CentOS 5 :: System Hangs During Boot - "Applying Iptables Firewall Rules"
Jan 8, 2010
I am booting centos 5.4 on machine. The system hangs at line "Applying iptables firewall rules".Is there any way to skip starting iptables service during boot or disable it during boot so the system finally reboots.
I just install 1 firewall using Iptables. Firewall includes 2 NIC: NIC1 <IP PUBLIC> NIC2 192.168.10.1 I installed 1 web server IP: 192.168.10.2 I have some PC IP range: 192.168.10.10->20
I set rules NAT on firewall and PC & web server can connect internet good, but I have problems: When PC access to web server with IP 192.168.10.2 that ok, but PC can't access to web server when using IP Public. But outside internet, I can access to web server using IP Public.
Rules on IPTables Code: # Generated by iptables-save v1.3.5 on Sun Mar 7 21:01:16 2010 *nat :PREROUTING ACCEPT [950:126970] :POSTROUTING ACCEPT [89:5880] :OUTPUT ACCEPT [19:1342] -A PREROUTING -d 209.99.242.124 -i eth0 -p tcp -m tcp --dport 80 -j DNAT --to-destination 192.168.10.2:80 -A POSTROUTING -s 192.168.10.0/24 -o eth0 -j SNAT --to-source 209.99.242.124 *filter :INPUT DROP [1599:157409] :FORWARD DROP [0:0] :OUTPUT ACCEPT [232:34452] -A FORWARD -i eth0 -o eth1 -m state --state RELATED,ESTABLISHED -j ACCEPT -A FORWARD -i eth1 -o eth0 -j ACCEPT -A FORWARD -i eth0 -o eth1 -d 192.168.10.2 -p tcp --dport 80 -j ACCEPT -A INPUT -i lo -j ACCEPT -A INPUT -i eth1 -j ACCEPT -A OUTPUT -o lo -j ACCEPT -A OUTPUT -o eth1 -j ACCEPT COMMIT
I have been trying for days now to get this to work. didn't want to bother people with my questions, i have installed Fail2Ban 0.8.4 on CentOS 5.4.
I get the email notifications from Fail2Ban stating that it just blocked another IP, however, when i look at the iptables through webmin, nothing is actually in there, also the log/secure file dose not show that the ip has been blocked.
Even when I try to log-in with the wrong password, after a few tries i get the email telling me that my ip is blocked, however, I can still SSH using my 'blocked' IP.
I am trying solve a strange problem which ocurred after upgrading many packages including kernel and iptables.This is a Fedora 10 PC acting as a small home-server I've been using over a year without problems. Recently, I've run a yum upgrade and after that, connections outside home wouldn't work. No changes in IPtables (firewall) rules have been done. But connection through local network is working.Symptom is.I've connected to my second PC at home and connected to the server. It works fine on local network. I restart network services (service network restart) and outside connections could be established.I have disabled iptables and ip6tables and after reboots it works fine. But PC is running without firewall.
I have a clean install of Ubuntu server Lucid Lynx with the virt-host task installed. I need to find the location of the iptables rules that are being loaded when the system boots. These are the rules for the virbr0 interface.
Is it possible to apply a rule to a specific local IP? For example lets say I have a two IP's assigned to my server, 1.1.1.1 and 2.2.2.2.;.I want to deny all connections going to 1.1.1.1 only asides from a couple of trusted IP's I will define.
CentOS 5 iptables 1.4.1.1 APF 9.7 Webmin 1.4.80 (yes i can be a gui noob at times)
I'm currently running a dedicated server that hosts a couple of sites and runs a game server or two. I was using iptables on its own for a while, but recently I'm a target of all sorts of attacks (typically aimed directly at the gameserver on port 7777. UDP flood attacks, etc). I'm also seeing an spike in foreign spam, SSH brutes, and a few people in Turkey thought it would be cute to download files over and over and over I have decided to start banning entire countries, using the subnets listed here [URL]... I'm trying to block Central and South america (189,190,200,201.x.x.x), China, Ukraine, Turkey, Iran, Spain and Italy. I do this because a majority of the traffic from those areas are usually up to no good.
I installed APF so I could easily add these ranges in deny_hosts.rules and be done with it. I added the ranges, which turned out to be too many, and the system tanked. I decreased the amount of ranges to just 4:
189.0.0.0/8 190.0.0.0/8 200.0.0.0/8 201.0.0.0/8
Restarted APF and it loaded fine. Do an apf --list and iptables --list and it shows those 4 ranges as blocked. The only issue...I have people from 190.x and 200.x connecting to the gameserver and PLAYING. Its as if the firewall isnt there. Also, adding those ranges to /etc/hosts.deny (or whatever) doesn't block them either.
I add one of my own ips and I get blocked instantly. WTF?? I look in the iptables for webmin, and it shows an empty firewall. I do iptables --list and it shows the ranges I added in APF. I'm looking at building (or whatever its called) an fresh iptables with the geoip module added in. [URL]...
I've never done anything like this, and I don't want to kill the box. I also don't want to spend the effort if 1) something is wrong with my system to begin with and 2) the geoip module doesn't work. geoip module aside....how exactly should i configure the firewall? Empty iptables completely and then rely on APF for everything? Oh and heres another tidbit: I tried this before 2 years ago and it used to be that anything I put in APF would show when i looked at iptables using the webmin module. Thats no longer the case now. That was also on CentOS 4 when it did that. I don't know if moving to 5 is whats preventing it now.
In a nutshell, I'm new at this and I'm being inundated with terrible people trying to do terrible things and I'm ready to just give up. Can someone just give me a quick rundown on:
1) how to test that my firewall is actually firewalling
2) how I should configure the/a firewall on this CentOS5. Not too specific, I just want to know if I should empty iptables then load apf, should i not bother with APF (i like it when it works), is there a specific order of doing things?
I am facing a strange problem witht my iptables as there are some firewall entries stored somewhere which is displaying the below firewall entries even after flushing the iptables & when I restart the iptables service then the firewall entries are again shown in my iptables as shown below,
I am booting centos 5.3 on x86-64 machine. The system hands at line "Starting xend:". Is there any way to skip starting xend service during boot or disable it during boot so the system finally reboots.
Even though I've set up HTTPS to be trusted, it still blocks my school's https site: "mnsu.edu/eservices" same with SAMBA and SSH.
If enter the GUI and authenticate as root, change anything and apply, then exit: it works fine and so does SAMBA. However, after restarting, everything stops working again.
yet secure firewall configuration that doesn't require any login or headaches.
can I deny the access to my server for a specific OS? I have one PC which I want to give it acces from winxp, but if it's boot into ubuntu I want to deny all access to my server, same IP, same ethernet card
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
every now and then Firewall Builder fails to open rules (*.fwb)and I have to use some old backup. it does load 'object libraries' but the main 'currently editing policy' panel is empty.(in gnome, debian testing amd64)
I added a few rules to my /etc/iptables.rules file and then used sudo iptables-restore < /etc/iptables.rules but i got an error saying "iptables-restore: line 29 failed".But the only word on that 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.
Consolidate several lines of a CSV file with firewall rules, in order to parse them easier?
I have a .csv file, which I created using an HTML export from a Check Point firewall. The objective is to have all the firewall configuration lines where a given host is present. I have to do this for a few hundred, manually is not a reasonable option. I'm going to write a simple Python script for this.
The problem is that the output from the Check Point firewall is complicated to work with. If a firewall rule works with several source or destination hosts, services or other configurations, instead of having them separated with a symbol other than a comma, I get a new line.
This prevents me from exporting the line where the host is present, since I would be missing info.
Let me show you an example, hostnames are modified, of course:
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 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 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.