Description of problem:

dhcp6c client daemon doesn't stopped if DHCPV6C_OPTIONS undefined in ifcfg-eth0 config file during ifdown eth0 command.

There is the BUG in ifup-eth network script:

---
dhcp6_pid=(`/bin/ps -eo 'pid,args' | /bin/grep "dhcp6c ${DHCPV6C_OPTIONS} ${DEVICE}" | egrep -v grep`)
---

So, if DHCPV6C_OPTIONS is undefined there are double space and grep doesn't work, pid is undefined.

Version-Release number of selected component (if applicable):

initscripts-8.45.30-3.el5_5.1

How reproducible:

100%

Steps to Reproduce:
1. Setup the DHCP client for IPv6
2. ifup eth0; ifdown eth0
3. See that dhcp6c daemon was not stopped
  
Actual results:

dhcp6c daemon doesn't stopped when interface is ifdown'ed

Expected results:

dhcp6c daemon should be stopped when interface is ifdown'ed