Configuration Example, Proxy, Security

Change password through LDAPS on ISA server

René Jorissen on August 6, 2008 0 Comments • Tags: #2006 #authority #ca #fqdn #isa #key #ldaps #private #proxy #reverse #set #user

Today I received the question about allowing users to changes his/her password through webmail, whereby webmail is published via an ISA server 2006 reverse proxy. This is possible, but it requires the configuration of LDAPS to authenticate users. I started by configuring a Certificate Authority (CA) on a member server in the domain. During the … Read More

Configuration Example, Routing, Security, Switching

Secure HSRP configuration

René Jorissen on July 25, 2008 2 Comments • Tags: #authenticate #cdp #clear #dtp #hsrp #keystring #md5 #preempt #priority #spoofing #standby #text #timeout #wireshark #yersinia

A friend of mine works for a well known auditing and penetration testing company in the Netherlands. Recently we were talking about how he starts looking for flaws in network infrastructures. My friend told me that the first thing he does is simply starting WireShark and start looking at all the packets he receives. By … Read More

Configuration Example

Auto Backup Configurations

René Jorissen on July 21, 2008 2 Comments • Tags: #archive #auto #backup #configurations #cron #occurrence

Till recently I didn’t have a decent way to backup configurations from routers and switches without using some kind of management tool, like Cacti or Nagios. I wanted to automatically backup configurations by only using a TFTP or FTP server on a network. I started looking and found the solution by using the archive and … 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

Configuration Example, Routing

Policy-Based Routing Catalyst 3560

René Jorissen on June 30, 2008 13 Comments • Tags: #3560 #based #pbr #policy #routemap #routing

Today I visited a customer where the power a Cisco Catalyst 3548XL blew up. The switch had a manufacture date of December 2000. It is an old one, but still I haven’t seen a power supply being blown up from a Cisco switch from that age. But oké, the switch needed to be replaced. The … Read More

Configuration Example, Security

MAC Authentication Bypass – Continued

René Jorissen on June 20, 2008 1 Comment • Tags: #8021x #authenticate #bypass #caveats #guestvlan #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