I try to get update on my Ubuntu 15.04 but if failed to connect to server

me@me:~$ sudo apt-get update 
Err http://archive.ubuntu.com vivid InRelease
Err http://archive.ubuntu.com vivid-updates InRelease
Err http://archive.ubuntu.com vivid-backports InRelease
Err http://archive.ubuntu.com vivid-security InRelease
Err http://archive.ubuntu.com vivid Release.gpg
  Unable to connect to
Err http://archive.ubuntu.com vivid-updates Release.gpg
  Unable to connect to
Err http://archive.ubuntu.com vivid-backports Release.gpg
  Unable to connect to
Err http://archive.ubuntu.com vivid-security Release.gpg
  Unable to connect to
Reading package lists... Done
W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/vivid/InRelease  
W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/vivid-updates/InRelease  
W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/vivid-backports/InRelease  
W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/vivid-security/InRelease  
W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/vivid/Release.gpg  Unable to connect to
W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/vivid-updates/Release.gpg  Unable to connect to
W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/vivid-backports/Release.gpg  Unable to connect to
W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/vivid-security/Release.gpg  Unable to connect to
W: Some index files failed to download. They have been ignored, or old ones used instead

I tried to find solutions but cannot fix it. Here what I tried so far:

  1. Modify in /etc/resolv.conf to:

  2. I tried to ping Ubuntu server

    me@me:~$ ping archive.ubuntu.com
    PING archive.ubuntu.com ( 56(84) bytes of data.
    64 bytes from likho.canonical.com ( icmp_seq=1 ttl=41 time=259 ms
    64 bytes from likho.canonical.com ( icmp_seq=2 ttl=41 time=257 ms
    64 bytes from likho.canonical.com ( icmp_seq=3 ttl=41 time=255 ms
    64 bytes from likho.canonical.com ( icmp_seq=4 ttl=41 time=288 ms
    --- archive.ubuntu.com ping statistics ---
    4 packets transmitted, 4 received, 0% packet loss, time 3003ms
    rtt min/avg/max/mdev = 255.160/265.270/288.347/13.437 ms
  3. In Software & Update, change server to Main Server

  4. In /etc/apt/apt.conf I found this line:


    I tried to add # in front of it and didn't work. Then try to connect to and nothing happens. And ping to this address:

    me@me:~$ sudo ping
    PING ( 56(84) bytes of data.
    --- ping statistics ---
    16 packets transmitted, 0 received, 100% packet loss, time 14999ms

It seems related to proxy or firewall but I don't use any of them. Does anybody know how to fix this?

  • Edit your question and add the output of cat /etc/apt/apt.conf
    – A.B.
    Oct 16, 2015 at 7:52
  • The output of it was added, I'm new to this forum so I'm not format code well to make it easy.
    – Fingertron
    Oct 16, 2015 at 12:36
  • 1
    Try this echo | sudo tee /etc/apt/apt.conf; sudo apt-get update
    – A.B.
    Oct 16, 2015 at 12:47
  • @A.B. Thank you, that worked for me. I am a Linux novice, and an expert customer tinkered with this computer, so I could no longer download anything from any repo. Your solution worked for me.
    – DrOnline
    Aug 14, 2020 at 8:12

2 Answers 2


My problem was solved. I don't know what makes it works again. I tried these command unset http_proxy and unset https_proxy as @nilesh_101 suggested. One more thing I did is change proxy and then change it to default again. Thanks all you guys for answering my question!


I had the same problem.Then i clear all the contents of apt.conf file and it works perfectly.

  • The content was cleared, but it don't work.
    – Fingertron
    Oct 16, 2015 at 13:25
  • please post what is the output for this command " env | grep -i proxy "
    – nilesh_101
    Oct 16, 2015 at 13:27
  • Try this 1. unset http_proxy 2. unset https_proxy
    – nilesh_101
    Oct 16, 2015 at 13:31
  • The output of the env | grep -i proxy is http_proxy= . What is that?
    – Fingertron
    Oct 16, 2015 at 13:34
  • Did you try unset commands ? Which i hav posted above .
    – nilesh_101
    Oct 16, 2015 at 13:35

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