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



Question:

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]  


Solution:1

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  


Solution:2

Please norice the /proc/sys/net/ipv4/conf/... files are read only even for root user. You should disable it using your VPN configuration. For example in OpenSwan you should do:

Prompt> sudo vi /etc/sysctl.conf  net.ipv4.conf.all.accept_redirects = 0  net.ipv4.conf.all.send_redirects = 0  

You can also use

sudo sysctl stuff.you.want.to.change=newValue  

As suggested by comments to avoid reboot


Note:If u also have question or solution just comment us below or mail us on toontricks1994@gmail.com
Previous
Next Post »