libc-ares2 software package provides library for asyncronous name resolves, you can install in your Ubuntu 12.04 LTS (Precise Pangolin) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install libc-ares2
libc-ares2 is installed in your system.
Make ensure the libc-ares2 package were installed using the commands given below,
$ sudo dpkg-query -l | grep libc-ares2 *
You will get with libc-ares2 package name, version, architecture and description in a table
| Distro | Ubuntu 12 04 lts precise pangolin |
| Section | Libraries |
| Package | libc-ares2 |
| Version | 1.7.5-1 |
| Description | library for asyncronous name resolves |
| Sub Section | libs |