[SOLVED] Static Ip issue

Jan 29, 2022
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Hi,

I had a static ip issue lately.

My setup is modem (from isp) to router (tp link archer c6 model) to switch with several devices connected to the switch. All modem lights are good but there is no internet

I tried to bypass the router and set up the static ip address, gateway and dns directly on my laptop and it still did not work (lan 1 from modem to lan port on my laptop). I am told that the modem is setup as a bridge connection

As they ISP has been slow in providing a response (its almost been a week), I decided to do some checking on my own. I was able to successfully ping the gateway but I could not ping the static ip they provided. Could this possibly a damaged fiber cord issue on my side or is it a problem on their side.
 
Solution
So you put the public IP on your pc or router and then you can ping the gateway IP.

That means you have communication with the ISP. Where are you trying to ping the public IP from. I mean when it is set on your pc it should ping itself. A router is a little more tricky and many times you can't access the WAN ip from the LAN.

Now there are all kinds of things that can prevent say some server on the internet from talking to your public IP. What is very strange is that you are saying you have no internet.

I mean this is the simplest configuration. Lets say you instead tried to ping 8.8.8.8. Your pc would build a packet with the destination IP of 8.8.8.8 and a source IP of "your public ip". It would then put the...
Hi,

Yes the cable is good. I have a lan cable tester at home it tested good and I also tried a different cable. What does it mean if the gateway can be pingged but the static ip cannot? The modem is a Huawei EG8145V5
 
Maybe describe more how you are setting up the static IP.

What is not clear on what you mean you ping the "gateway". Something on your LAN or the gateway IP on the WAN port. When you are manually configuring a static IP you must have the subnet mask and gateway correct. The ISP should have given you that info along with the static IP.

Now if you are running something like PPPoE then it is done a bit different.
 
I pingged the default gateway provided by the isp. All the config provided by the isp has been configured properly (i.e. static ip, subnet mask, default gateway, primary and secondary dns). The gateway I am trying to ping is the provided default gateway by the isp
 
So you put the public IP on your pc or router and then you can ping the gateway IP.

That means you have communication with the ISP. Where are you trying to ping the public IP from. I mean when it is set on your pc it should ping itself. A router is a little more tricky and many times you can't access the WAN ip from the LAN.

Now there are all kinds of things that can prevent say some server on the internet from talking to your public IP. What is very strange is that you are saying you have no internet.

I mean this is the simplest configuration. Lets say you instead tried to ping 8.8.8.8. Your pc would build a packet with the destination IP of 8.8.8.8 and a source IP of "your public ip". It would then put the mac address of the gateway in, it previously looked it up with a ARP, and send this packet to the ISP.
The only difference when you ping the gateway is it puts the IP of the gateway in the destination. This is really the only difference in the packets, it is still actually sending the data to the mac address of the gateway no matter what destination IP is in side the packet.

You can confirm this by loading wireshark on the machine and look at the packets.

This almost has to be a ISP problem if we assume that nothing blocks the sending of certain packets. Not likely since both the router and pc do it. So for some reason the ISP is getting the packet and then either it is send out and somehow the response is being dropped or the ISP never actually sends the packet out its router to the
next router in the chain. Maybe you get lucky and tracert 8.8.8.8 might show something.
 
Solution
Hi,

I had a static ip issue lately.

My setup is modem (from isp) to router (tp link archer c6 model) to switch with several devices connected to the switch. All modem lights are good but there is no internet

I tried to bypass the router and set up the static ip address, gateway and dns directly on my laptop and it still did not work (lan 1 from modem to lan port on my laptop). I am told that the modem is setup as a bridge connection

As they ISP has been slow in providing a response (its almost been a week), I decided to do some checking on my own. I was able to successfully ping the gateway but I could not ping the static ip they provided. Could this possibly a damaged fiber cord issue on my side or is it a problem on their side.

What is this static IP you are talking about configured on? Did they give you a public static IP for your modem? Or a static public IP for one of your computers to use as a server in a DMZ connection?

Static IP setup on your own private network does not matter one bit to the router/modem, all you are doing with it is just giving one of your systems a static internal IP. Only thing that can cause issues there is if you setup the IP incorrectly. Make sure all the network settings for the IPs you plugged in are correct for your network.