ns2 installation

Simply run this command in a Terminal to install ns2:

sudo apt-get update && sudo apt-get install ns2

If that does not work, please send us the output of these commands:

cat /etc/lsb-release

find /etc/apt -name '*.list' -exec bash -c 'echo -e "\n$1\n"; cat -n "$1"' _ '{}' \;

Hey Mark,
now i have installed ns-allinone-2.34 by following commands.
cd /root/ns-allinone-2.34
./install

again the same problem occurs.
when i type ns it shows % symbol but when i type nam "segmentation fault(core dumped)"

Outputs of commands u mentioned are:
cat /etc/lsb-release
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=14.04
DISTRIB_CODENAME=trusty
DISTRIB_DESCRIPTION="Ubuntu 14.04.1 LTS"

find /etc/apt -name '*.list' -exec bash -c 'echo -e "\n$1\n"; cat -n "$1"' _ '{}' \;

/etc/apt/sources.list

     1 # deb cdrom:[Ubuntu 12.04.2 LTS _Precise Pangolin_ - Release i386 (20130213)]/ precise main restricted
     2
     3 # See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
     4 # newer versions of the distribution.
     5 deb http://in.archive.ubuntu.com/ubuntu/ trusty main restricted
     6 deb-src http://in.archive.ubuntu.com/ubuntu/ trusty main restricted
     7
     8 ## Major bug fix updates produced after the final release of the
     9 ## distribution.
    10 deb http://in.archive.ubuntu.com/ubuntu/ trusty-updates main restricted
    11 deb-src http://in.archive.ubuntu.com/ubuntu/ trusty-updates main restricted
    12
    13 ## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
    14 ## team. Also, please note that software in universe WILL NOT receive any
    15 ## review or updates from the Ubuntu security team.
    16 deb http://in.archive.ubuntu.com/ubuntu/ trusty universe
    17 deb-src http://in.archive.ubuntu.com/ubuntu/ trusty universe
    18 deb http://in.archive.ubuntu.com/ubuntu/ trusty-updates universe
    19 deb-src http://in.archive.ubuntu.com/ubuntu/ trusty-updates universe
    20
    21 ## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
    22 ## team, and may not be under a free licence. Please satisfy yourself as to
    23 ## your rights to use the software. Also, please note that software in
    24 ## multiverse WILL NOT receive any review or updates from the Ubuntu
    25 ## security team.
    26 deb http://in.archive.ubuntu.com/ubuntu/ trusty multiverse
    27 deb-src http://in.archive.ubuntu.com/ubuntu/ trusty multiverse
    28 deb http://in.archive.ubuntu.com/ubuntu/ trusty-updates multiverse
    29 deb-src http://in.archive.ubuntu.com/ubuntu/ trusty-updates multiverse
    30
    31 ## N.B. software from this repository may not have been tested as
    32 ## extensively as that contained in the main release, although it includes
    33 ## newer versions of some applications which may provide useful features.
    34 ## Also, please note that software in backports WILL NOT receive any review
    35 ## or updates from the Ubuntu security team.
    36 deb http://in.archive.ubuntu.com/ubuntu/ trusty-backports main restricted universe multiverse
    37 deb-src http://in.archive.ubuntu.com/ubuntu/ trusty-backports main restricted universe multiverse
    38
    39 deb http://security.ubuntu.com/ubuntu trusty-security main restricted
    40 deb-src http://security.ubuntu.com/ubuntu trusty-security main restricted
    41 deb http://security.ubuntu.com/ubuntu trusty-security universe
    42 deb-src http://security.ubuntu.com/ubuntu trusty-security universe
    43 deb http://security.ubuntu.com/ubuntu trusty-security multiverse
    44 deb-src http://security.ubuntu.com/ubuntu trusty-security multiverse
    45
    46 ## Uncomment the following two lines to add software from Canonical's
    47 ## 'partner' repository.
    48 ## This software is not part of Ubuntu, but is offered by Canonical and the
    49 ## respective vendors as a service to Ubuntu users.
    50 deb http://archive.canonical.com/ubuntu precise partner
    51 # deb-src http://archive.canonical.com/ubuntu precise partner
    52
    53 ## This software is not part of Ubuntu, but is offered by third-party
    54 ## developers who want to ship their latest software.
    55 deb http://extras.ubuntu.com/ubuntu trusty main
    56 deb http://in.archive.ubuntu.com/ubuntu/ trusty-proposed restricted universe main multiverse
    57 deb-src http://extras.ubuntu.com/ubuntu trusty main

Why are you manually installing ns-allinone-2.34 if there is a pre-compiled 2.35 version available in the standard Ubuntu repositories? The command given by Mark Rijckenberg should install the standard Ubuntu version, and there are much better chances that this version works well than the one you install manually.
(By the way, there would also be an updated ns-allinone-2.35 version available.)

There is a nam Ubuntu package as well:

http://packages.ubuntu.com/search?suite=trusty&section=all&arch=any&keywords=nam&searchon=all

So run these Terminal commands:

sudo apt-get update

sudo apt-get install ns2

sudo apt-get install nam

sudo apt-get install gns3

So you can also get a graphical network simulator:

http://packages.ubuntu.com/trusty/gns3

Do not ignore my instructions this time, please.....