Security :: Correct/safe Iptables Rules For Redirecting Port 80 To 8080?
Jul 13, 2010
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'm trying to open port 8080 on my application server. I've included it in my iptables; however I still cannot access through ssh nor putty and it doesn't show up when I netstat either.Here is my iptables-config:
-A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT -A INPUT -i lo -j ACCEPT -A INPUT -i eth0 -s xxx.xx.x.0/24 -j ACCEPT
In Lucid I have some ufw rules but I figured that I need to limit the ICMP messages that the box responds to and also limit their number. There are iptables rules to accomplish this but since I already have ufw rules it is safe to use iptables only for ICMP rules ?
i've got a software that uses a specific tcp port e.g 11111. i want to redirect all the traffic from 11111 to squid port 3128. i'm using the following commands to redirecting:
my ubuntu server has two interfaces. eth0 is for local network (dhcp assigns ips) and eth1 is for internet. my ubuntu server acts as a gateway and as an authentication server for users.
at squid also i have the following configuration regarding my port:
acl myport port 11111 http_access allow CONNECT myport. my squid installation is not transparent as users need to authenticate in order to access the web.
my application is a windows application and of course is not working. i examined the packets with wireshark and i noticed that when the program tries to access the internet, squid replies with err_invalid_request (the packet contains that data). the program is trying to send some plain text via port 11111 and as far as i can image, somehow squid declines the data. i cant get rid off squid as i want to pass the traffic from squid. what is the problem?
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.
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.
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.
Other than Firestarter, how safe is it to use an iptables firewall for Linux if you know the basics of iptables but not the details and not exactly what you're doing with iptables? I want to be very secure without configuring iptables myself if possible or doing as little as possible. If you don't think iptables is safe if you don't really know what you're doing, which firewall you can use (Slackware specific, preferably) that is the easiest to install and configure? Are there any that work like free Windows firewalls, other than Firestarter? I've looked around and looked at slackbuild and can't find a Firestarter package, I searched this site also and saw something about the reason there isn't one. I'm concerned with my security and I don't want to write my own iptables firewall - I don't fully know what I'm doing.
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.
Is there any way to verify if packets being trafficked over a certain port are valid for the service you want to use this port for?
One obvious example that probably clarifies my question: When I open port 443 (outgoing or incoming) for https/ssl traffic, I don't want this port to be used for say openvpn traffic. Thus: when someone wants to surf to a website with https, it should be ok but if someone wants to connect to his home openvpn server over that same port, it should be blocked.
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 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?
So I know Linux has iptables, I'm rather new to linux, and I'm wondering, are the stock settings with Ubuntu/Kubuntu safe? Is there anything I need to do make them more secure? I tried adding rules myself for some things but ended up just not being able to do anything so I had to reset back to stock with iptables -F. Should I be safe running as-is?
I've recently installed 10.10 server edition, and I must say it was a pleasant suprise, it's just the way I like it. I use it as a squeezebox-server. But I've run into a problem with the firewall. I did a portscan, which told me there are more ports open then I've told UFW to open. Among which port 25 and 119, when I telnet from another PC to those ports, the connection gets accepted, although there is no answer to any commands (as expected, there's no mail server running). Iptables print-outs also don't mention anything about the respective ports or a daemon that could be responsable, and the same applies to "ps -e" or "ps aux".
Iptables seems to be working, when I remove the rules to allow samba to work, I can't reach the shares, and when I insert them again I can reach the shares. "sudo ufw deny from any" as last rule doesn't change anything either (deny incoming is default (although I never issued the command "ufw status verbose" says it is) so it shouldn't, but ports 25 and 119 shouldn't be open either).
I'm trying to open port 119. I already have a few ports open. I've used webmin to open both incoming and outgoing ports. iptables --list --numeric gives me:
I want to do port mapping on a linux machine using iptables.I have a service listeneing on port 2000 udp and I want to add iptables rule, which will map incoming packets on port 2001 to port 2000, so that service will accept the connections.The idea is that I don't want to change the default port for the service, but to make internal port redirection from (2001 to 2000), so the default service port will be filtered by iptables, and the other port will be open to the outside. The internet host connects to the linux machine on port 2001. The linux machine change destiation port from 2001 to 2000 and the service (on the same machine) process the packets and accepts the connection.I tried adding the following to my iptables rules, but it didn't work out:
I've got two virtual machines running, the first VM (VM1) has two network interfaces, one bridged with my real lan, one a private subnet. The second VM (VM2) has one nic, only on the private subnet.
I have VM1 acting as a router for VM2, giving access to my real lan for internet access. The problem I'm having is I cannot get VM1 to forward ports 80 (http) or 222 (ssh) to VM2 from my real lan.
Here is the script I've cobbled together from various (foreshadowing!) locations:
I would like to allow incoming and outgoing connections when I'm connected to a wired connection, but drop it otherwise. I noticed that ufw can't block outgoing traffic because of will I give iptables a try. I'm unsure if dropping packages that are outgoing will work, the rule after the block rule will allow all outgoing connections.
This what the rules are intended to do, unsure if that is actually the case. Allow all loopback traffic. Allow ping replys Allow incoming on port 12345 if eth0, deny otherwise. Allow outgoing on port 12346 if eth0, deny otherwise.
Code: iptables -A FORWARD -j DROP iptables -A INPUT -i lo -j ACCEPT iptables -A INPUT -p icmp --icmp-type 0 -s -m state --state ESTABLISHED,RELATED -j ACCEPT
I'm using iptables with modules ip_contrack_ftp to be able to use passive ftp. It works well as long as port 21 is being used as listening port. Is there any way to make it work when I configure my ftp server (vsftpd) to listen on an alternative port, lets say 21001 or something? The helper module only seems to be working properly with the standard port, so I was wondering whether there was a way to "tell it" that another port is being used? I mean, of course I make a rule in fw to allow traffic to the alternative port.
But once it's time to start passive connection, then the iptable module cannot handle it properly. I could solve the problem by making a range of passive ports in the ftp-server configuration and allow the incoming traffic to them, but then using helper modules doesn't make any sense. I just want to allow the traffic to the listening port and then want the ip_contrack_ftp module to take care of the rest. This is what I do today - but only port 21 seems to be working. Is there a way to do this with a non-standard ftp port?
