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Martin Hope
Champ
Asked: 2016-05-08 08:30:32 +0800 CST
  • 0

My ubuntu system is connected to wireless network and I can access internet. I can ping 8.8.8.8 or google.com but I can't ping another Ubuntu system on the same wireless network. I tried ping, ssh, nmap, tracepath all failed. Please suggest what I can do to resolve this issue.

rob@yasu:~$ nmap -sn 10.0.0.0/24

Starting Nmap 7.01 ( https://nmap.org ) at 2016-05-07 12:21 EDT

Nmap scan report for 10.0.0.1

Host is up (0.0010s latency).

Nmap scan report for 10.0.0.9

Host is up (0.000033s latency).

Nmap done: 256 IP addresses (2 hosts up) scanned in 15.40 seconds

rob@yasu:~$ tracepath 10.0.0.9

1: 10.0.0.9 0.123ms reached

 Resume: pmtu 65535 hops 1 back 1

rob@yasu:~$ tracepath 10.0.0.1

1?: [LOCALHOST] pmtu 1500

1: 10.0.0.1 1.440ms reached

1: 10.0.0.1 5.162ms reached

 Resume: pmtu 1500 hops 1 back 1

rob@yasu:~$ tracepath 10.0.0.4

1?: [LOCALHOST] pmtu 1500

1: 10.0.0.9 785.561ms !H

1: 10.0.0.9 2890.676ms !H

 Resume: pmtu 1500

rob@yasu:~$ ping 10.0.0.1

PING 10.0.0.1 (10.0.0.1) 56(84) bytes of data.

64 bytes from 10.0.0.1: icmp_seq=1 ttl=64 time=4.28 ms

64 bytes from 10.0.0.1: icmp_seq=2 ttl=64 time=1.12 ms

^C

--- 10.0.0.1 ping statistics ---

2 packets transmitted, 2 received, 0% packet loss, time 999ms

rtt min/avg/max/mdev = 1.121/2.704/4.287/1.583 ms

rob@yasu:~$ ping 10.0.0.9

PING 10.0.0.9 (10.0.0.9) 56(84) bytes of data.

64 bytes from 10.0.0.9: icmp_seq=1 ttl=64 time=0.038 ms

64 bytes from 10.0.0.9: icmp_seq=2 ttl=64 time=0.066 ms

^C

--- 10.0.0.9 ping statistics ---

2 packets transmitted, 2 received, 0% packet loss, time 999ms

rtt min/avg/max/mdev = 0.038/0.052/0.066/0.014 ms

rob@yasu:~$ ping 10.0.0.4

PING 10.0.0.4 (10.0.0.4) 56(84) bytes of data.

From 10.0.0.9 icmp_seq=1 Destination Host Unreachable

From 10.0.0.9 icmp_seq=2 Destination Host Unreachable

^C

--- 10.0.0.4 ping statistics ---

3 packets transmitted, 0 received, +2 errors, 100% packet loss, time 1999ms

pipe 2

14.04
Martin Hope
Champ
Asked: 2016-01-13 12:39:16 +0800 CST
  • 2

I accidently removed all kernels from my Ubuntu 14.04 Trusty. I followed steps in this question's answers to install a new kernel but when I try to boot I don't see the 'Linux/ubuntu' option in my grub menu list. It only shows 'System Settings'.

How do I regenerate the earlier/default menu entries for ubuntu in grub?

Note:

  1. I am currently able to boot with these steps on grub prompt:

    set root=(lvm/ubuntu--vg-root)
linux /boot/vmlinuz-3.13.0-74-generic root=/dev/mapper/ubuntu--vg-root
initrd /boot/initrd.img-3.13.0-74-generic

    boot

  2. When on live usb, I copied vmlinuz, init... etc. from my boot partition to /boot folder because I could not find a way to use a separate boot partition from grub prompt.

14.04
Martin Hope
Champ
Asked: 2015-09-23 07:10:55 +0800 CST
  • 6

The wireless network on my dell laptop goes away many a times when resuming from 'suspend'. Once I run 'sudo service network-manager restart', it starts to work.

I was wondering if there was a way where I could restart the network while resuming from suspend and only if the wireless network was not up! What would be the best way to be able to restart network without having to enter a password?

I don't want to manually do it by going over to network icon and then taking some mouse actions. I did rather have a command which I could set up as a shortcut. I tried creating a bash executable with content 'service network-manager restart' and setting setuid on the executable as well as giving root the ownership of it but that didn't work.

I have Ubuntu 14.04 Trusty OS.

network-manager