Sonicwall GVC VPN: Unable to connect to VPN. Error: “Packet length mismatch with interface MTU”

I had a client who was unable to connect to the Sonicwall VPN via GVC (Global VPN Client). Packet capture showed initial inbound traffic to the Sonicwall from Client is being dropped. Logs as below: 50 03/30/2016 14:16:06.912 X4*(i) -- VPN.CLIENT.IP.HERE SONICWALL.WAN.IP.HERE IP UDP 500,500 DROPPED 60[60] 51 03/30/2016 14:16:06.912 X4*(i) -- VPN.CLIENT.IP.HERE SONICWALL.WAN.IP.HERE IP … Continue reading Sonicwall GVC VPN: Unable to connect to VPN. Error: “Packet length mismatch with interface MTU”

Fortigate: Log Monitoring and Email Alerting via Fortianalyzer

Using the logs sent by your Fortigate Firewall to your Fortianalyzer, you can set up an monitoring/alerting function for any logs or events captured. This is very helpful in monitoring critical systems and functions such as interface flaps or VPN IPsec Issues. You can monitor any events as long as it is logged.  In this … Continue reading Fortigate: Log Monitoring and Email Alerting via Fortianalyzer

Fortigate: Set up the Health Link Monitor

Health Link Monitor (as known as dead gateway detection) is used to for multiple WAN setup to monitor the status of the links and force a failover if necessary. Set up the Health Link Monitor and configure ping servers The following will ping a server of your choice, and if it stops receiving replies at … Continue reading Fortigate: Set up the Health Link Monitor

Fortigate: Disabling and enabling the SIP session helper

You can use the following steps to disable the SIP session helper. You might want to disable the SIP session helper if you don’t want the FortiGate to apply NAT or other SIP session help features to SIP traffic. With the SIP session helper disabled, the FortiGate can still accept SIP sessions if they are … Continue reading Fortigate: Disabling and enabling the SIP session helper

Trick: How to copy files into Linux from Windows Machine

In Unix, you can use SCP (the scp command) to securely copy files and directories between remote hosts without starting an FTP session or logging into the remote systems explicitly. The scp command uses SSH to transfer data, so it requires a password or passphrase for authentication. Unlike rcp or FTP, scp encrypts both the … Continue reading Trick: How to copy files into Linux from Windows Machine

Fortigate: Best Practices Guide (per Topic)

This Best Practice Guideline for Fortigate is compiled from both FortiOS 5.2 and 5.4 for common issues encountered by myself and shared to everyone to ensure the most secure and reliable operation of our Fortigate units. This is updated periodically as I come across known issues and best practice recommendations. A. General Configurations  Below are … Continue reading Fortigate: Best Practices Guide (per Topic)