Free dns server software for linux

Dual DHCP DNS Server is a combined DHCP/DNS server for small LANs.
Dynamic DHCP allocates/renews host addresses, while the caching DNS server first tries resolving from DHCP-allotted names, then from cache, and only then forwarding to external DNS servers.
Dual DHCP DNS Server supports an optional static DHCP mode and static IPs, automatic dynamic DNS updates from DHCP, and the ability to co-exist with other DHCP servers.
It is self-configuring and doesnt require the creation of zone files, and uses little memory and CPU.
Enhancements:
- This release fixes zone replication bugs.

DeniX Server OS is an independent Linux based distribution built from scratch by Denis Salmanovich. They aim to offer a user-friendly full-featured server operating system, pre-configured, well structured and easy to work with, and filled with the latest stable versions of Linux apps.
Its easy to install and configure. Every package is downloaded from the authors source and compiled when installed.
Main features:
- Domain Controller
- ADSL/CABLE Router (PPPoE)
- Network Firewall
- Anti Virus Gateway
- Anti Spam Gateway
- Mail Server (local & external) + Web Mail
- Calendar Sharing Support
- Network File Server
- DHCP Server
- TFTP BOOT Server
- WINS Server
- FTP Server
- VPN Server
- DNS Server
- DDNS Server
- MySQL Server
- HTTP Apache Server
- Remote Backup Solutions
- Remote control and administration
- Print Queue Server
- Proxy Server

Messa is an instant messager client and server. The client has a curses interface and works on the console.

Messa project supports multilingual messages and private messages. The server supports monoprocess operation (without threads), the ability to choose the listening port, and the ability to run under the console.

DNS name parser is a Java utility library for parsing dns names, ip and hw addresses.

Synopsis

import su.netdb.parser.*;

Parser parser = new Parser();

Hashtable result = parser.parse(str);

System.out.println("string: "+result.get("string"));
System.out.println("hw: "+result.get("hw"));
System.out.println("name: "+result.get("name"));
System.out.println("domain: "+result.get("domain"));
System.out.println("ip_low: "+result.get("ip_low"));
System.out.println("ip_high: "+result.get("ip_high"));

"DNS name parser" is an utility library created to be used in a search application. Given a single input field its function is to differentiate between several types of possible input strings. Namely if it a dns name, IP address (exact, ip range or ip with wildcards) or hardware address. The result of the parsing is a Hashtable with possible keys "string", "hw", "name", "domain", "ip_low" and "ip_high".

Dnstracer determines where a given Domain Name Server (DNS) gets its information from, and follows the chain of DNS servers back to the servers which know the data.
Enhancements:
- Better handling of timeout (instead of a static value, start with five seconds and double it each retry)
- Warnings are printed if you receive a different RR type than the one you asked for (for example when you ask for an A record and receive a CNAME)
- Fixed problems when records received in the authority field are shorter than the domain the nameserver is authoritative for.
- When compiled without IPv6 support on an IPv6 capable machine the machine tried to query the IPv6 translated IPv5 address anyway.
- -C caches hosts which havent answered too.

Run a web server inside LAN is a simple script to run a WWW server inside a Local Area Network. Run a web server inside LAN script assume all iptables features are compiled statically in the kernel, or all modules are loaded.

Otherwise you may encounter some surprises trying to utilize the more featureful and creative commandlines that Ive come up with.

Sample:

#external and internal interfaces
EXT=eth0
INT=eth1

# clear everything, and create my cascading chains
iptables -F
iptables -N e0
iptables -N tcpin
iptables -N udpin

# e0 is the name of our chain for eth0
iptables -I INPUT -i $EXT -j e0

# OUTPUT Chain
iptables -A OUTPUT -o $EXT -j DROP -p icmp --icmp-type ! echo-request

# remote gnutella queries were really pissing me off one day
# iptables -A OUTPUT -o $EXT -j DROP -p tcp ! --syn --dport 6346
# iptables -A OUTPUT -o $EXT -j DROP -p tcp ! --syn --sport 6346

# $EXT Chain
# a single rule to accept SYN Packets for multiple ports (up to 15)
iptables -A tcpin -j ACCEPT -p tcp --syn -m multiport --destination-ports 873,993,995,143,80,113,21,22,23,25,53

# stateful connection tracking is wonderful stuff
# ESTABLISHED tcp connections are let through
# If we send a SYN out, the ACK is seen as RELATED
# then further communication is accepted by the ESTABLISHED rule
iptables -A e0 -j ACCEPT -m state --state ESTABLISHED
iptables -A e0 -j ACCEPT -m state --state RELATED

# certain ports I simply DROP
iptables -A tcpin -j DROP -p tcp --syn -m multiport --destination-ports 6346,139

# UDP rules...
iptables -A udpin -j DROP -p udp -m multiport --destination-ports 137,27960

# I run a DNS server, so we must accept UDP packets on port 53
iptables -A udpin -j ACCEPT -p udp -m state --state NEW --destination-port 53

# lets log NEW udp packets on ports 1024:65535, then let them through
iptables -A udpin -j LOG -p udp -m state --state NEW --destination-port 1024:65535 --log-level debug --log-prefix UDPNEW --log-ip-options
iptables -A udpin -j ACCEPT -p udp -m state --state NEW --destination-port 1024:65535

# lets log NEW tcp packets on ports 1024:65535, then let them through
iptables -A tcpin -j LOG -p tcp --syn --destination-port 1024:65535 --log-level debug --log-prefix TCPNEW --log-tcp-options --log-ip-options
iptables -A tcpin -j ACCEPT -p tcp --syn --destination-port 1024:65535

# lets log INVALID or NEW tcp packets on priveleged ports, then DROP
# (remember I have certain ACCEPT rules higher up the chain)
iptables -A tcpin -j LOG -p tcp -m state --state INVALID,NEW --destination-port 1:1023 --log-level warn --log-prefix TCPPRIV --log-tcp-options --log-ip-options
iptables -A tcpin -j DROP -p tcp -m state --state INVALID,NEW --destination-port 1:1023

iptables -A e0 -p tcp -j tcpin
iptables -A e0 -p udp -j udpin
iptables -A e0 -j LOG --log-level debug --log-prefix NETFILTER --log-ip-options -m state --state INVALID,NEW
iptables -A e0 -j DROP

# NAT Rules
# I run a web server inside...
iptables -t nat -A PREROUTING -p tcp -i eth0 --dport 80 -j DNAT --to-destination 192.168.1.4:80