I will clean ns2.35 from ubuntu15.04, I command follow run but this message created:
mada@ubuntu:~$ sudo apt-get remove ns2
Reading package lists... Done
Building dependency tree
Reading state information... Done
Package 'ns2' is not installed, so not removed
0 upgraded, 0 newly installed, 0 to remove and 14 not upgraded.
ns235 from ubuntu does not remove, while I work with it, I install ns-allinone-2.35_gcc5.tar.gz in Ubuntu 15.04.
apt will know packages.deb installed with apt (apt-get), not any manually installed files.
Removing a folder ns-allinone-2.35/ :
cd [path-to-folder-with-ns-allinone-2.35]
rm -rf ns-allinone-2.35/
If any ns2 executable´s in /usr/local/bin/: Must also be deleted manually.