Free forwarder software for linux

NBFW is a smb forwarder. With the Samba NetBIOS forwarder, nbfw, you can browse the local windows network transparently to and from your masqueraded network.

This will most likely be of use for people who have Windows machines on a backend network who want to browse the Network Neighbourhood on the normal network though their masquarading firewall.

If your Samba is not working ok, NBfW will not work, too. NBfW can cause major problems if you dont configure it correctly. And it has ... It really helps to know what youre doing.

lamefwd provides an easy-to-use single process port forwarder.
lamefwd is an easy-to-use single process port forwarder, handling both TCP and UDP protocols. It is intended to be a fast and lightweight alternative to portfwd.
Usage
On BSD and Linux use "./configure ; make", on Windows run the installer. Then just edit lamefwd.cfg before starting the program:
#
# example config file for lamefwd
#
# localport remotehost remoteport protocol
#
5000 test.host.se 50 tcp
5005 test.host.se 55 udp
Enhancements:
- This release adds support for automated building using "./configure ; make" on *BSD, Linux, and Cygwin systems.

m0n0wall is a project aimed at creating a complete, embedded firewall software package that, when used together with an embedded PC, provides all the important features of commercial firewall boxes (including ease of use) at a fraction of the price (free software).
m0n0wall is based on a bare-bones version of FreeBSD, along with a web server, PHP and a few other utilities. The entire system configuration of m0n0wall is stored in one single XML text file to keep things transparent.
m0n0wall is probably the first UNIX system that has its boot-time configuration done with PHP, rather than the usual shell scripts, and that has the entire system configuration stored in XML format.
Main features:
- web interface (supports SSL)
- serial console interface for recovery
- set LAN IP address
- reset password
- restore factory defaults
- reboot system
- wireless support (access point with PRISM-II/2.5/3 cards, BSS/IBSS with other cards including Cisco)
- captive portal
- 802.1Q VLAN support
- stateful packet filtering
- block/pass rules
- logging
- NAT/PAT (including 1:1)
- DHCP client, PPPoE, PPTP and Telstra BigPond Cable support on the WAN interface
- IPsec VPN tunnels (IKE; with support for hardware crypto cards and mobile clients)
- PPTP VPN (with RADIUS server support)
- static routes
- DHCP server
- caching DNS forwarder
- DynDNS client
- SNMP agent
- traffic shaper
- SVG-based traffic grapher
- firmware upgrade through the web browser
- Wake on LAN client
- configuration backup/restore
- host/network aliases
Enhancements:
- added voucher support to captive portal (mwiget); wireless LAN improvements; allow dashes in alias names; added hidden option to disable auto-generation of PPTP rules on WAN; fixed ATA hard disk spin down feature; ipfilter TCP window scaling bug fix; synced with changes from 1.23 branch; increased mfsroot size to 14 MB (from 13 MB); updated base system to FreeBSD 6.2-RELEASE-p6; updated PHP to 4.4.7, ipsec-tools to 0.6.7, isc-dhcpd to 3.0.5, Dnsmasq to 2.39; added kernel patch for fragment bug in ipfilter; modified kernel patch to handle ipnat+dummynet in ip_input....

Simple UDP proxy/pipe is an advanced UDP proxy/datapipe/packets forwarder and modifier with multiple functions.

Multiple clients allowed (you can connect many clients you want to this proxy), creation of ACP files (tcpdump capture files, just like a sniffer), packets forwarding (chat style, each packet is forwarded to all the other clients and server connected), packets injection (the tool opens a specific UDP port where you can send your customized packets which will be sent to the server), hexadecimal visualization and plugins support for the modification and visualization of the packets with some example plugins already included (Zdaemon huffman, Doom huffman, Half-life decoding and one for the replacement of the text strings).

Plugins (which work on both Windows and Linux) are very basic to create and use, just take a look at example_sudp.c for more informations.

Dnsmasq is lightweight, easy to configure DNS forwarder and DHCP server. Dnsmasq is designed to provide DNS and, optionally, DHCP, to a small network. It can serve the names of local machines which are not in the global DNS.
The DHCP server integrates with the DNS server and allows machines with DHCP-allocated addresses to appear in the DNS with names configured either in each host or in a central configuration file. Dnsmasq supports static and dynamic DHCP leases and BOOTP for network booting of diskless machines.
Dnsmasq is targeted at home networks using NAT and connected to the internet via a modem, cable-modem or ADSL connection but would be a good choice for any small network where low resource use and ease of configuration are important.
Supported platforms include Linux (with glibc and uclibc), *BSD and Mac OS X. Dnsmasq is included in at least the following Linux distributions: Gentoo, Debian, Slackware, Suse, Smoothwall, IP-Cop, floppyfw, Firebox, LEAF, Freesco, CoyoteLinux and Clarkconnect. It is also available as a FreeBSD port and is used in Linksys wireless routers and the m0n0wall project.
Main features:
- The DNS configuration of machines behind the firewall is simple and doesnt depend on the details of the ISPs dns servers
- Clients which try to do DNS lookups while a modem link to the internet is down will time out immediately.
- Dnsmasq will serve names from the /etc/hosts file on the firewall machine: If the names of local machines are there, then they can all be addressed without having to maintain /etc/hosts on each machine.
- The integrated DHCP server supports static and dynamic DHCP leases and multiple networks and IP ranges. It works across BOOTP relays and supports DHCP options including RFC3397 DNS search lists. Machines which are configured by DHCP have their names automatically included in the DNS and the names can specified by each machine or centrally by associating a name with a MAC address in the dnsmasq config file.
- Dnsmasq caches internet addresses (A records and AAAA records) and address-to-name mappings (PTR records), reducing the load on upstream servers and improving performance (especially on modem connections).
- Dnsmasq can be configured to automatically pick up the addresses of its upstream nameservers from ppp or dhcp configuration. It will automatically reload this information if it changes. This facility will be of particular interest to maintainers of Linux firewall distributions since it allows dns configuration to be made automatic.
- On IPv6-enabled boxes, dnsmasq can both talk to upstream servers via IPv6 and offer DNS service via IPv6. On dual-stack (IPv4 and IPv6) boxes it talks both protocols and can even act as IPv6-to-IPv4 or IPv4-to-IPv6 forwarder.
- Dnsmasq can be configured to send queries for certain domains to upstream servers handling only those domains. This makes integration with private DNS systems easy.
- Dnsmasq supports MX records and can be configured to return MX records for any or all local machines.
Enhancements:
- This release adds some features to the log subsystem: it is now possible to log directly to a file, and to log asynchronously to syslog.
- More detailed logging of DHCP transactions is available.
- DHCP options can now be specified by name instead of by number.
- DHCP configuration can now use information from a DHCP relay agent.
- There are a few minor bugfixes (notably failure of TFTP with --listen-address).
- Some translations have been updated.