on a fresh Fedora 2.6.35.9-64.fc14.x86_64 installation I have little trouble with chrony. I love that tool for synchronyzing my clock. SELinux complains, that /usr/sbin/chronyd like to read/write to chronyd.pid. Further I find entries in /var/log/messages, that /var/lib/chrony/drift could not be opened. As I'm completely new to SELinux - I'd like to get some help setting the Security Rules. PS: Should the rules be quite fine from the FC-Repo?
I need assistance with my Snort Installation. I used Bodhi Zazen's Network Intrusion Detection System post and found it easier than the previous time I had done it. I am currently running Ubuntu 10.04 server and Snort 2.8.6.1 with BASE 1.4.5. I followed Bodhi Zazen's instructions and when I tested snort it ended with a Fatal Error due to ERROR: /etc/snort/rules/exploit.rules(264) => 'fast_pattern' does not take an argument Fatal Error, Quitting.. Here is the entire output once I ran the test command: snort -c /etc/snort/snort.con -T Running in Test mode
I googled this question, no relevant results. I don't samba, ssh, or any P2P file sharing. Is udp neccesary for general web browsing/file downloading? What would be the best general ufw rules to set for above conditions and varying ip address? I know how to use the full ufw syntax in command line.
I am trying to program iptable rules for implementing a 1:1 NAT which does the following:
1. Forward all traffic from all ports on a public ip to a private ip 2. Forward traffic from a range of ports (x-->y) on a public ip, to a private ip
I did some google searches for the same, and came up with the following.
iptables -A FORWARD -t filter -o eth0 -m state state NEW,ESTABLISHED,RELATED -j ACCEPT iptables -A FORWARD -t filter -i eth0 -m state state ESTABLISHED,RELATED -j ACCEPT
Can someone please let me know strong iptables rules? Below entries are in iptables file.Here Y.Y.Y.Y is another branch public IP.This server acts as gateway+squid server.Further it will serve company's intranet page also using httpd.OS is CentOS 5.0.
I am setting my firewall rules using the command iptables.My question is i wanna know what command i can use that list rule 2 and 3 for instance in my table?i want to create rule that: The host is administered using SSH, scp and sftp so allow incoming SSH traffic and securing remote file copying and transferring.
When 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.
I don't know if FC15 has the iptable rules like the ones shown below by default or not but I wanted a second opinion about the safety they provide. Why is icmp accepted (INPUT rule 1) from/to all ip? and is it better to remove this rule? When the protocol is all (INPUT rule 2), does it mean from ip layer and above?? and is it required/safe to have this rule? The 3rd rule is to allow tcp-port 22 connections (ssh) to/from all ip. I think this is correctly set and required. The 4th rule in INPUT table rejects pings with the icmp-host-prohibited message; which I don't think is the best solution. Instead it can be set to silently drop icmp packets. Then, the FORWARD table uses reject instead of silent drop for forwarding icmp ping packets.
Code:
what do you think about the new rules and their order?
I have a set of iptables rules generated by Firestarter, and i'm in the process of trying to familiarise myself with iptables itself, but there's one particular rule which is confusing me, perhaps somebody could explain it to me
I've configured iptables to act as a stateful firewall, but instead of simply rejecting packets I'd like to waste a potenial hackers time by droping any packet that would otherwise be returned. Are my rules sufficient or have I somehow opened myself up to an attacker by trying to write these rules myself?
I need with some iptables rules. I've done all I can, Googling all over, to cover as many exploits as possible and the following script is what I've come up with. The current set up works and I've checked with NMAP. I just need some sort of confirmation that this is pretty much what I can do.
Code:
LAN="eth0 eth1" RANGE=10.1.0.0/17 WAN=eth2 # Delete all existing rules
[code]....
Also, if I wanted a broadcast to be relayed to all subnets within a defined range, how would such a iptables rule look like? I need this in order to find a networked Canon MP640 printer.
### flush / drop policy sets echo "[+] Flushing existing rules with DEFAULT of DROP [+]" echo "[+] IPv4 [+]" $IPT -F $IPT -F -t nat $IPT -X $IPT -P INPUT DROP $IPT -P OUTPUT DROP $IPT -P FORWARD DROP
echo "[+] IPv6 [+]" $IPT6 -F $IPT6 -F -t nat $IPT6 -X $IPT6 -P INPUT DROP $IPT6 -P OUTPUT DROP $IPT6 -P FORWARD DROP ..... ###OUTPUT rules: LOG rule $IPT -A OUTPUT -o ! lo -j LOG --log-prefix "DROPED OUTBOUND" --log-ip-options --log-tcp-options
I wanted to know how to allow certain applications through the outbound tables. For example, I wish to be able to use tools such as nmap,tracepath, and traceroute. However, I am not sure where to look to understand the ports to open. I was starting to think that maybe rather than ports to open it would need to be somehthing like tcp flags that would ned to be allowed. Any way, I have tried google and am still haing problems. I started wanting to use these tools due to getting ready for my network+ and security+ certs.
I'm trying to set up a firewall at the moment that allows access to my custom SSH port from only my friend's url (they have a static url but dynamic IP). I find iptables a bit of a nightmare and was hoping to use UFW for most of my day to day firewall maintenance and just make a few extra iptable rules to cover exceptional circumstances like this. Fortunately it seems UFW allows this with /etc/ufw/before.rules and /etc/ufw/after.rules. So at the moment I'm just trying to get the basic iptables rules right. As I say I'm not very good with iptables, does this look right?
Code:
## Drop Default SSH port access With Logging iptables -N SSH_DEFAULT iptables -A INPUT -p tcp --dport 22 -m state --state NEW -j SSH_DEFAULT
I have been trying to figure out how to makes rules in iptables that expire after a certain amount of time. From what I have found online you want to use the recent module with --rcheck and --seconds. I have found a few examples and have given them a shot but I can't seem to get it right. Would anyone mind posting an example of a rule that will auto expire?
I've configured squid proxy server in a P4 desktop. I've 50 users in my network. I installed RHEL 4.4 (2.6.9-42 kernel) and the iptables version is 1.2.11-3.1. I've 2 NICs installed in the system. eth0 (192.168.100.99) for local lan and eth1 (192.168.1.2) for outgoing to internet. I've connected DSL broadband modem to eth1 (default ip of DSL modem is 192.168.1.1). All the clients except few has been forced to go through squid by user authentication to access internet. Those clients which were kept away from proxy are 192.168.100.253, 192.168.100.97, 192.168.100.95 and 192.168.100.165. Everything works fine but from last week I observed that one of some notorious user use the direct IPs (192.168.100.97 or 192.168.100.95) in the absense of the owner of these IPs to gain access to internet as we applied download/upload restrictions in squid.
I want to filter the packets of source hosts using MAC address in PREROUTING chain. I read somewhere that IPT_MAC module must be installed to make this happen. So that those notorious users can not change their ips to gain direct access to internet.
Below are the contents of my iptables file (I've ommited few entries for safty purpose).
# Generated by iptables-save v1.2.11 on Wed Nov 25 16:35:57 2009 *filter :INPUT ACCEPT [14274:3846787] :FORWARD ACCEPT [4460:1241297] :OUTPUT ACCEPT [16825:4872475] code....
I was wondering if there is a way to find out IP blocks based on a given region. I know there are IP Lookups that will tell you what Country and possibly City a given IP is from. What I want is the following:
- I would like to set up a IPTABLES rule that implements something like:
=> ALLOW VPN connections FROM THIS ISP/IP BLOCKS THAT ARE IN CITY XYZ
Basically, I want to limit my incoming VPN connections FROM my ISP in the surrounding area. So, for example, I can go to my friends house who also has the same ISP. I should be able to connect from his home to mine because we have 1) same ISP 2) IP blocks is confined to a particular local location.
my ufw rules have been loaded and active yet using iptraf i see tcp connections on ports that were never allowed by ufw. can anyone explain this too me does ufw just not work?
When I upgraded to 10.4LT I agreed to something that stopped snort, after days decided to just re-do with new snort version. Used bodhi.zazen's MySql instruction version (which is what I used in the past) Everything went pretty well except for figuring out that I needed to delete all the lib_sfdynamic_preprocessor_example?? files (I also deleted all the lib_sfdynamic_example?? files too just to be safe). Used my original Oinkmaster with updated rules version and downloaded the emerging threats too (as I had in the past) and snort won't run with some of the emerging threat rules because it's lookning for snortsam (fwsam). I read up and snortsam looks like a good idea (if I'm wrong somebody just let me know)
if this seems dumb, but I really don't understand, the snortsam directions are HORRIBLE, the snortsam src looks like a windows file when unpacked with all the .dll files(but they say for all OS's), it builds but you need to copy the binary to /usr/local/bin (what in ubuntu would be a binary?).
the snortsam-patch-2.8.tar.gz won't unpack and the Snort 2.8.6 patch is a file, not a package (have no clue where to put it or what to call it if I got the 2.8.tar.gz to unpack so I could build it)
I recently set up a ftp server in my house running a dyndns service so I can get to it from the outside. I called my isp to get some help in setting up the router to forward port 21 from the outside to that box, and in short we had some problems. Long story short, they ended up bypassing the router itself, and now the line running to the box is its own fixed external ip. Naturally I want a pretty darn good iptables setup for this. The box runs proftpd and so far my iptables only accepts local loopback and port-21. (I left port 80 closed as its only purpose is to be a standalone ftp server) But I know there must be a safer rule for port 21, as right now its just wide open. Anyone have any ideas on how to make this a bit safer? Also would that command be fine for any of the linux machines im connecting to it from the outside too?
I am trying to lock down a server using audit.rules. I intend to use ausearch to review certain entries from time to time. I noticed that it's possible to assign a "key" to each rule and then use `ausearch -k` to show only the records that have that key.Unfortunately, the key feature seems broken. I started with the following rule in audit.rules:
Code: -a always,exit -F arch=b64 -S open -S openat -F exit=-EACCES -k deny I do a `cat /etc/shadow` and a `ausearch -ts today -k deny` and it seems all went well.
I have setup my linux fedora server and i want to restrict access to my server.Basically i control using iptables.I'm not sure how to write an iptables rules to control drop all connection to port 8080 and allow only certain ip can access the instance on port 8080 example ip=10.254.14.16,192.168.1.10.
I've read the instruction about setting up the iptables rules to filter all port except HTTP, SSH, FTP. I require first remove all default iptables rules and set default rules to all chains as DROP: # Set default-deny policies for all three default chains $IPTABLES -P INPUT DROP $IPTABLES -P FORWARD DROP $IPTABLES -P OUTPUT DROP
Then allow only some ports: #Accept inbound packets that are part of previously-OK'ed sessions $IPTABLES -A INPUT -j ACCEPT -m state --state ESTABLISHED,RELATED # Accept inbound packets which initiate SSH sessions $IPTABLES -A INPUT -p tcp -j ACCEPT --dport 22 -m state --state NEW # Accept inbound packets which initiate FTP sessions $IPTABLES -A INPUT -p tcp -j ACCEPT --dport 21 -m state --state NEW # Accept inbound packets which initiate HTTP sessions $IPTABLES -A INPUT -p tcp -j ACCEPT --dport 80 -m state --state NEW # Log anything not accepted above $IPTABLES -A INPUT -j LOG --log-prefix "Dropped by default:"
But I hired a VPS from other country so the only mean I can manage it is via SSH. If I setup the default rule to DROP first, I afraid that I can no longer connect via SSH to tell iptables allow SSH So my question is: - Does the IP tables take effect immediately after I input a rule? - Is there any mean to run this as a batch job (create a script and run all these rules one time). - My VPS has a web control panel which have a terminal via web. Is this a native terminal or just a connection via port 80 or 22?
I'm using RHEL 5 with the Enhanced Security. Using the suggest NISPOM Red Hat documented settings (located on the system; copy - paste) I have managed to audit failed file open accesses however, this setting only retained if I enter it at the command line (/sbin/auditctl -a ). If I reboot the system or restart the service all my -a (not -w) located in the /etc/audit/audit.rules are not retained.
I am setting up tomcat server on my Centos 5.5 machine. I've been advised to run tomcat on 8080 as non root user and redirect traffic to it from port 80.
I searched and found the following iptables commands for this:# iptables -t nat -A PREROUTING -p tcp --dport 80 -j REDIRECT -to-ports 8080 # iptables -I INPUT -p tcp --dport 8080 -j ACCEPTI have a doubt:
Tomcat is not accessible via port 80 without the second command. But the second command opens 8080 and makes it accessible over the internet (tomcat is accesible via both: www.<website>.com and http://<ip address>:8080). This doesn't seem right. Is there some simple (iptables) way to redirect traffic "internally" from port 80 to 8080 without having to open 8080 to the internet.
I want to simplify some of my rules, so I want to create rules for certain services like xmpp, web, etc. since some of them use multiple ports, and I toggle them on/off a lot. Can I simply put the jump to rule clauses in the Input chain, and once the sub chains run, does it return to the input chain after the jump to rule clause? I want to do this so I don't have a ton of rules in the input chain. I think that if I simply make a list of all the rules to jump to in the input chain, it will work itself through all of them until it finds a matching filter in one of them correct?