Cisco ASA Redundant or Backup ISP Links with VPNs
KB ID 0000544 Problem This method provides failover to a redundant ISP link should your primary network connection go down. IT IS NOT going to load balance the traffic across both interfaces. In this example I’ve also got a VPN to a remote site and some port forwarding to contend with as well. Where we are at the start. Where we want to be Solution Before you go any further the ASA that will have the backup ISP line,...
Cisco ASA 5500 – Reset / Recycle VPN Tunnels
KB ID 0000586 Problem I’ve been asked this before and it came up on EE today, basically you have a site to site VPN tunnel and you either want to restart it or reset it. Solution Cisco ASA Reset ALL VPN Tunnels 1. Connect to your ASA, then to reset ALL your ISAKMP VPN tunnels use the following command; clear crypto isakmp sa In the example below I’ve reset ALL my tunnels. I had a constant ping running across the VPN, and...
Cisco Firewall (ASA/PIX) – Granting Access to an FTP Server
KB ID 0000772 Problem If you have an FTP server, simply allowing the FTP traffic to it wont work. FTP (in both active and passive mode) uses some random high ports that would normally be blocked on the firewall. So by actively inspecting FTP the firewall will know what ports to open and close. Solution How you ‘allow’ access to the FTP server will depend on weather you have a public IP address spare or not, if you only...
Cisco ASA – Configuring for NTP
KB ID 0000608 Problem With NTP, there will be two things you want to do, 1) Allow a device behind the ASA to take its time from a public NTP server, and 2) Set the ASA to take its system time from a public NTP sever (for accurate date stanps on the logs, and for time critical things like Kerberos authentication.) Solution Allow internal host(s) to get system time though the firewall. 1. Connect to the ASA, go to “enable...