Connected to the Internet, but can't ssh or ping

Question

I'm having a problem with my Raspberry Pi where I can't ssh into or even ping it, yet I'm using it on my TV, and it's clearly connected to the network/Internet.

I've used the attached keyboard to run several curl commands, wget, and apt-get update, and they all work fine, but I can't connect to it remotely using the IP address, and it won't respond to pings. I've just freshly installed Raspbian, and so far all I've done is set up Wi-Fi, which is clearly working.

Answer 1

This happens a lot with one of my Raspberry Pis. I have a script which checks for an Internet connection and runs ifup wlan0 when a connection is not present. Some of the things you could try:

• Rebooting the Raspberry Pi
• Checking that you have a valid IP address using ifconfig
• Ensuring that you have power-saving features disabled on the dongle by adding wireless-power off to your /etc/network/interfaces file
• Run ifup --force wlan0

Here's a script which runs every five minutes from cron:

#!/bin/bash
#Script to check the network connection

#Check network connection
if /sbin/ifconfig wlan0 | grep -q "inet addr:" ; then
    #Connection is good; do nothing
    echo "$(date "+%D [%H:%M:%S]") Connection is up"
else
    echo "$(date "+%D [%H:%M:%S]") Network connection down. Attempting to reconnect..."
    sudo /sbin/ifup --force wlan0
fi

If that is a wireless card power management issue, you can also have a look at WLAN disappears after some time.

Many wireless network cards don't support wireless-power off option in /etc/network/interfaces. To disable power management with a 8192CU module loaded, you can create a file sudo nano /etc/modprobe.d/8192cu.conf with the following contents.

# Disable power management
options 8192cu rtw_power_mgnt=0

Answer 2

I have found myself in this issue before. Sometimes my router would pick up the wrong IP address. To fix the issue I used nmap to find my Raspberry Pi. I think that the command was nmap 192.168.1.0/24.

That should be able to find the IP address and help you to ssh and ping. If you are connected by a monitor then run ifconfig inside the terminal application.

Answer 3

I was having similar problems. With an Ethernet connection I could remote desktop from my PC into the Raspberry Pi, but with Wi-Fi the connection failed; I couldn't even ping the Raspberry Pi.

It turned out to be a router problem. I created a new rule for routing port 3389 (used by RDP) to the IP address of the Raspberry Pi (I also setup the router to assign the same IP address to the MAC address of the Raspberry Pi Wi-Fi). This resolved the problem. Ping still fails sometimes; I suspect that is more related to the power management solution mentioned above.

I found the instructions for my NetGear router setup in Port Forwarding the Netgear WGT624v3 Router for Remote Desktop.

Answer 4

try using raspi-config and enable ssh from interface option.