[Openswan Users] ipsec verify reports "IP forwarding failed"

[Steve Zeng]

Anybody has an idea of how ipsec verify works. I run it and it always tells me that ipforwarding failed. 

#ipsec verify
Checking your system to see if IPsec got installed and started correctly:
Version check and ipsec on-path                                 [OK]
Linux Openswan U2.6.24rc5/K2.6.18-53.el5 (netkey)
Checking for IPsec support in kernel                            [OK]
NETKEY detected, testing for disabled ICMP send_redirects       [OK]
NETKEY detected, testing for disabled ICMP accept_redirects     [OK]
Checking for RSA private key (/etc/ipsec.secrets)               [OK]
Checking that pluto is running                                  [OK]
Pluto listening for IKE on udp 500                              [OK]
Pluto listening for NAT-T on udp 4500                           [FAILED]
Two or more interfaces found, checking IP forwarding            [FAILED]
Checking NAT and MASQUERADEing                                  [OK]
Checking for 'ip' command                                       [OK]
Checking for 'iptables' command                                 [OK]
Opportunistic Encryption Support                                [DISABLED]

I am running openswan-2.6.24rc5-1 on centos-5.1-i386. I can tell ip_forward is enabled by running:

#sysctl -A | grep ip_forward
net.ipv4.ip_forward = 1

thanks in advance,

Steve