OpenSSL & Cygwin – Certificate Authority
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
Barracuda – Mail Protocol 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
Cisco ASA: DNS reply filtering
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
Redundant DMVPN network
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
eSafe Gateway 7.1 Forwarding Proxy with squid
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
Cisco banners with SSH
When configuring a Cisco device I always configure some kind of banner, which is displayed when logging in. This banner contains some information, like security warnings and general information. There are different kind of banners. exec: display a banner before displaying the enable prompt; login: display a banner before the password login prompt when accessing … Read More