Update Cisco ASA – Directly from Cisco (via ASDM)
KB ID 0000636 Problem Warning: Before upgrading/updating the ASA to version 8.3 (or Higher) Check to see if you have the correct amount of RAM in the firewall (“show version” command will tell you). This is VERYIMPORTANT if your ASA was shipped before February 2010. See the link below for more information. ASA – Memory Error (Post upgrade to version 8.3) Warning 2: Be aware, if you are upgrading to an OS of...
Cisco ASA 5500 – Using a Third Party Digital Certificate
(For Identification, AnyConnect, and SSL VPN) KB ID 0000694 Problem A client asked me how to do this, so off I went to the test bench to work it out. Note: I’m this example In going to submit the request to, and issue the certificate from, my own windows domain certificate authority, you would send your request to a third party certificate authority, here’s a direct link to the certificate type you require. To use your own...
Cisco ASA – Using ‘logging’ to see what ports are being blocked
KB ID 0000702 Problem If you look after a firewall, sooner or later something will fail, and the blame (rightly or wrongly), will be leveled at the firewall. I came back from holiday this week to find a client had got a problem with secure POP email. The problem had been fixed (temporarily) by dropping the affected users into a group, and opening all ports. As this had fixed the problem then it’s fair to say that the ASA was...
Cisco ASA to Juniper SRX Site to Site VPN
KB ID 0000710 Problem You want to establish a site to site VPN from a site with a Cisco ASA firewall, to another site running a Juniper SRX firewall. I had to do this this week, and struggled to find any good information to help. In the example below I’m configuring the whole thing from a laptop (172.16.254.206) that’s on the Juniper’s site. Use the diagram below, and substitute your own IP addresses and subnet...
Cisco ASA 5500 Active/Standby – Zero Downtime Upgrade
KB ID 0000733 Problem You have two ASA firewalls deployed in Active/Standby failover configuration, and need to upgrade either the operating system or the ASDM. As you already have a high availability solution you do not want any downtime. Before we start, we need to make sure we know the difference between primary, secondary, active and standby. From the rear (Active=Green, Standby=Amber) The Primary and Secondary firewalls are...