Author: René Jorissen

René Jorissen works as Solution Architect for QMonkeys in the Netherlands. Network Infrastructures are the primary focus. René works with equipment of multiple vendors, like HPE Networks, FortiNet, SentinelOne, Phished, Holm Security, Microsoft services and many more. René is Aruba Certified Edge Expert (ACEX #26), Aruba Certified Mobility Expert (ACMX #438), Aruba Certified ClearPass Expert (ACCX #725), Aruba Certified Design Expert (ACDX #760), CCNP R&S, FCNSP and Certified Ethical Hacker (CEF) certified. You can follow René on Twitter and LinkedIn.

Configuration Example, Management

IPplan – IP address management

René Jorissen on September 30, 2009 • 5 Comments • Tags: #address #cacti #cactiez #dynamic #ip #ipam #ipplan #management #nmap

A lot of customers have different methods for their IP address management. Most of them use some kind of static documentation, like an Excel sheet. In the past I implemented IPplan multiple times. I like this tool, because it dynamically scans multiple IP subnets, using ICMP and/or Nmap. Another advantage of IPplan is its ability … Read More

Configuration Example

OpenSSL & Cygwin – Certificate Authority

René Jorissen on September 30, 2009 • 0 Comments • Tags: #authority #certificate #cygwin #howto #openssl

I am using OpenSSL in conjunction with Cygwin on my Windows laptop to generate Certificate Signing Request and other SSL certificate related issues. Today I configured my own Certificate Authority, using the following guideline. Preparations First I created some directories, like shown below: mkdir /home/sslCAcd /home/sslCAmkdir certs private newcerts Next I created a serial file … Read More

Mail relaying

Barracuda – Mail Protocol Violation

René Jorissen on September 8, 2009 • 1 Comment • Tags: #barracuda #firewall #mail #protocol #spam #violation

A customer updated the firmware from a Barracuda SPAM &Virus 300 firewall. The firmware was upgraded from version 3.4 to version 3.5.12.024. After the upgrade no email was coming in or going out through the Barracuda firewall. All email was blocked and the following reason was visible in the message log: Mail Protocol Violation At … Read More

Firewalling, Security

Cisco ASA: DNS reply filtering

René Jorissen on August 28, 2009 • 7 Comments • Tags: #asa #cache #class #dns #drop #expression #filtering #inspect #inspection #map #policy-map #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

IPSec / SSL VPN, Security

Redundant DMVPN network

René Jorissen on August 20, 2009 • 0 Comments • Tags: #authenticate #cloud #dmvpn #dual #dynamic #eigrp #hub #isakmp #multicast #multipoint #network-id #nhrp #redundant #resilient #single #spoke #vpn

Today I looked at the configuration DMVPN (Dynamic Multipoint VPN). A Dynamic Multipoint Virtual Private Network is an enhancement of the virtual private network (VPN) configuration process of Cisco IOS-based routers. DMVPN prevents the need for pre-configured (static) IPsec peers in crypto-map configurations and ISAKMP peer statements. This feature of Cisco IOS allows greater scalability … Read More

Proxy

eSafe Gateway 7.1 Forwarding Proxy with squid

René Jorissen on August 5, 2009 • 0 Comments • Tags: #71 #enable #esafe #forwarding #gateway #proxy #squid #squidconf

My colleague over at PBSPlaza wrote a nice article about enabling squid on eSafe Gateway 7.1 Forwarding Proxy. Today I had to configure an extra step to enable squid. I followed the instructions from my colleague, but when I tried to start squid I received the following error message. FATAL: Could not determine fully qualified … Read More