06-01-2011
Quote:
Originally Posted by
garric
I want to open specific ports at the output and block the rest. Putting the default output blocking policy would make the machine unusable. Thus, I shifted it to the bottom the firewall script and that worked. Anything I am doing wrong here?
The default policy takes immediate effect when set, that's true. However, it only blocks you out if you enter the commands manually, which should be the exception, not the rule. When using a script you can set the default policy first, and then open the ports you need without interrupting any traffic.
10 More Discussions You Might Find Interesting
1. IP Networking
Hi
I have small home network and I want to block some forums on web
When I use this
iptables -A INPUT -s forum -j DROP
rules is applied but when I restart some of PC rules are not present any more also I tried to save firewall settings
iptables-save > /root/dsl.fw
but how to... (2 Replies)
Discussion started by: solaris_user
2 Replies
2. Red Hat
Please i need help in how to add/remove rules in timezone files under /usr/share/zoneinfo/ , cause i have tried many times to do this by adding rules in an time zone file then compile this file with zic tool and then link it to /etc/localtime but always the output doesn't match what i have made... (0 Replies)
Discussion started by: linuxroOot
0 Replies
3. Ubuntu
Could someone help me with writing rules for iptables?
I need a dos attacks protection for a game server.
port type udp
ports 27015:27030
interface: eth0
Accept all packets from all IPs
Chek if IP sent more than 50 packets per second
Drop all packets from this IP for 5 minutes
I would be... (0 Replies)
Discussion started by: Greenice
0 Replies
4. Red Hat
Hi Gurus,
I need to add Multicast Port = xyz
Multicast Address = 123.134.143 ( example) to my firewall rules. Can you please guide me with the lines I need to update my iptables files with. (0 Replies)
Discussion started by: rama krishna
0 Replies
5. Red Hat
Hi Champs
i am new in Iptables and trying to write rules for my Samba server.I took some help from internet, created one script and run from rc.local :
#Allow loopback
iptables -I INPUT -i lo -j ACCEPT
# Accept packets from Trusted network
iptables -A INPUT -s my-network/subnet -j... (0 Replies)
Discussion started by: Vaibhav.T
0 Replies
6. UNIX for Advanced & Expert Users
Hello,
I have iptables service running on my CentOS5 server. It has approx 50 rules right now.
The problem I am facing now is as follows -
I have to define a new chain in the filter table, say DOS_RULES & add all rules in this chain starting from index number 15 in the filter table.
... (1 Reply)
Discussion started by: BhushanPathak
1 Replies
7. Shell Programming and Scripting
Need to convert the QNX rules to Linux ubuntu 12.04. kindly any one help us with any tools (4 Replies)
Discussion started by: mageshkumar
4 Replies
8. UNIX for Advanced & Expert Users
Hi,
I've been struggling with this all morning and seem to have a blind spot on what the problem is. I'm trying to use iptables to block traffic on a little cluster of raspberry pi's but to allow ssh and ping traffic within it.
The cluster has a firewall server with a wifi card connecting to... (4 Replies)
Discussion started by: steadyonabix
4 Replies
9. Cybersecurity
Hello,
I did 2 scripts. The second one is, I hope, more secure.
What do you think?
Basic connection (no server, no router, no DHCP and the Ipv6 is disabled)
#######script one
####################
iptables -F
iptables -X -t filter
iptables -P INPUT DROP
iptables -P FORWARD... (6 Replies)
Discussion started by: Thomas342
6 Replies
10. IP Networking
Hi, I am relatively new to firewalls and netfilter. I have a Debian Stretch router box running dnsmasq, connected to a VPN. Occasionally dnsmasq polls all of the desired DNS servers to select the fastest. When it does this it responds to replies of the non-selected DNS servers with a icmp type... (0 Replies)
Discussion started by: CrazyDave
0 Replies
LEARN ABOUT DEBIAN
fwb_pf
fwb_pf(1) Firewall Builder fwb_pf(1)
NAME
fwb_pf - Policy compiler for OpenBSD packet filter "pf"
SYNOPSIS
fwb_pf [-vVx] [-d wdir] [-o output.fw] [-i] -f data_file.xml object_name
DESCRIPTION
fwb_pf is a firewall policy compiler component of Firewall Builder (see fwbuilder(1)). This compiler generates code for OpenBSD Packet Fil-
ter (pf). Compiler reads objects definitions and firewall description from the data file specified with "-f" option and generates pf con-
figuration files and firewall activation script.
All generated files have names that start with the name of the firewall object. Firewall activation script has extension ".fw" and is sim-
ple shell script that flushes current policy, loads new filter and nat rules and then activates pf. PF configuration file name starts with
the name of the firewall object, plus "-pf.conf". NAT configuration file name also starts with the name of the firewall object, plus
"-nat.conf". For example, if firewall object has name "myfirewall", then compiler will create three files: "myfirewall.fw", "myfirewall-
pf.conf", "myfirewall-nat.conf".
The data file and the name of the firewall objects must be specified on the command line. Other command line parameters are optional.
OPTIONS
-f FILE
Specify the name of the data file to be processed.
-o output.fw
Specify output file name
-d wdir
Specify working directory. Compiler creates firewall activation script and PF configuration files in this directory. If this
parameter is missing, then all files will be placed in the current working directory.
-v Be verbose: compiler prints diagnostic messages when it works.
-V Print version number and quit.
-i When this option is present, the last argument on the command line is supposed to be firewall object ID rather than its name
-x Generate debugging information while working. This option is intended for debugging only and may produce lots of cryptic messages.
NOTES
Support for PF has been introduced in version 1.0.1 of Firewall Builder
Supported features:
o both pf.conf and nat.conf files are generated
o negation in policy and NAT rules
o grouping in "from", "to" and ports using '{' '}' syntax
o if checkbox "Scrub" is checked in the rule options dialog, and rule's action is Accept, the compiler generates two (almost) identi-
cal rules: first with action 'scrub' and the second with action 'pass quick'
o stateful inspection in individual rule can be turned off in rule options dialog. By default compiler adds "keep state" or "modulate
state" to each rule with action 'pass'
o rule options dialog provides a choice of icmp or tcp rst replies for rules with action "Reject"
o compiler adds flag "allow-opts" if match on ip options is needed
o compiler can generate rules matching on TCP flags
o compiler can generate script adding ip aliases for NAT rules using addresses that do not belong to any interface of the firewall
o compiler always adds rule "block quick all" at the very bottom of the script to ensure "block all by default" policy even if the
policy is empty.
o Address ranges in both policy and NAT
Features that are not supported (yet)
o custom services
What will not be supported (at least not anytime soon)
o policy routing
URL
Firewall Builder home page is located at the following URL: http://www.fwbuilder.org/
BUGS
Please report bugs using bug tracking system on SourceForge:
http://sourceforge.net/tracker/?group_id=5314&atid=105314
SEE ALSO
fwbuilder(1), fwb_ipt(1), fwb_ipf(1)
FWB
fwb_pf(1)