No IP address via DHCP

You need to connect your RPi to a TV before you can SSH into it. 

You need to do a first configuration via raspi-config

This will come up on boot.

No, it is the modem/switch.

What confused me, that I tried to boot PI connecting it directly to the cable modem and it did not get any IP. I forgot that the IP given before to my laptop, is kept for a while and new IP was obviously not given.

Power cycle of the cable modem and connecting a PI directly to it or via switch, solved the problem, it got IP. Laptop connected after this, did not get an IP...

So in reality it is a problem of the cable modem/switch – only one IP via DHCP.

I have used this switch with several PC those had static IPs and is surprised it does not work with DHCP.

I have a monitor connected to PI.

One can change raspi-config or /etc/network/interfaces and reboot. The same effect.

Usually, the range of dhcp ip adresses in a router is adjustable. Maybe your modem/router only has one ip available for dhcp.

A solution could be to place a router behind the existing modem/router combination and connecting your devices to that.

Your laptop may not be configured to send internet connection to your raspberry pi.

I will try to find how to increase the number of IP addresses in this modem.

One can place a router behind it but one needs to have it first.

Why a laptop should not be able to send internet connection to PI?

It can connect via SSH to any host that allows it. Host (PI, in this case), not laptop.

No, the problem is I saw that PI did not get an IP address at all.

I think the case is now clear - I need to increase number of IP addresses in the modem.

Hi Oleg,

Your problem seems very similar to the one here on the RasPi forum: http://www.raspberrypi.org/phpBB3/viewtopic.php?f=28&t=15739

It would appear in both cases this is a hardware problem - a faulty Pi.

I'll be honest and say in all the time I have been messing around with (small)  networks, a lack of available IP addresses via DHCP has never happened to me. Do you have an opportunity to borrow another Raspi and try with your SD card etc ?

Steve

Hi Steve,

I actually have two Pi's and tried both. The same problem.

One needs to to try increasing the range of IP addresses of the cable modem. Hope it is possible.

I do not remember it was anywere written when I made a contract for Internet connection.

Regards.

Dear Oleg:

If it were me, I would try this.

1. Write down the ipaddress, netmask, gateway and dns servers (there should be two) given to your laptop and disconnect the laptop.

2. Using ifconfig, set the Pi to the same address that was assigned to the laptop and command it to be up.

  ifconfig eth0 192.168.x.y netmask 255.255.255.0 up

3. Ping the gateway, which if you have a home network similar to many will be something like 192.168.1.1 or 192.168.1.254

If this works, then you know the Pi works and the issue is with the home network. If this doesnt work, then more diagnosis of the Pi is indicated.

In California, usually when one subscribes to cable service with a cable modem, one gets 5 DHCP addresses as a default. I would consider it unusual to have only one.

Charles

The problem you are seeing is in the modem or the way the ISP handles DHCP. I have a Time Warner Cable modem (Motorola SB5100 SurfBoard)

that makes me do the same power cycle thing whenever I change which computer it is connected to: Rasperry Pi, one of several PCs, or laptop.

I'm not sure about needing to get another a IP address to fix it. It might be tied to the MAC address as a way to prevent multiple computers using

the same modem through a simple non-managed Ethernet switch to "encourage " you to rent a router or a modem with a router from the ISP.

From your decription, you have a cable modem *not* a gateway/router.  For multiple devices to be connected at the same time, you need to have a gateway or router to nat one of the private networks (10.x.x.x/192.168.x.x/172.16.x.x) to the public address you get from the cable modem.  Sometimes the modem/router is combined into a single device.  Provide (or google) the model number of your cable modem to find out if it is a gateway/router or modem.  The most common private range used is 192.168.1.x or in CIDR format 192.168.1.0/24.  It is also possible that you have a gateway but it's configured to only serve up one IP address.  This is sometimes done by providers as a security feature.  If this is the case and you have access to the configuration ui of the cable router, then you should see if the lan dhcp configuration has a limit of number of addresses set to 1.  Good luck.