with many other models (thomson, linksys, etc). The ideal solution was to put the router doing the DNS again. I don't have no problem in inserting public dns or other, but I liked to avoid that because in this case if a guest enters the house (not mine), he/she needs to insert the DNS, and most of them don't know how to do that. Link to comment Share on other sites More sharing options...
jesseinsf Posted February 20, 2012 Share Posted February 20, 2012 I had the same thing happen to my router and modem. My previous router did not have a feature that is required for Macs to run properly and would end up locking the router. It didn't have a "long preamble/short preamble" setting. Apple uses a "long preamble" setting where as Windows PCs adapt. My new router has this setting but has a new problem which would lock up the connection. The router would lock up when my HP printer would connect wirelessly to the router and with computers that uses Apple's mDNS protocol. This protocol is part of Apple's Bonjour service. So, if you have iTunes installed then that can be the problem. I got a beta firmware from netgear and this issue went away. As for my Cable Modem, I found out that my SB6120 modem did not meet all of Comcast's tests. So to fix this I bought a SB6121 modem that meets all of comcast's tests.My old modem (SB6120) would lock up every time someone on the network would use a P2P application. One housemate was downloading patch updates for "World of "warcraft" which uses P2P to download as the default (That would lock up the Modem). So this was my findings and if anyone else has anything to add to this then please do. :-) Link to comment Share on other sites More sharing options...
+BudMan MVC Posted February 20, 2012 MVC Share Posted February 20, 2012 What router do you have -- some can give different dns info vs just pointing to themselves -- others can not. Can your router run 3rd party, then for sure you would have the option. dd-wrt, tomato are examples of 3rd party router firmware. edit: "I found out that my SB6120 modem did not meet all of Comcast's tests. So to fix this I bought a SB6121 modem that meets all of comcast's tests.My old modem (SB6120) would lock up every time someone on the network would use a P2P application." I have a SB6120 -- and it has no problems running p2p! As to not meeting comcast tests, those are just PE tests.. Have nothing to do with the modem working correctly on that network. Unless the modem is stored in an oven or icebox those certs don't mean much ;) Link to comment Share on other sites More sharing options...
jesseinsf Posted February 20, 2012 Share Posted February 20, 2012 What router do you have -- some can give different dns info vs just pointing to themselves -- others can not. Can your router run 3rd party, then for sure you would have the option. dd-wrt, tomato are examples of 3rd party router firmware. edit: "I found out that my SB6120 modem did not meet all of Comcast's tests. So to fix this I bought a SB6121 modem that meets all of comcast's tests.My old modem (SB6120) would lock up every time someone on the network would use a P2P application." I have a SB6120 -- and it has no problems running p2p! As to not meeting comcast tests, those are just PE tests.. Have nothing to do with the modem working correctly on that network. Unless the modem is stored in an oven or icebox those certs don't mean much ;) The key word is performance. Directly wired to the router had no issues with my modem. It was wireless connections that would freeze the blinking light on the Modem. Most people have various versions of wireless N adapters which most are "Draft" versions of wireless N. I can't say that the wireless technology has something to do with this but it can be something to look in to. Link to comment Share on other sites More sharing options...
+BudMan MVC Posted February 20, 2012 MVC Share Posted February 20, 2012 What? :blink: You lost me completely.. Where did he say his modem locked up in the first place. My comment was to your nonsense about the sb6120 not being able to do p2p, and those PE tests are meaningless. The device is certified by UL and FCC, this is the only thing that matters! Link to comment Share on other sites More sharing options...
jesseinsf Posted February 20, 2012 Share Posted February 20, 2012 "Sometimes I see this happening: the Modem / Router is working OK with all the computers, but somewhere in time the Internet just stops working with one or many or all of the computers". Dude, I don't need to argue with your ignorance. The only thing he can do is download the latest firmware for his router and update all his network drivers. Btw, I added the Modem to my experience and not his. My response that confused you was addressing your claim that there is nothing wrong with the SB6120 Modem while using P2P. My problem was a performance issue where the modem locked up, so taken from your "Copy and Paste" from the Comcast site I highlighted the word "Performance". I should have also added the word "Network Impairments". Last thing which is somewhat unrelated, from the picture it seems you are using Windows XP..... we are all using Windows Vista/7 and the latest (or somewhat latest) OSX. Windows Vista/7 and OSX use more advanced networking technologies Which some routers may need a firmware update to work more efficiently. Modem issues are usually ISP compatibility related or just a defective modem. Link to comment Share on other sites More sharing options...
jesseinsf Posted February 20, 2012 Share Posted February 20, 2012 In the case of the 2 macs, it's a netgear (can't tell now what's the model), but this also happened with many other models (thomson, linksys, etc). The ideal solution was to put the router doing the DNS again. I don't have no problem in inserting public dns or other, but I liked to avoid that because in this case if a guest enters the house (not mine), he/she needs to insert the DNS, and most of them don't know how to do that. What netgear do you have? I have a WNDR4500 Netgear Router. Netgear gave me Beta firmware that fixed my issues. My original issue was a DNS issue. Link to comment Share on other sites More sharing options...
+BudMan MVC Posted February 21, 2012 MVC Share Posted February 21, 2012 "t seems you are using Windows XP" And you think that I only have 1 machine? Yes I was posting that from my work machine..Yes its xp -- just like your bs about the sb6120 -- wtf does that have to do with the users issue? Link to comment Share on other sites More sharing options...
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