i am learning security and firewalling. i want to know . where a linux firewall is sufficeint and where it is not sufficeint? if you can explain why or give a reference i will be glad. is that security or traffic handling problem? when i should select a cisco product? in tarms of traffic and sceutiry. do you have any good alternative recomendation to Cisco
View 1 RepliesI'm looking for an open source solution to replace Cisco CS-MARS. MARS aggregates syslog data sent to it from remote devices and creates an attack mitigation plan that can then be applied to the devices. It can be used with servers, security appliances and network devices.
I had a brief look at snort, but that seems to function at the packet level and does not aggregate syslog data. Does anyone have experience or maybe know of a product I should look at?
I have been struggling with this for a very long time now. I have installed Fedora Core 9 on my computer. I have set it up as a caching-nameserver and this is working.
Then I wanted to secure my server with iptables, and I have so far made this script:
# Load the connection tracker kernel module
modprobe ip_conntrack
iptables -F
iptables -P INPUT DROP
iptables -P FORWARD DROP
[Code]....
I can reach the dns server with ping. When trying Nslookup it says that it got SERVFAIL from 127.0.0.1 trying next server, and then it times out.
My resolv.conf file lists:
nameserver 127.0.0.1
nameserver DNS-server
Im pulling my hair out trying to get ftp to work through iptables.Im using vsftpd
Table: filter
Chain INPUT (policy DROP)
num target prot opt source destination
1 ACCEPT all -- 0.0.0.0/0 0.0.0.0/0
2 ACCEPT all -- 0.0.0.0/0 0.0.0.0/0 state RELATED,ESTABLISHED
[code].....
What i wanted to do was block everything from getting in my pc but still be able to surf the web and still use instant messenger.
View 2 Replies View RelatedWhen I use system-config-firewall, it asks what interfaces to trust. Where does it store that information for iptables (or whatever uses that info)? How iptables knows at what interfaces to use the rules?There is not that kind of information in /etc/sysconf/iptables and iptables-config.
View 2 Replies View Relatedi've got a few questions about iptables. i know how to set up ip tables to only allow from an ip address or a subnetting ip addresses. question is how do i allow from 2 different networks? would i need to create 2 lines of entry in iptables to the same port? e: allow 10.168.1.1 and 196.168.1.1 on port 22 is there a way to put all that in 1 line or would i need to create to rules for the port? i know i can use the ssh allow or deny but i'd like to stop access even before it gets to the ssh. stop it at the source kinda thing.
View 4 Replies View RelatedWondering if anyone knows what the range specification is meant to do for the colonHAIN at the top of the iptables file? e.g. what is the 1:76 range mean for :OUTPUT ACCEPT [1:76] ?
# Generated by iptables-save v1.4.1.1 on Sat Dec 19 12:28:00 2009
*filter
:INPUT ACCEPT [0:0]
[code]...
I found a behavior of iptables on FC12 to be different and suspect it's broken somehow. Here is what I did
# iptables -F
# iptables -A INPUT -s 127.0.0.1 -p tcp --dport 22 -j ACCEPT
I don't have a shell on FC12 with me to show the output of iptables -L -n but it looks good after above 2 commands. However, after issuing the following third command iptables -L -n gives "wrong" result
# iptables -R INPUT 1 -s 127.0.0.1 -p tcp --dport 22 -j ACCEPT
Namely iptables -L -n gives extra "/0" after 127.0.0.1 in the output I have checked on Ubuntu 9.10 and centos 5.4 and they don't give extra "/0"; iptables is not supposed to do that. Of course, I didn't invent these examples but they are abstracted from actual real life scenerio of trying to build rules on our servers.
i was hoping that someone in here could possibly help me out with my iptables rule set. First here is what i would like iptables to do, i want iptables to deny all packets or traffic from the outside coming in and for output allow the things i need like web and irc etc... Also, i would like iptables to deny access to all services like sendmail and ssh except i would like localhost to have access to everything. What i mean by localhost is that when i run my iptables script it loads fine except when i try ssh from localhost i get this output:ssh -l user localhostssh_exchange_identification: Connection closed by remote hostI know what most of you are thinking, why do i need to ssh into localhost from localhost just open another terminal, well i am getting myself familiar with iptables i want all services logged and blocked but not from localhost. I cant seem to figure out this problem and i have tried several different things. Here is my iptables script, I am hoping that someone out there can tell me what i am doing wrong...
#!/bin/bash
iptables -v -F;
iptables -v -A INPUT -i lo -j ACCEPT;
[code]....
I am using squid on my fedora box as a proxy server.By default the iptables (Firewall) service is on.To allow web pages to my client machines i stop the iptable service.
#service iptables stop
By doing it client computers start browsing.kindly how can I add a rule so that without stoping firewall client compter work fine.my perver IP address is 10.1.80.10
I've got two routers, 10.0.0.0/23 and 192.168.2.0/24, which are joined by a Linux box with interfaces eth0 (10.0.0.2) and ra0 (192.168.2.2). I've got masquerading for ra0, and a route to 192.168.2.0/24 on 10.0.0.0's router. I CAN ping hosts on 192.168.2.0 from 10.0.0.0 just fine, but I CANNOT access web pages.Strangely, If I enable masquerading on eth0, and add a route to 192.168.2.0s router to 10.0.0.0, I can ping AND access web pages from 192.168.2.0Here is my current iptables
Code:
*filter
:INPUT ACCEPT [0:0]
[code]...
i got the new Ubuntu 10.04 and manage to get my cisco aironet wireless adapter 340 series working on my wireless dlink modem , but the problem is when i have the wep security on the modem the cisco wont connect
View 1 Replies View RelatedI use iptables firewall (v1.4.1) installed on FC8. I'm trying to limit the inflow traffic for the port 1723 to certain MAC addresses. To experiment with the mac option, I've written the following iptables rule:
Quote:
iptables -A INPUT -m -mac --mac-source 10:08:08:08:08:10 -j ACCEPT
It didn't work. It gave me this error message:
Quote:
iptables v1.4.1: Couldn't load match `-mac':/usr/local/libexec/xtables/libipt_-mac.so: cannot open shared object file: No such file or directory
Try `iptables -h' or 'iptables --help' for more information. Does that mean the mac module wasn't installed/enabled?
How come FC11 is set by default to reset the IPTables firewall to ACCEPT across the board each restart?
View 4 Replies View RelatedIs linux is a product of REDHAT and all its versions.
View 2 Replies View RelatedThis is for the Linksys AE1000. This may work for other USB wireless network adapters, but I don't know for sure. Here is the original information ( Ubuntu's Forums ) about a very similar card. It clarifies that you need the 'rt3572sta', and some modifications are required to the source from ralink's website to include your Vendor and Product Id. Then modify a few files, and away you go. Step 1) Retrieve your Vendor and Product Id. Easiest way is doing 'sudo tail -f /var/log/messages' and then plugging in your USB device.
Code:
Apr 22 15:35:12 localhost kernel: usb 1-3: new high speed USB device using ehci_hcd and address 20
Apr 22 15:35:12 localhost kernel: usb 1-3: New USB device found, idVendor=13b1, idProduct=002f
Apr 22 15:35:12 localhost kernel: usb 1-3: New USB device strings: Mfr=1, Product=2, SerialNumber=3
Apr 22 15:35:12 localhost kernel: usb 1-3: Product: Linksys AE1000
Apr 22 15:35:12 localhost kernel: usb 1-3: Manufacturer: Linksys
Apr 22 15:35:12 localhost kernel: usb 1-3: configuration #1 chosen from 1 choice
[Code]...
I am unable to restore my iptables from iptables-save after upgrading Fedora. I cannot get iptables-restore to work, and I have resorted to entering rules manually using the GUI.
View 2 Replies View RelatedIPtables creates an error during startup as well as when I try to restart it: Here's the output of:
[Code]....
Since installing F11, my Canon LIDE 50 scanner refuses to work. xsane 0.996 produces an error message: Failed to start scanner: Error during device I/O.
sane-find-scanner says it is there: found USB scanner (vendor=0x04a9 [Canon], product=0x2213 [CanoScan], chip=GL841?) at libusb:001:006 But scanimage -L claims: No scanners were identified.except once when it admitted: device `genesys:libusb:001:006' is a Canon LiDE 35/40/50 flatbed scanner
I reluctantly tested the scanner on a Windoze machine and it works perfectly. And it worked perfectly under F10.
I have a problem with iptables, when I execute
[code]....
I am trying to figure out how I can configure IPtables to only allow VNC traffic to an internal server over SSH.
My configuration is WAN < --- > Gateway (Ubuntu 9.10 Server) < --- > Internal Server (that I want to control with VNC over SSH)
I am using Fedora on my desktop pc. I want to know how can i protact my PC from outside world. What firewall policy should i implement in iptables to keep it more secure.
View 5 Replies View RelatedI'm following an openvpn installtion how to and it says to add this to the iptables:
Quote:
# External Interface for VPN
# VPN Interface
VPNIF="tun0"
VPNNET="172.16.0.0/24"
VPNIP="172.16.0.1"
### OpenVPN
[Code]....
Any thoughts as the whole formatting is separate and has the addition of FORWARD rules, etc. I need the VPN running on the .199 address
i set up a dmz to have a internet web server and ftp server, and ssh only from local network, so i wrote a iptables script to load during boot :
[Code]...
The problem is that everything works fine ( i have the same rules for other services such as samba, nfs, mysql on another server) BUT ftp there is no way to make it work. not even locally.when i try to connect, i log in, but while listing the directory i get MLSD ... and it hangs like this for a moment, then i get error message "connection time out" , "impossible to list directory". if i turn off the iptables script no problem,ftp works fine.. but why all services work and ftp no?
how do i have to modify the rules? what is strange also is that if i set as OUTPUT policy "accept", the server seems to be offline."host unknown" error message. I was thinking the rule INPUT is fine cause at least i can login, but the dir list is not going out, so gotta modify output rules. or state?
I've started a new job and have inherited a couple of RHEL4 64-bit servers. The firewall on them is currently disabled. I'm struggling to get them up and running as iptables is not the most user-friendly application. This lead me to downloading and trying a GUI front-end: Guarddog. Great app! But it doesn't have the default behavior I'm looking for. Here is what I need:
Default behavior: Firewall should be wide open, allowing ALL ports/IP's/TCP/UDP in and out of the server.
Blacklist: Oracle TCP port 1521 needs to be blocked in/out of the server.
This will help get us passed our company's security vulnerability scan. (We aren't able to patch/upgrade Oracle at this time because we'd lose vedor support with a legacy app). I will use these settings as a starting point, and then once I learn more and get more comfortable with iptables (or a GUI app) then I can fine tune things to make them more secure. As far as I know (correct me if I'm wrong) once I get a script I just copy it into /etc/rc.firewall and it will load when iptables starts.
Is this how I would do that?
iptables -A INPUT -p tcp --destination-port 21 -d ! 168.192.1.2 -j DROP
This should block all incoming connections on port 21 from 192.168.1.2, correct? Thus preventing that IP from logging into my FTP.
I'm running fedora 11 and cisco version 4.8.01 (0640). When I connect to my work, and get authenticated, the system freezes completely. In searching it looks like at one point updating the kernel to a new version resolved this, at least for the 64bit implementation. I'm running 32bit and I'm on kernel kernel-PAE-2.6.30.8-64.fc11.i686 which is a newer version then what was listed in the other thread.
View 7 Replies View RelatedDoes anyone experiencing problems with PacketTracer 5.2 in Fedora ? When try to save a project the program crashes with the following error on stderr:
Code:
CPtmpConnection::socketError
callManager : onError
callManager : onDisconnect
Segmentation fault (core dumped)
In /var/log/messages I saw the following error :
Code:
Dec 10 11:03:05 localhost kernel: PacketTracer5[4173]: segfault at 38 ip 00ce4525 sp bffda150 error 4 in libQtXml.so.4.5.3[cca000+43000]
Seems to be a QT4 problem ....
i ran this
Code:
iptables -N rate-limit
iptables -A rate-limit -p tcp -m conntrack --ctstate NEW -m limit --limit 3/min --limit-burst 3 -j RETURN
iptables -A rate-limit -j DROP
iptables -I INPUT 1 -p tcp --dport 22 -j rate-limit
i am no longer able to ssh in to the machine , how can i reset iptables and firestarted back to default?