Why does nfs-common have unmet dependencies?

[Peng Yu]

Hi, I see the following problem when I try to install nfs-common. Does
anybody know what is wrong?

This server is an openldap server which is used by many other servers
for authentication purpose. I do not want to mess it up. Could anybody
let me know what is the safest way to proceed? Thanks.

$ cat /etc/issue
Ubuntu 14.04 LTS \n \l
$ sudo apt-get install nfs-common
Reading package lists... Done
Building dependency tree
Reading state information... Done
You might want to run 'apt-get -f install' to correct these:
The following packages have unmet dependencies:
 linux-headers-generic : Depends: linux-headers-3.13.0-34-generic but
it is not going to be installed
 nfs-common : Depends: libgssglue1 but it is not going to be installed
              Depends: libnfsidmap2 but it is not going to be installed
              Depends: libtirpc1 but it is not going to be installed
              Depends: rpcbind (>= 0.2.0-6ubuntu1) but it is not going
to be installed
E: Unmet dependencies. Try 'apt-get -f install' with no packages (or
specify a solution).

-- 
Regards,
Peng