Enabling NetFlow on Cisco ASA
KB ID 0000055 Problem Cisco NetFlow lets you export information about traffic flow, it was originally written for the router IOS, but is now available for Cisco ASA, which uses NSEL (Note ASA uses NetFlow version 9 {newest at time of writing}) Note: NetFlow can not give you “Live” data, but it can show you what has happened over a period of time, and remember like any other “Logging” this will have an adverse...
Cisco ASA – Only Allow Mail Servers SMTP Outbound
KB ID 0000172 Problem It’s not unusual for nasty Virus’s and Malware once they have infected a machine, to set up outbound communications on the mail protocol SMTP (TCP Port 25), which can lead to your public address being blacklisted. So it’s considered good practice to stop all your clients getting mail access outbound through your firewall, while still allowing your mail server. Note: On Cisco firewall’s,...
Cisco Firewalls Changing the Web Management Port
Cisco 5500 Changing the ASDM Port Unable to Port Forward HTTPS KB ID 0000268 Problem You want to change the port that the Cisco ASDM runs over, or you are attempting to port forward https/ssl and see the following error Error: ERROR: unable to reserve port 443 for static PAT ERROR: unable to download policy You are trying to port forward (Create a static PAT entry) on a Cisco ASA for port 443 / https. This port is in use by the ASDM....
Upgrade Cisco PIX 515E to Version 8.0(4)
and ASDM version 6.1(5) KB ID 0000424 Problem I had to update a Cisco PIX 515E last week, Cisco 500 firewalls are a bit thin on the ground these days, and most of my corporate clients have replaced then with Cisco ASA 5500 firewalls. So as these units are now getting retired, or moved to the test bench, or sold on ebay. I thought I’d document probably the last one I did for posterity, and to help anyone else out. Note: Cisco...
Cisco ASA – Global Access Lists
KB ID 0001019 Problem I’ve been working for a client that has a large firewall deployment, and they have twelve switches in their six DMZ’s. I wanted to take a backup of these switches (and all the other network devices). While I was bemoaning the amount of ACL’s that I would need to allow TFTP in from, (note: that’s UDP port 69 if you are interested). My colleague said “Why not use a global ACL?”,...