Ubuntu Security :: Block All Ports Except Pop And Smtp In NAT Through Iptables?
Jan 20, 2010how to block all ports except pop,pop3,smtp in nat using iptables in squid on redhat A3
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OpenSUSE Network :: Block All Ports But Port 80 With Iptables (DMZ)?
Jun 25, 2010I have a Suse 10.3 router with 4 network cards. 1 is to connect to the big network and thereby also the internet, 2 are for 'client' subnets and I want to use the last one as a DMZ. In this DMZ will be a web server which has to be accessible from the other 2 subnets and from the big network. I could do it with a few simple clicks in Yast firewall, but I have some issues with this firewall and there for I want to use it as minimal as possible, using Iptables.
So now I'm struggling a bit with Iptables. Basicly what I'm looking for is how to block all ports but 80 in this last subnet with iptables.
General :: Block All Ports Except SSH / HTTP In Ipchains And Iptables?
Jun 15, 2010How can I block all ports except
ssh (port 22)
httpd (port 80)
using iptables and iphains?
Ubuntu Security :: Iptables How To Filter SMTP W/o S/MIME
Jul 10, 2011Does anyone know the iptables statement that will block inbound SMTP messages that are NOT S/MIME encrypted?
View 1 Replies View RelatedSecurity :: UFW Block On Legitimate Ports
Jun 30, 2010I enabled ufw yesterday, and am finding log entries like:
Jun 30 13:07:51 xxxx kernel: [15702368.296557] [UFW BLOCK] IN=eth1 OUT= MAC=00:22:19:5e:8f:23:00:0c:db:fc:8b:00:08:00 SRC=xx.xx.xx.xx DST=xx.xx.xx.xx LEN=40 TOS=0x00 PREC=0x00 TTL=55 ID=47632 PROTO=TCP SPT=58875 DPT=80 WINDOW=65535 RES=0x00 ACK FIN URGP=0
What is puzzling is I did the command: ufw allow 80.
Ubuntu Security :: Delete Builtin Ufw Rules / Block The FTP Ports?
May 6, 2011How do you delete ufw rules which you didn't make?
I want to block the FTP ports (20 & 21) but even if I put in DENY rules, it appears that these rules are letting traffic through
Code:
9 400 ACCEPT tcp -- * * 0.0.0.0/0 0.0.0.0/0 tcp dpt:20
0 0 ACCEPT tcp -- * * 0.0.0.0/0 0.0.0.0/0 multiport dports 21,20 state RELATED,ESTABLISHED
0 0 ACCEPT udp -- * * 0.0.0.0/0 0.0.0.0/0 multiport dports 21,20 state RELATED,ESTABLISHED
How do I delete these rules? I've tried.
Code:
sudo ufw delete allow 20
sudo ufw delete proto tcp from any to any 20
but I get "Could not delete non-existent rule".
Since I didn't make those rules I have no idea what OpenBSD's PF syntax (what ufw uses) is for them.
Security :: Anyway To NOT Log Dropped Ports 137 / 138 In Iptables?
Mar 30, 2011We do NOT support samba on our Unbuntu servers but still zillions of windows machines are constantly trying to connect on the SMB ports. I've added a rule that drops access to destination ports 137-138 and that seems to work. But it creates many many log entries documenting that the packet has been dropped. I've been researching and cannot come up with a way to suppress logging for these drops.
View 4 Replies View RelatedSecurity :: Iptables To Block Ip From Ftp?
Mar 6, 2010Is 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.
Fedora Security :: Iptables - Block Everything From Getting In My Pc
Mar 17, 2009What 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 RelatedUbuntu Security :: Iptables, Block Port Except For Eth0
May 24, 2011I 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
[Code]....
Security :: Iptables - Block Bad And Not Related Packets
Jun 8, 2011My VPS host a mail, blog and web site. So i want to block port i not use. The port that i use is 80,21,2022,443. The other port will be drop. I want to block bad packet and all packet that not related. Can anyone how to write in iptables?
View 2 Replies View RelatedSecurity :: Block IP After Failed Login Attempt Using Iptables?
Aug 11, 2009I keep getting hundreds of SSH failed logins per day. Is there a way with iptables, i can say if a user connects too to port 22 over 8 times in 10 minuntes, then block them for an hour?
View 7 Replies View RelatedGeneral :: Unlocking POP And SMTP Ports?
May 31, 2010M using Ubuntu. How do i unlock POP and SMTP ports.
View 1 Replies View RelatedGeneral :: Block FTP And SMTP Service?
Sep 8, 2010i would like to block FTP and SMTP service as a part of linux server hardening.
View 14 Replies View RelatedUbuntu Networking :: How To Block Ports
Dec 16, 2010I was following the directions over on the page How to watch Hulu overseas without a proxy server and got to the section about blocking ports, which I need to block port 1935. I figured this would be easy, as the mac instructions are
Code:
sudo ipfw add 0 deny tcp from any to any 1935
sudo ipfw add 0 deny udp from any to any 1935
and the Windows instructions are practically a book in itself. Since this page was lacking instructions on how to do it in Ubuntu, and ipfw seemingly doesn't exist in Ubuntu, how do I block the ports
Networking :: Cant Open Any Ports In Iptables?
May 14, 2009Since there was no response on my other post which i spent about a hour writing, ill go for something simpler. I run this on my server
Code:
# set default policy for the NAT table
iptables -t nat -P PREROUTING ACCEPT
[code]...
Networking :: Forwarding Ports With Iptables?
Dec 23, 2010I am running a server with ssh and a vpn server set up. It is behind a debian router with a firewall which uses iptables. i have it set up to forward ports 22 and 443 to ssh on a computer within the LAN(so when on a restricted network i can still ssh into my network) and forward anything to 1723(for my vpn) to that box also. However, the only port that gets successfully forwarded is port 22. The other two appear closed. here is what the script looks like:
Code:
#!/bin/sh
#
[code]...
Ubuntu Servers :: Iptables Allow Ports To A Specific Ip Or Domain Name?
Jul 23, 2010How to configure iptables to allow only 22,80,3306 ports for only a dynamic public ip/dyn dns domain name on a ubuntu server?
View 9 Replies View RelatedUbuntu Networking :: Set Any Ports On Iptables For One Specific Host Only?
Feb 15, 2011I like to set in iptables to allow access from one host to my server on any ports.Currently the iptables have been configured to deny all and to allow access only to those I've specified.
View 2 Replies View RelatedFedora Networking :: Iptables On Bridge Ports?
Apr 21, 2011I'd like to pass all traffic between bridge ports via the FORWARDING chain, so I changed following sysctl parameters:
Code:
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
[code]...
Networking :: Set Any Ports On Iptables For One Specific Host Only?
Feb 16, 2011I like to set in iptables to allow access from one host to my server on any ports.
Currently the iptables have been configured to deny all and to allow access only to those I've specified.
Can anyone advice on the command to achieve this?
Networking :: Iptables - Portforward To External IP And Ports?
Jun 30, 2011I want to portforward client connections from an ubuntu lts server to another external server. btw i am a noob on iptables. i have tryed using the basic commands for iptables with no success. For example:iptables -A PREROUTING -t nat -i eth1 -p tcp --dport 7878 -j DNAT --to 91.23.45.67:7878iptables -A FORWARD -p tcp -i eth1 -o eth0 -d 91.23.45.67 --dport 7878 -j ACCEPTso basically i just want a rediraction for from one ip to another. Example: A client tries to connect to ip 123.45.67.89 on port 7878 and the server forwards him to ip xx.xx.xx.xx on port 7878, meaning that xx.xx.xx.xx is the actual server with services. Server with ip 123.45.67.89 is only forwarding the client to external ip... how can this be done in a simple command?
View 7 Replies View RelatedSoftware :: Configure IPTABLES To Allow Certain IP Ranges To Ports 25 And 465?
Feb 16, 2011I have a mail server with IPTABLES enabled.I want to allow access to:
41.0.0.0/8
58.0.0.0/8
61.0.0.0/8
[code]....
Software :: Open Ports Using Iptables From Shell?
Sep 18, 2009I am trying to open VNC ports(5901,5902) on my RHLinux machine using iptables. I am able to do it from GUI system-config-security. Go to the Administration > Security Level and Firewall, then select "other ports" at the bottom and enter the portNum 5901 to open and select tcp, then click OK and OK again to save your settings. From my windows m/n iam able to open vncsession using vncviewer on 5901 port.But when I am trying to do it from command line:#iptables -A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp --dport 5901 -j ACCEPTThis command added the entry in /etc/sysconfig/iptables and listed in iptables -L command.Then I saved and restarted the iptables.#service iptables save
#service iptables restartWhen I am trying to open the VNC session from vncviewer, it is giving me error and session not opened.Is there some thing I missed here? where can I check the logs for this? I definetly need
Ubuntu :: How To Block All Outgoing With IPTables
May 10, 2010I want to block all outgoing traffic with iptables and only allow a few specific websites. I would like to get the code to do so and also to revert the changes in case I want to unblock them.
View 1 Replies View RelatedNetworking :: Configuring Iptables To Locally Translate Some Ports?
Apr 27, 2011Because my ISP is blocking every IP port under 1000, I'd like my local nat'ed server to be able to translate incoming and outgoing traffic from some port above 1000 to the default server port locally.Example :
To connect to my IMAP server (default port : 143) from the outside,I'd connect to my public IP, port 1143 (opened and nat'ed to the right server on my router) and the server would translate this port to 143 on the same machine.I wish I could simply configure my router to do that but sadly Linksys doesn't permit such setting... I also could modify the listening port of my server but I prefear to keep the default port inside my network.I think that iptables is the right tool to do that and I never used it and I must say that this tool is not so easy to configure at first sigh
General :: Block Some Ipaddres In Iptables (Ubuntu)?
Aug 3, 2010Currently I have 2 Lan card in My System one for communicate client pcs (Lan card Ip 192.168.1.100) and other for Internet (Lan card ip 192.168.0.100.) All client pcs are in 192.168.1.0 Subnet Here i implement my system as router through iptables all clients are communicate through only 192.168.1.100 (clients default gateway also 192.168.1.100) Now no problem for forward rules when my system is active all clients are get internet.
Output of iptables -L
Chain INPUT (policy ACCEPT)
target prot opt source destination
[code]....
Now i want to block some ip address and port ways i tried lot of things in internet when i type iptables -A INPUT -s 192.168.1.150 -j REJECT (i found in internet it will block that ip address for getting internet and any access through my sys)
Now th Output
Chain INPUT (policy ACCEPT)
target prot opt source destination
REJECT all -- 192.168.1.112 anywhere reject-with icmp-port-unreachable
[code]....
it will block icmp protocol only I want to know how block ipaddress and port address ways...
General :: Block UDP Protocols In Iptables - Ubuntu ?
Aug 5, 2010Currently I have 2 Lan card in My System one for communicate client pcs (Lan card Ip 192.168.1.100) and other for Internet (Lan card ip 192.168.0.100.) All client pcs are in 192.168.1.0 Subnet
Here i implement my system as router through iptables all clients are communicate through only 192.168.1.100 (clients default gateway also 192.168.1.100) Now no problem for forward rules when my system is active all clients are get internet.
Now i have problem with blocking UDP protocols i tried lot of things in net iptables -A INPUT -s 192.168.1.0/255.255.255.0 -p UDP -j DROP
But it's not blocking UDP protocols (i change UDP to ICMP Protocols then icmp is blocked every ip address)
General :: Transparent Squid - Iptables Syntax And Unable To Use Outlook To Access SMTP And POP3
Feb 10, 2011I've set up Ubuntu 9.04 (desktop) at home in a lab environment (workgroup rather than domain) and have configured Squid. Everything works fine but, when I took it to the next level and made the proxy transparent, my problems began. I can still access sites (having pointed the XP Pro client to the squid box as the DG) and the sites are logged in /var/log/squid/access.log but I am unable to use Outlook to access my SMTP and POP3. I guess that the setup is blocking ports 25 and 110 and I'll need to configure iptables to forward packets destined for these ports directly to the "real" DG, rather than the Squid box. Here's the set up:
A single NIC (eth0) on 172.19.0.250 / 16 (static) ADSL router ("real" DG) on 172.19.0.1 I executed iptables -t nat -A PREROUTING -i eth0 -p tcp --dport 80 -j REDIRECT --to-port 3128 My squid.conf:
Code:
acl all src all
acl manager proto cache_object
acl localhost src 127.0.0.1/32
acl to_localhost dst 127.0.0.0/8
acl localnet src 10.0.0.0/8# RFC1918 possible internal network
acl localnet src 172.16.0.0/12# RFC1918 possible internal network
acl mynet src 172.19.0.0/16
[Code]....
Networking :: SQUID Intercept IPtables - Whitelisting Ports And Sites
Jul 6, 2011I'm having some issues settings up a transparent proxy server, which should allow only regular web browsing (port 80), any other port (including HTTPS (443)) has to be blocked, as well as any other port. Right now, I'm using Debian 6 and Squid3. The server only has one NIC. The topology is like this:
Clients <-> Proxy Server + DHCP Server <-> Internet
With this setup, the network does have internet access and the websites I whitelisted are the only ones accesible via browser, however port block is not working, every port is open, hence why trying to access blacklisted websites through HTTPS is possible. Seems to me Squid3 is doing it's job fine, however IPTABLES for some reason seems to be redirecting all the trafic to port 3128 (Squid3 port). I could be wrong, but I've been unable to do anything related to ports with squid3 (either whitelisting or blacklisting).
For Iptables I used:
Code:
iptables -A PREROUTING -t nat -i eth0 -p tcp -j REDIRECT --dport 80 --to-port 3128
iptables -A INPUT -i eth0 -m tcp -p tcp --dport 80 -j ACCEPT
iptables -A INPUT -i eth0 -m tcp -p tcp --dport 22 -j ACCEPT
iptables -A INPUT -i eth0 -m tcp -p tcp --dport 3128 -j ACCEPT
iptables -A INPUT -i eth0 -m tcp -p tcp --dport 443 -j DROP
Squid3 config:
Code:
acl manager proto cache_object
acl localhost src 127.0.0.1/32 ::1
acl to_localhost dst 127.0.0.0/8 0.0.0.0/32 ::1
acl Safe_ports port 80 # http
acl whitelist dstdomain "/etc/squid3/whitelist"
acl CONNECT method CONNECT
http_access allow manager localhost
http_access deny manager
http_access deny !Safe_ports
http_access deny !whitelist
http_access allow localhost
http_access allow all
http_port 3128 intercept
hierarchy_stoplist cgi-bin