Firewalling, Security

Cisco ASA: DNS reply filtering

RenĂ© Jorissen on August 28, 2009 7 Comments • Tags: #asa #cache #class #dns #drop #expression #filtering #inspect #inspection #map #policymap #regex #regular #request #url

Today I was asked to block access to multiple websites and the only device capable of doing this was the firewall. This customer is using a Cisco ASA firewall, which supports basic URL filtering. This customers wanted to block HTTP and HTTPS websites. HTTPS websites use a SSL tunnel from the end device to the … Read More

Configuration Example, Security, Switching

Layer 2 security

RenĂ© Jorissen on July 6, 2008 1 Comment • Tags: #address #arp #attacks #bpduguard #dhcp #dynamic #hopping #inspection #ip #layer #mac #rootguard #source #spoofing #two #vlan

I attended the session layer 2 security, because I had some discussions about layer 2 security with one of my colleagues. We were discussing about using layer 2 security and especially implementing it in the environments from our customers. Looking at my/our customers, I don’t see environments where layer 2 threats would be immediate. But … Read More