Internet access to Ethernet Shield

Greetings all! I know this subject has been beat to death a few times, but this newbee needs a little help.

My Web Server example works just fine on my LAN using the UNO and my Wiznet 5500 shield. However, when trying to access the Ethernet Shield from outside my network, I have no joy.

I have my router set up for port forwarding with the IP of my shield and the port number assigned and enabled. I have even tried disabling my firewall in the router. Still no joy. I have googled 'whats my IP'. From outside my network I have entered: http://XX.XXX.XXX.XX:222. I get no connection. I have tried numerous port numbers and still nothing.

It almost seems like my Linksys WRTU54G router is blocking incoming requests. Any ideas gents?

Thank you!

Get a new router?

Is your ISP a wireless carrier like T-Mobile or Verizon? They might be blocking external requests before they even get to your router.

I am using Comcast Cable internet. It is not a wireless carrier.

Yes, I have considered a new router. Seems like it should not be necessary however since it does have port forwarding. Frustrating problem!

Your provider may be blocking inbound requests from the internet long before the request gets to your router.

edit: Have you asked Comcast about your challenge?

What is your WRTU54G WAN ip ?

  • It's a external IP ( it's the same as the ip provided by "what's your IP search" ) ?
  • Or it more like 10.0.0.XXX , 192.168.xxx.xxx ?

Case 2, you need configure portforward in your comcat's modem to redirect the 222 port to the linksys WAN ipadress.

Yes, I will call Comcast. Maybe there is some configuration necessary in the modem. But I have not configured anything in the Motorola modem. I will check it.

As for my WAN IP it is of the form 50.135.xxx.38

The IP of my shield is 192.168.0.111. This is the IP that is port forwarded in the router using port 222.

My Gateway IP is 192.168.0.1

IPv4 is 192.168.0.100

I just looked at my Motorola cable modem at 192.168.100.0

There are many tabs of data, but nothing that can be configured or altered.

N6XB:
Yes, I will call Comcast.

Will be a useless venture. I have Comcast.

You will probably need a commercial account to get Comcast to route a public ip to your router.

Still no luck with this problem. Comcast says that since I own my own cable modem, they can do nothing. They said to talk to Motorola. They indicate port forwarding should be no problem.

There is no configuration menus for the SB6121 modem. 192.168.100.1 only shows modem configuration, but does not allow any changes. There is also no port forwarding information even on this screen.

I feel my router is port forwarding OK. Maybe the modem is blocking port forwarding, but I cannot be sure.

After talking with Comcast, in India, I am not any further along in solving this port forwarding issue.

I am not sure what to try next....:frowning:

My Gateway IP is 192.168.0.1

IPv4 is 192.168.0.100

Unless you have changed the router's localnet IP and the DHCP range, you must assign an IP from
192.168.100.2 to 192.168.100.10
or
192.168.100.43 to 192.168.100.254.

Read small print under "DHCP Server Enabled" on page 15 here:
http://surfboard.com/wp-content/uploads/2016/05/ARRIS_SURFboard_SB6121_User_Guide.pdf

If you are using a WRT54 router inline with the Motorola cablemodem, you must forward both routers.

edit: I don't see the capability to port forward in your cablemodem. You need a more advanced cablemodem, like the Motorola SBG6400.

N6XB:
Yes, I will call Comcast. Maybe there is some configuration necessary in the modem. But I have not configured anything in the Motorola modem. I will check it.

As for my WAN IP it is of the form 50.135.xxx.38

Correct me guys, if I'm wrong. So far as I could understand this motorola cable modem is acting a a bridge device.
So really don't need port-forwarding build in it, as the "external IP - WAN" is managed by the linksys wrt54.
Try to check again, maybe with a lower port number, or higher (like 3000,4000 ) for port-forward in the linksys.

norton check
or online:
NOIP advise

According to that model Motorola cablemodem user manual, it is using a 192.168.100.x localnet ip range on the LAN. You must get a more sophisticated Motorola cablemodem to get the port forwarding feature as I mentioned in reply #11.

SurferTim:
According to that model Motorola cablemodem user manual, it is using a 192.168.100.x localnet ip range on the LAN. You must get a more sophisticated Motorola cablemodem to get the port forwarding feature as I mentioned in reply #11.

I remember like this one, an "MOTOROLA 4100" used by a local internet provider in my country, some years ago... 192.168.100.1 is only for checking and initial setup, even is not register on the network operator. Soon you got sync by the coaxial cable from the internet provider, and connect a rj45 device ( could be your own computer or a router ) on it, the new attached device will get a external IP ( wan ) as the OP describe in post #6, the motorola will only act as bridge.

The cablemodem user manual states if you use DHCP, you will get a an IP somewhere from 192.168.100.11 to 192.168.100.42. How does it bridge with that?

SurferTim:
The cablemodem user manual states if you use DHCP, you will get a an IP somewhere from 192.168.100.11 to 192.168.100.42. How does it bridge with that?

Post #5

I asked to the OP to tell about the wan ip on the linksys.

Post #6
His answer: "As for my WAN IP it is of the form 50.135.xxx.38"

Not bridge mode ?

Remember, Internet provider have some time, custom firmware from the network device manufacturer, and user manual are only for reference.

There is no menu selection for port forwarding in that cablemodem. If the WAN IP is 50.135.xxx.38, then that would need to be port forwarded to a localnet IP. Normally if a device is in bridge mode, you will get a public IP with DHCP like my cablemodem provides.

SurferTim:
There is no menu selection for port forwarding in that cablemodem. If the WAN IP is 50.135.xxx.38, then that would need to be port forwarded to a localnet IP. Normally if a device is in bridge mode, you will get a public IP with DHCP like my cablemodem provides.

Like he get at his linksys. He get a public IP as wan IP, "50.135.XXX.38" from comcast.

He gets the public IP from whatsmyip.org, but that is not on his localnet. According to the user manual for the Motorola cablemodem, the cablemodem assigns his Linksys a 192.168.100.x ip, and the Linksys assigns his Arduino a 192.168.1.x ip if it is a "standard" Linksys router.

If this is not the case, then the Motorola user manual is incorrect.