Network Time Tools (NTT) is a set of network tools designed to provide monitoring of a network and the services on that network, and provide various reports on the hosts/services and optional alerts via email, pager, and cellphones. It comes with a protocol scanner, a bandwidth measurement tool, and a CGI front end that can handle a regular browser or WAP-enabled cellphones via WML.
The Spoofaudit network auditing tool will help you to determine what basic spoofing filters (rfc2827 & rfc3013) are present between two test points on two networks, and what anti-spoofing filters are missing. The tools are designed to work between endpoints that would not normally have filtering between them except anti-spoofing filters.
RFC 2015 defines a proposed Internet standard for sending PGP-encrypted email. This PGP/MIME has been incorporated into several MUAs such as Mutt and (with the AEGYPTEN project) KMail. However, a lot of email clients still don't support it. pgp-mime-handler can decrypt/verify such messages via a pipe, so it can be used as an email filter in many programs or scripts.
IP-packetgenerator is a (ICMP/UDP/TCP)/IP packet generator written in Perl. When creating a TCP packet, it lets you specify the source and destination IP address, source and destination port, sequence and acknowledgement number, window size, and TCP flags. When creating a UDP packet, it lets you specify the source and destination IP and source and destination port. When creating an ICMP packet, it lets you specify the type, code, and mtu. Additionally, you can set the Time-to-live, set the fragmentation offset, send data within the packets, and select the number of packets to send over the wire. There are commandline and GUI versions. The configuration of packets can be read from a config file or saved to a config file.
Come And Go Encryption (CAG) is a simple program to encrypt files with a special key. This key is a random garbage file, and it is XOR-ed with the file to render it unusable by normal methods. It uses the principle of the one-time pad, but it is not unbreakable. It can stream the decrypted file to STDOUT for use in pipes (i.e., mplayer movie viewing, xv image viewing, etc.).