My laptop has become very sluggish. So I loaded firestarter firewall. It is reporting loads of incoming UDP traffic. I only use this machine for Skype and Firefox based work as most of my stuff is kept on the cloud. Is it safe to stop all this UDP traffic? It would free up my CPU I guess. It seems port 56095 is getting hammered.
View 8 RepliesI am running the latest ubuntu. Sometimes it randomly stops accepting ssh connections, afp/smb connections, and even stops responding to pinging. It is connected via WIFI.
I go over to the desktop and use the browser, and the internet still works fine. Then after a while, it starts accepting incoming traffic again.
I have a ubuntu computer set up as bridge between gateway and lan, with the lan connected to eth0 and gateway on eth1.
I'm trying to get it to basically block everything incoming except for the ports i specify, but also allow outgoing traffic. I've found, tried, modified som examples i found on the web, but still it wont block incoming traffic (ie, im still able to reach my webserver)
These are the rules, and i can't figure out why it wont block:
Code:
#!/bin/bash
iptables -F
iptables -X
iptables -I INPUT -i eth1 -j DROP
[Code].....
I need to configure iptables to block incoming traffic (except specific ports), but allows all outgoing traffic.
I am able to block incoming traffic, but doing so also prevents outgoing traffic (tested by telnet [URL] 80)
The following was used:
iptables -A INPUT -p tcp --dport ssh -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j ACCEPT
iptables -I INPUT 1 -i lo -j ACCEPT
iptables -A INPUT -j DROP
Also, even allowing NOT SYN requests still prevents outgoing traffic.
iptables -I INPUT 1 -p tcp ! --syn -j ACCEPT
Another point:
# modinfo ipt_state
modinfo: could not open /lib/modules/2.6.18-028stab070.14/modules.dep
How to install ipt_state module on ubuntu?
Before explaining the problem, I have to draw the environment. Because of post size limitations, I'll have to break this post in more than one entry.
Physical view
Code:
+--------+ +---+
|storage1|-----| |
+--------+ | s |
| w |
+--------+ | i | +-------+
|router2 |-----| t |-----|router1|--->Internet
+--------+ | c | +-------+
| h |
+--------+ | 8 |
|router3 |-----| |
+--------+ +---+
Device details
[Code]....
assist me in using the iptables firewall to block all incoming mail traffic (SMTP port 25) except that of a certain IP(s)? the situation is that we have a server that we only want to receive mail from a particular sender.
View 1 Replies View RelatedI have set up a Virtual machine on a dedicated server from 1and1. I hoped to use a bridge to give the vm direct access to the internet but 1and1 do mac filtering and so the only option is to use NAT.
I used Virtual Machine Manager on my Ubuntu 10.04 machine at home to install Debain Lenny on the vm on the server using KVM and all went well. I put it on a virtual network 192.168.100.0 and i can access it from the host and i can access the internet from the guest using NAT that libvirt set-up.
I bought another ip address from 1and1 with the hope of forwarding packets to the new ip address 11.22.33.02 to the guest vm.
I have tried all sorts of routing rules using iptables without any success.
my virtual network is on virbr1 the guest ip is 192.168.100.50 my external network device is ip say 11.22.33.01 on eth0 with the secondary ip say 11.22.33.02 on eth0:1
Here are the latest rules i tried:
Quote:
iptables -t nat -A PREROUTING -d 11.22.33.02 -i eth0 -j DNAT --to-destination 192.168.100.50
iptables -t nat -A POSTROUTING -s 192.168.100.50 -o eth0 -j SNAT --to-source 11.22.33.02
iptables -A FORWARD -p tcp -i eth0 -o virbr1 -d 192.168.100.50 -m state --state NEW -j ACCEPT
iptables -A FORWARD -t filter -i eth0 -m state --state ESTABLISHED,RELATED -j ACCEPT
[Code].....
OS : CentOS 5.3 64bit How to trace incoming and outgoing network traffic for a give user? User 'A' logs in to the system and does various network connectivity As root user need to find what are the outgoing and incoming connection that are related with user 'A'. basically need to check the connection flow. netstat will show ESTABLISHED, LISTEN etc.. need something like tcpdump
Eg:- --user option for tcpdump tcpdump -vv -nn -i eth0 host 10.200.2.1 and tcp dst port 8080 --user A Can someone tell me any tool which can do such thing? Even if it can show the process ID of the client application which is trying to establish network connectivity will do.
I have set up an openvpn server on ubuntu via port tcp 443. The server use a public network and almost every ports are blocked (not 443) So when a client connect to the server, if it send traffic needing a blocked port, the connection cannot been etablished of course. So i d like to know if it is possible to redirect all incoming traffic on the server to an other unblocked port (like 443) to bypass firewall.
I dont think openvpn offer this possibility but maybe with linux it is possible..
a good IPTABLES protocol to reject all incoming ssh trafiic except for a single IP or IP range?
View 4 Replies View RelatedI need to set up my centOS computer as a firewall in my home network. Ive got 2 interfaces, eth0 and eth1. I want to allow and forward all traffic on eth0 and block all traffic on eth1 except ssh, ping(icmp) and DNS. How do I do this? Ive tried some editing in /etc/sysconfig/iptables but no luck.
View 1 Replies View RelatedI wanted to tell my server to block all traffic but US only traffic. So i followed this guide:[URL].. Now I know, it's the best way to help prevent hackers/crackers (doesn't matter to me what they are called. I just have to stop them). My server only deals with US clients anyways so might as well just start right there for my server's security before getting into the brute force and injection preventions. So I got it all done compiled everything moved to the proper directory. I then started to setup my iptables. Like so
Code: iptables -F INPUT
iptables -F OUTPUT
iptables -I INPUT 1 -s *.*.*.* -p tcp --dport 22 -j ACCEPT
iptables -I INPUT 2 -s *.*.*.* -p tcp -j ACCEPT
[Code]...
After seeing that i went digging in the code and figured it was something todo with memory allocation.
Recently I notice that when I'm connected to an vpn server (pptpd) and I'm using it as a default gateway my download and upload speed decreases almost to the half of the usual speed. I made a test using iptables in order to count how much GRE packets are generated (except the real traffic itself) in that way:
Code:
iptables -I INPUT -p gre -j ACCEPT
iptables -I OUTPUT -p gre -j ACCEPT
iptables -I FORWARD -s 172.16.10.101 -j ACCEPT
iptables -I FORWARD -d 172.16.10.101 -j ACCEPT
The first 2 rules match all GRE packets between the pptpd server and client, and the next rules - the traffic between the server and the client.
When I turn the counters to zero and begin to generate traffic (to browse, to download etc.) I see that the GRE packets are even more than these in the FORWARD chain.
So, my question is first of all is my test correct and is it true that so much gre traffic is being generated during the browsing (it becames clear that the traffic is double than if the pptpd wasn't used as a gateway) and if yes - can that traffic be reduced?
I'm using Linux Mint 8 KDE, which is essentially kubuntu karmic.
Been trying to set up bittorrent (tried several different apps), have followed all the usual steps, forwarded ports on both Guarddog and my router, but still no incoming connections. Then tried disabling the firewall in Guarddog - still no incoming connections. Never had any problems configuring my router before so can only think that there must be something else blocking ports in linux other than iptables.Also had same problem just using ufw and gufw
I'd like to find some sort of program which can tell me how much incoming data I've had in the last 24 hours. It goes by hours, not by days, but anything that's simple and that can display this will do. Is there any sort of program that does this? Something that would fit well with Ubuntu's style wouldn't hurt, but I'm not that worried about it as long as it does the job.
View 1 Replies View RelatedI have a bunch of Ubuntu boxes on one subnet, 192.168.1.0. I have a Windows 7 box on another subnet, 192.168.2.0. I am able to ping and SSH to all servers on the .1 subnet except for one server, which I will call PITA. I will attempt to SSH to PITA, and it won't respond, nor does it respond to pings. I will the SSH to PITA from another of the test servers, successfully connect, and then when I SSH from my Windows 7 machine I can connect successfully. If I first connect via console to PITA and send some pings out (to anywhere, like 4.2.2.2), I can also connect from my Windows 7 machine. I've never seen anything like this.
One of the weird things is that I used PITA to create an image that I then used to create many of the other test servers, and they work fine, so I'm not sure what the problem is. I've checked /var/log/messages and syslog and there's nothing in them that indicates a problem. I've rebooted this server, restarted SSH, changed the IP in case it was conflicting with something else, forced an ARP update in case it was cached (since I had bonded the interfaces), cleared the ARP cache on my own machine, verified Network Manager is not installed...and I still have this issue.
Here are some network-related config:
/etc/network/interfaces
Quote:
# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).
# The loopback network interface
[code]....
I have a router which makes two ppp connections. PPP0 is my default route and is an uncapped ADSL. PPP1 is a Local Only (South Africa) account which has DNS resolving to its IP. PPP1 allows certain connections in. I want all packets coming in on PPP1 to be marked so that after they have been routed through our local servers they can go back out over PPP1. Both connections use dynamically assigned ip addresses. I want to use PPP0 to make a connection to one of our stores, but when our stores connect to us they will be using PPP1. All packets from these incoming connections will need to be routed back over PPP1.
View 14 Replies View RelatedI have a iptable as firewall, I want to open incoming of port 8080 so I use "# Allow forwarding of incoming Port 8080 traffic" but it didn't work? how can I open just incoming of port 8080?
View 3 Replies View RelatedI'm using postfix on Ubuntu 9.10 and all I need is to occasionally send automated emails from perl or php scripts when data processing errors occur. In other words, I want to reject any connection attempts from remote clients and otherwise allow nothing except outgoing emails from one particular account.f I add this line to the default main.cf, will it do the trick or is it more complicated?
Code:
smtpd_sender_restrictions reject
i'm attemping to re-route incoming traffic of https to one of my servers. (a windows xp with subversion on it)
problem is if i do that ALL https traffic from other pc's is stopped. meaning i can't get any reply from any url with https;
We have something on our network that is reaking havoc with our content filter. I am trying to track it down, but so far I have been unsuccessful. We have approximately 500 devices in 100+ different locations spread across 9 states. Looking at each computer is not really feasible.
I need a machine that can sit in between our network and our internet connection and graphically monitor in real time and logs how much traffic each device is sending and receiving. It would need to sit inline so it has to have two nics and be able to pass traffic. The machine also needs to be transparent. Reconfiguration of our routers or workstations is not an option.
I have used ethereal and wireshark before. Ethereal may be a viable option, but wireshark seems to provide lots of information, but no practical way to make use of it. how to set up the box to be a transparent device on the network that will allow internet bound traffic to flow (freely)?
I suspect the network card but I could be wrong.
Sometimes it doesn't load all of a webpage. In Firefox this results in only some of the page being displayed. In konqueror I get the "Connection to host www.page.invalid is broken" error message. The computer was doing this when running Opensuse 11.3 and continues to do it when running a clean install of Opensuse 11.4. I haven't tried a live CD of Ubuntu or something but that might be worth a go.
I am still new to ubuntu and I use firestarter as my firewall tool and I was told that its just ufw in a gui. Well anyways I noticed a connection to 174.129.241.144 using https and python, I didn't have any scripts running and my browser was closed, I read the man files for ufw and it said to do something like deny from 174.129.0.0/12 and I want to block all incoming and outgoing connections to this IP range and I was wondering how to do that, I heard of iptables that it would be able to do this but I dont know anything about it. What I should learn so I can handle these kinds of situation in the future and how I can block this ip subnet or also what does the /8, /12, and /16 stand for?
View 7 Replies View RelatedPinging out from my netbook (over wifi, to any host) gets ~0% packet loss. Pinging into it (from any host) gets about 50% packet loss.
The router is a Dlink-DIR615 (rev d, running DD-WRT v24-sp2) but all other hosts on it ping eachother fine. I've tried changing routing, disabling IPv6, using older kernels and using wicd, all with no luck. The wireless connections is at 100% most of the time. This could be a new problem with Maverick, but I may not have noticed it before. I believe this is causing web browsing to be really slow and causing SSH timeouts.
I haven't tried madwifi drivers or nsidwrapper yet.
Edit: just booted into Windows and it has the same problem. Could it be a hardware issue? Also tried with a static IP, with no change.
Strangely, a normal ping gets 50% packet loss, but ping -A gets < 1% loss.
Edit 2: no packet loss at all on eth0.
Code:
# uname -a
Linux hulbert-laptop 2.6.35-23-generic #36-Ubuntu SMP Tue Oct 26 17:03:18 UTC 2010 i686 GNU/Linux
Code:
# ifconfig wlan0
wlan0 Link encap:Ethernet HWaddr 00:25:d3:1a:bc:4b
inet addr:192.168.0.102 Bcast:192.168.0.255 Mask:255.255.255.0
inet6 addr: fe80::225:d3ff:fe1a:bc4b/64 Scope:Link
[Code]....
I can launch applications via SSH on a remote wins box. the pid shows up with @:>tasklist. However, for some reason I can not access the app via its web interface after its launched. Also, the process is not showing up in the desktop gui. its like its there but not at the same time...kinda like democracy in the US...Really though, could use some help. do i need to open applications with a " run as" or something like that. I already have the user account szet on the machine.
View 1 Replies View RelatedI've got a box with 2 interfaces, with IP1 = 192.168.100.1 and IP2 = 10.1.1.1 respectively on them. I've got an iptables rule that looks like:
Code:
iptables -t nat -A POSTROUTING -s 192.168.100.0/24 -d 10.0.0.0/8 -p udp -j SNAT --to-source 10.1.1.1 --random
If I get 2 consecutive packets from the same address and port from 192.168.100.0/24, they get SNAT-ed and come out of the same port on 10.1.1.1. If then I get another packet from the same address and port 10 minutes later, then it gets SNAT-ed, but comes out of a different port on 10.1.1.1. My question is: how can I set the time delay I would like iptables to remember its incoming address/port to outgoing port mappings?
I've got a box with 2 interfaces, with IP1 = 192.168.100.1 and IP2 = 10.1.1.1 respectively on them. I've got an iptables rule that looks like:
Code:
iptables -t nat -A POSTROUTING -s 192.168.100.0/24 -d 10.0.0.0/8 -p udp -j SNAT --to-source 10.1.1.1 --random
If I get 2 consecutive packets from the same address and port from 192.168.100.0/24, they get SNAT-ed and come out of the same port on 10.1.1.1. If then I get another packet from the same address and port 10 minutes later, then it gets SNAT-ed, but comes out of a different port on 10.1.1.1. How can I set the time delay I would like iptables to remember its incoming address/port to outgoing port mappings?
I have 2 computers with kubuntu 8.10 using vinagre for my remote desktop viewer and x11nc for my server and I am trying to connect remotely through the command line from one computer to login to the startup screen in the other computer. Is this possible, since it looks like my server does not start until after I log in to my desktop screen?
View 8 Replies View Relatedi need is to have http and https allowed, together with mail server (incoming and outgoing) and ftp, ftps and ssh. all other ports have to be closed.
View 3 Replies View RelatedI have ubuntu server with PPTP on it. I need to limit single connection speed for ip 1 mbit/s, and mounthly traffic limit to 5 GB. How i can do this my task. I try to find somthing with ip tables, but can't find how to creat mounthly limits.PPTP do not have this option, maybe is some other, not hard for configure VPN server? Maybe someone make this task with iptables, and can give commands for limiting? Ofcorse VPN program with integrated accaunts and limits will be better.
View 1 Replies View Related