Really Simple ? : No router, change DNS svr, fail. Why?

zapp22 · 10 Sep 2019

I am not well trained in internet architecture. I made a simple change that should have "just worked" but instead resulted in no service to the Internet, which I imagine was caused by inability to reach the DNS servers I specified. Here's detail:
- Couldn't be simpler: in a home, the users have Spectrum as ISP, and a single lone Cable Modem. There is one desktop running windows 7 connected by Ethernet cable. All working well.
- Due to some iterative lag in internet response, I wondered changing to specific DNS server config at the workstation would help speed any.
- opened the NIC Properties and accessed the IPv4 settings, from Obtain-Automatically to "Use the following" and punched in the Google DNS server addresses. I triple checked my syntax, ticked the 'verify' box and backed out. The servers checked out ok.
- but there was no Internet access at all.

- I rebooted. Still nothing.

What I did not do was power off the Cable Modem to get a new lease. Would that have resolved the issue?

pls explain why this was a problemo

thx
z

samuria · 10 Sep 2019

OPen a cmd prompt type

ipconfig /all

post results

zapp22 · 10 Sep 2019

i'm not at the pc; i changed it back to auto when it failed to connect.

file3456 · 11 Sep 2019

It may be due to the fact your modem is using its own DNS servers and so being your custom entered DNS servers in Windows is conflicting with the router. Yes, perhaps a reboot of your modem may have rectified the issue.

The other problem may be that your modem limits port 53 (The DNS port) and if it's messing around with that port, your custom DNS entries entered into Windows will be null and void.

If you use a modem directly connected to your computer/s, you will want to make sure that at least your Windows firewall is turned on or use a third-party firewall like the free version from Comodo. It's been years since I used their firewall, but last I used it, it was pretty decent. Though, it can be kinda complicated.

Another thing to really consider is a router that you can use with your modem that will offer better security since routers by default use SPI (Stateful Packet Inspection) which is a form of firewall in its self. I'd also roll with a third-party firmware to help avoid router compromise from hackers. Two great third-party router firmware packages are ASUS Merlin and DD-WRT. Typically you'd install these two different firmware packages yourself in a compatible router, but if you go to eBay and just search for ASUS Merlin or DD-WRT, you can find a router with it already installed. Just don't buy a very old Linksys router with DD-WRT installed. I've seen quite a bit of those on eBay and you don't want that as they are very old and slow.

Moving forward, you may be interested in OpenDNS instead of just using Google's 8.8.8.8 DNS server's. OpenDNS can provide some more security and if you have kids can block porn and what not. OpenDNS also has a nice feature in where if the website's DNS isn't working, OpenDNS will use a cached version (I think it is) and still fetch the website. You can use OpenDNS' DNS IPs free without an account, or you can create and account for more features like the aforementioned content blocking. Some router firmware also offers this feature. I know ASUS Merlin does. But a sure fire catch all is OpenDNS which uses Saint Bernard for content blocking. The one thing about using OpenDNS is that you need to update your IP address if it changes in your OpenDNS account. That can be done automatically with their auto update client that runs in the task bar and will automatically update your IP address at OpenDNS should it ever change. Home Internet Security | OpenDNS

On the subject of routers. If you use one with your modem, your modem will more than likely need to be set in bridging mode. Consult your user manual or ISP website on how to access the internal features of your modem to do that. Typically you type an internal private IP address in your address bar to gain access. It may be something like 10.0.0.1 or 192.168.1.1. This website can help. The other things you need to do is make sure port forwarding is off, UPnP is off and the default username and password are changed in a router or modem. Failing to do those simple tasks can open the door for a hacker to turn your router or modem into a botnet/zombie and so this allows the hacker to use your IP address as a sort of base of operations to hack other computers/servers, send spam, etc all from your IP address. I have in fact seen my fair share of infected routers try and do nasty things at my website.

Anyway, longer post then what I was planning, but it's all part in parcel of the subject at hand.

file3456 · 11 Sep 2019

As to your issue of lag on the Internet, is your ISP a DSL provider? If so, it could be due to the distance from the DSLAM in your area, ingress on your phone line, old telephone line or just interference in the phone line its self. You can go to broadbandreports.com and they have some tools that can help diagnose connection issues. One such tool is Smokeping. This tool will send constant pings to your modem for 24 hours. Once done you can look at its ping response graph and see if you have high spikes. If you do, chances are there is something between you and the Broadbandreports.com website that is causing the lag. It could be the phone line or ingress in the line. To use Smokeping you need to allow ICMP ping requests in your modem. So you need to log into the modem to turn that setting on to allow pings. Once done with Smokeping you should turn it back off.

Now I'm assuming it's your line that's causing Internet lag. You could also have something going on in the computer. Is there lots of stuff in the taskbar, etc?

Try flushing your DNS and resetting the TCP/IP stack.

The Nuclear Option: Resetting The Crap Out Of Your Network Adapters in Vista - Scott Hanselman