Security

Serious DNS Vulnerability

René Jorissen on July 24, 2008 0 Comments • Tags: #dan #dns #kaminsky #vulnerability

I guess you already read about it, but if not here a short outcome. Despite Dan Kaminsky’s efforts to keep a lid on the details of the critical DNS vulnerability he found, someone at the security firm Matasano leaked the information on its blog yesterday, then quickly pulled the post down. But not before others … Read More

Proxy, Security

ISA 2006 Authentication over HTTP

René Jorissen on July 8, 2008 0 Comments • Tags: #12250 #2003 #2007 #403 #authenticate #block #code #error #exchange #forwarding #http #over #owa #proxy #requests #require #reverse

I implemented different ISA 2006 Reverse Proxy servers in conjunction with Microsoft Exchange 2003 or Windows Exchange 2007. Today I configured ISA 2006 with Exchange 2007. I configured the Reverse Proxy server as I did always. And the connection from outside the network works perfectly. On the internal Exchange server I configured Basic and Integrated … Read More

Configuration Example, Security, Switching

Layer 2 security

René Jorissen on July 6, 2008 2 Comments • 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

Security

Wired 802.1X

René Jorissen on June 24, 2008 0 Comments • Tags: #8021x #authenticate #bypass #iab #inaccessible #wired

The session about wired 802.1X deployment was really interesting. I was stunned about the information I already knew after my testing with MAC Authentication Bypass last week. Of course the speaker had more configuration options when configuring the switch ports. Important for me to hear where the ways for deploying 802.1X in environments. It isn’t … Read More

Firewalling, Security

Cisco IOS Security

René Jorissen on June 24, 2008 0 Comments • Tags: #cisco #classic #firewalling #ios #zone-based

The first session I attended is about Deploying IOS Security. The session is about using the Cisco IOS as firewall to protect branch offices. We discussed normal classic firewalling and zone-based firewalling. I normally use classing firewalling, but I guess I have to try zone-based firewalling in the future. The advantage of zone-based firewalling is … Read More

Configuration Example, Security

MAC Authentication Bypass – Continued

René Jorissen on June 20, 2008 1 Comment • Tags: #8021x #authenticate #bypass #caveats #guest-vlan #ias #lan #mac #nac #nap #on #radius #wake #wol

Finally I had a day “off” and could test MAC Authentication Bypass (MAB) in our test environment at the office. I created the following test environment: There are 4 different VLAN’s and a Cisco Catalyst 3750 connects the VLAN’s to each other. I wanted to create an environment with the following properties: All switch ports … Read More