i got error when i am trying to install L2TP .. can any help me ..solve this issuse

root@t-Aspire-5742:/# sudo ipsec verify

Checking your system to see if IPsec got installed and started correctly:
Version check and ipsec on-path                                 [OK]

Linux Openswan U2.6.37/K3.5.0-42-generic (netkey)
Checking for IPsec support in kernel                            [OK]

 SAref kernel support                                           [N/A]

 NETKEY:  Testing XFRM related proc values                      [FAILED]

  Please disable /proc/sys/net/ipv4/conf/*/send_redirects
  or NETKEY will cause the sending of bogus ICMP redirects! [FAILED]

  Please disable /proc/sys/net/ipv4/conf/*/accept_redirects
  or NETKEY will accept bogus ICMP redirects                    [OK]

Checking that pluto is running                                  [OK]

 Pluto listening for IKE on udp 500                             [OK]

 Pluto listening for NAT-T on udp 4500                          [OK]

Two or more interfaces found, checking IP forwarding            [FAILED]

Checking for 'ip' command                                       [OK]

Checking /bin/sh is not /bin/dash                               [WARNING]

Checking for 'iptables' command                                 [OK]

Opportunistic Encryption Support                                [DISABLED]

You need to disable send and accept:

# Disable send redirects
echo 0 > /proc/sys/net/ipv4/conf/all/send_redirects
echo 0 > /proc/sys/net/ipv4/conf/default/send_redirects
echo 0 > /proc/sys/net/ipv4/conf/eth0/send_redirects
echo 0 > /proc/sys/net/ipv4/conf/lo/send_redirects

# Disable accept redirects
echo 0 > /proc/sys/net/ipv4/conf/all/accept_redirects
echo 0 > /proc/sys/net/ipv4/conf/default/accept_redirects
echo 0 > /proc/sys/net/ipv4/conf/eth0/accept_redirects
echo 0 > /proc/sys/net/ipv4/conf/lo/accept_redirects

To make it permanent on reboot, in your sysctl.conf place the below lines

net.ipv4.conf.all.accept_redirects = 0 
net.ipv4.conf.all.send_redirects = 0
net.ipv4.conf.eth0.accept_redirects = 0 
net.ipv4.conf.eth0.send_redirects = 0
net.ipv4.conf.default.accept_redirects = 0 
net.ipv4.conf.default.send_redirects = 0
net.ipv4.conf.lo.accept_redirects = 0 
net.ipv4.conf.lo.send_redirects = 0