Security :: Iptables 192.168.1.x Server Can't Ping By 192.168.0.x
Jun 1, 2011
i have set firewall for centos of 192.168.1.21 server like this.
it has a gateway of 192.168.1.2
iptables -P INPUT DROP
iptables -A INPUT --in-interface lo -j ACCEPT
iptables -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
iptables -A INPUT -p tcp --destination-port 22 -m mac --mac-source 00:0F:EB:91:00:01 -j ACCEPT
iptables -A INPUT -p tcp --destination-port 80 -m mac --mac-source 00:0F:EB:91:00:01 -j ACCEPT
the mac source is my laptop's mac address. But when i try to ping from my laptop of 192.168.0.2 (my gateway is 192.168.0.1 but share the same server that has 3 network gateway including gateway for the centos)it failed. what i should do to enable this ping.i also cannot connect to the centos server unless i change my ip to 192.168.1.x and same gateway as centos.can someone suggest what should i modify my firewall to enable connection to centos server from my 192.168.0.2 laptop? is that related to nat and forward chain in firewall of centos?
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
Basically, I have a windows 2003 server virtual machine (vmware) inside Ubuntu 9.10.
The Ubuntu machine has IFconfig: Code: sam@sam-laptop:~$ ifconfig eth0 Link encap:Ethernet HWaddr 00:15:c5:b8:c8:8b UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:0 errors:0 dropped:0 overruns:0 frame:0 TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:0 (0.0 B) TX bytes:0 (0.0 B) Interrupt:17
Why can't I ping or simply access the internal server on my ubuntu machine from a another computer on the 192.168.1.0 (slash)25 physical network? Do I need a bridge? Iptables?
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'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?
I'm trying to limit access to port 8443 on our server to 2 specific IP addresses. For some reason, access is still being allowed even though I drop all packets that aren't from the named IP addresses. The default policy is ACCEPT on the INPUT chain and this is how we want to keep it for various reasons I wont get into here. Here's the output from iptables -vnL
[Code]...
Note the actual IP we are using is masked here with 123.123.123.123. Until I can get everything working properly, we're only allowing access from 1 IP instead of 2. We can add the other one once it all works right. I haven't worked with iptables very much. So I'm quite confused about why packets matching the DROP criteria are still being allowed.
Currently,i use Fedora 10 and get a follow trouble :My network:
route(10.11.10.2/24)----eth0----(10.11.10.105/24)Fedora10(172.16.239.1/24)----vmnet0----(172.16.239.2/24)Virtual Machine XP2. I used : Vmware 6.5.1,Virtual Machine : Window XP SP2.
I was trying to write IPTABLES script to block the ICMP ping using the below mentioned command in OpenSUSE 11.2 Doing this in VMware.....
iptables -A OUTPUT -o eth0 -p icmp -j DROP
& then I tried to ping the different computer & it didnt allow me to ping. Then I deleted using the command -
iptables -D OUTPUT -o eth0 -p icmp -j DROP
then I couldnt ping also. Another thing I found is my firefox is not connecting to the internet as well, but before writing the script, I can connect to internet.
So, I have an Virtual Machine running CentOS 5.4. It sits behind a hardware firewall which also does NAT'ing. I've set up plenty of these, so I know for sure the firewall and NAT rules are set up correctly. From the host, I can ping anything in my subnet and the gateway. But I can't ping anything else beyond the gateway. I can perform DNS queries and when I try to ping, it finds the appropriate IP address.But from the outside, I can ping the PUBLIC address (It's a 1 public to 1 private address NAT, not 1 public to multiple private). I've tried it with IPTABLES on and off, with no change.
I am using an virtual machine. where I need to ping from one machine to another. earlier I was able to ping. But after going to google.com once, I cannot ping back to this machine.
But if I gave ping -I eth1 <IP> then I can ping.
I cannot install any package, so tell me solution which includes not installing any package.
I need to allow ICMP ping for one host only. I found out how to enable it to all hosts (ICMP Filtering, check ping) but I would like to reduce the scope to one host. I know I can add rules in the user_post script but I can't find the correct iptables command ...
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.
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.
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.
eth1 has connection to the net via gateway ..eth0 on the same machine has users on a intranet and needs access to the internet, i need to allow internet connection and prevent packets which logically originate from the internet getting into the intranet
Installing a router, and I need to completely "wipe" iptables (flush I mean) on both computers, and I think I run ufw/gufw on both, so that would need to be uninstalled. The router is very secure, has NAT, etc, etc, and I'd rather setup all that side of things in one point, rather than on each computer.
I new in Linux, I have a Centos5 since sunday and well I have to configure the iptables security of this cpu, I read a lot of examples of iptables in the internet and also another Thread from here but Really a don't know what to do, I saw lots of codes but first of all I don't know where I have to write that and my teacher don't want to help me in this homework. I tried to write the codes in applications --> accessories --> Terminal
