I've been facing this problem with installing some other packages too. Inside terminal I type:

sudo apt-get install mysql-server

and I get the following:

Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following extra packages will be installed:
  libhtml-template-perl mysql-server-5.1 mysql-server-core-5.1
Suggested packages:
  libipc-sharedcache-perl tinyca mailx
The following NEW packages will be installed:
  libhtml-template-perl mysql-server mysql-server-5.1 mysql-server-core-5.1
0 upgraded, 4 newly installed, 0 to remove and 0 not upgraded.
Need to get 6,260 kB/11.0 MB of archives.
After this operation, 25.8 MB of additional disk space will be used.
Do you want to continue [Y/n]? Y
Err http://ubuntu.oss.eznetsols.org/ubuntu/ oneiric-updates/main mysql-server-5.1 i386 5.1.63-0ubuntu0.11.10.1
  Connection failed
Err http://ubuntu.oss.eznetsols.org/ubuntu/ oneiric-security/main mysql-server-5.1 i386 5.1.63-0ubuntu0.11.10.1
  Connection failed
Failed to fetch http://ubuntu.oss.eznetsols.org/ubuntu/pool/main/m/mysql-5.1/mysql-server-5.1_5.1.63-0ubuntu0.11.10.1_i386.deb  Connection failed
E: Unable to fetch some archives, maybe run apt-get update or try with --fix-missing?

On trying to install with synaptic package manager, I get the following screenshot I am bascially trying to setup LAMP. Any help/suggestion would be great. Thanks.