error: permission denied on key

[ÜmitAtay]

Hello,

centos5 new exchange server I'm getting some errors.
eg I want the server to ping requests but fails to close;

root @ centostr [~] # /sbin/sysctl-p
error: permission denied on key 'net.ipv4.icmp_echo_ignore_all'
root @ centostr [~] #

PROXMOX Information;
proxmox1:~# uname -a
Linux proxmox1 2.6.24-7-pve #1 SMP PREEMPT Tue Jun 2 08:00:29 CEST 2009 x86_64 GNU/Linux
proxmox1:~#

or

proxmox1:~# pveversion -v
pve-manager: 1.3-1 (pve-manager/1.3/4023)
qemu-server: 1.0-14
pve-kernel: 2.6.24-8
pve-kvm: 86-1
pve-firmware: 1
vncterm: 0.9-2
vzctl: 3.0.23-1pve3
vzdump: 1.1-2
vzprocps: 2.0.11-1dso2
vzquota: 3.0.11-1
proxmox1:~#

or

proxmox1:~# sysctl -p
net.ipv4.tcp_syncookies = 1
net.ipv4.ip_forward = 0
net.ipv4.conf.default.forwarding = 1
net.ipv4.conf.default.proxy_arp = 0
net.ipv4.conf.all.rp_filter = 1
kernel.sysrq = 1
net.ipv4.conf.default.send_redirects = 1
net.ipv4.conf.all.send_redirects = 0
proxmox1:~#


How can I fix this? Thanks for the help.