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If certificates have been used in a VPN solution then the following should be looked at as a source
of potential problems:
• Check that the correct certificates have been used for the right purposes.
• Check that the certificate .cer and .key files have the same filename. For example, my_cert.key
and my_cert.cer.
• Check that the certificates have not expired. Certificates have a specific lifetime and when this
expires they cannot be used and new certificates must be issued.
• Check that the NetDefendOS date and time is set correctly. If the system time and date is wrong
then certificates can appear as being expired when, in fact, they are not.
• Consider time-zone issues with newly generated certificates. The NetDefend Firewall's time
zone may not be the same as the CA server's time zone and the certificate may not yet be valid
in the local zone.
• Disable CRL (revocation list) checking to see if CA server access could be the problem. CA
Server issues are discussed further in Section 9.6, “CA Server Access”.
9.7.3. IPsec Troubleshooting Commands
A number of commands can be used to diagnose IPsec tunnels:
The ipsecstat console command
ipsecstat can be used to show that IPsec tunnels have correctly established. A representative
example of output is:
gw-world:/> ipsecstat
--- IPsec SAs:
Displaying one line per SA-bundle
IPsec Tunnel Local Net Remote Net Remote GW
------------ -------------- ------------ -------------
L2TP_IPSec 214.237.225.43 84.13.193.179 84.13.193.179
IPsec_Tun1 192.168.0.0/24 172.16.1.0/24 82.242.91.203
To examine the first IKE negotiation phase of tunnel setup use:
gw-world:/> ipsecstat -ike
To get complete details of tunnel setup use:
gw-world:/> ipsecstat -u -v
Warning: Be careful using the -num=all option
When using any IPsec related commands, if there are large numbers of tunnels then
avoid using the -num=all option since this will generate correspondingly large
amounts of output.
For example, with a large number of tunnels avoid using:
gw-world:/> ipsecstat -num=all
9.7.3. IPsec Troubleshooting
Commands
Chapter 9. VPN
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