I've got a Slackware 12.2 system that I'm trying to get to accept traffic on a given port, let's say 34521. When I use canyouseeme.org, to see if that port is responding, it is not.
I've put in an iptables entry to accept traffic on that port, is there anything else I need to do?
Our DBA has an application running on Server2 which needs to connect to Server1 (Linux OEL5.5 server) thru port# 9171. I use telnet to test basic connectivity.What should I do on Server1 in order to open up port#9171 for connection.
View 4 Replies View RelatedI have "Server A" with real internet ip 1.2.3.4 (eth0) and lan ip 192.168.1.1 (eth1) There's also "Server B" with lan ip 192.168.1.2 (eth0), I'm running an Apache Web server on "Server B", so I want to redirect all traffic from IP 1.2.3.4 port 80 (Server A) to 192.168.1.2 port 80 (Server B), using the following rule:
[Code]....
iptables -t nat -A PREROUTING -p tcp -d 1.2.3.4 --dport 80 -j DNAT --to 192.168.1.2:80 This actually works pretty good, from internet I can browse ttp://1.2.3.4 But the problem is that if I check the Apache logs, all incoming connections seems to come from 192.168.1.1 instead of showing the real source ip addresses (internet ip's) so this is screwing up all my web stats, I've been looking for hours and hours on how to make a transparent redirect, but can't find any info, I know there must be a way because my old WRT54G router which uses iptables could do it.
I'm new to iptable configuration. I've set up a VPN using DD-WRT on my router and it works fine. However the VPN company does not allow port 25 traffic (in case of spammers) so now I can't get my emails sent out.
I'm guessing I can add some rules to my iptable so that all traffic except port 25 traffic can go out through the VPN tunnel. And hopefully, all port 25 traffic will go out through the normal Internet connection.code...
made software which we can get network traffic Report of of Switches for Daily,monthly and yearly base , in MRTG we can configure as a switch so we can get particular switch Traffic but how can we get each port of traffic of a switch in MRTG
View 1 Replies View RelatedI have problem with port based routing for local traffic. I can't use trick with iptables -t mangle, ip route table 1, ip rule fwmark table 1 because it works only with forwarded packets. I can't even use patch-o-matic because it's obsolete. And xtables-addons doesn't contain support for "-j ROUTE" yet.
View 2 Replies View RelatedI have an log monitoring application that is listening on port 514 to receive events only from certain hosts.In order to control this,I've tried set up iptables to define those hosts that are allowed to this application. Here is an example of the script that contain the commands:
iptables.sh -> Code: iptables -I INPUT -p tcp -s 192.168.0.10/24 --dport 514 -j ACCEPT
iptables -I INPUT -p tcp -s 192.168.0.15/24 --dport 514 -j ACCEPT
...
[code]....
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 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've a server, and I want to drop all the traffic going out with other source port than 80 (apache) and 22(ssh). The reason is I want to prevent my machine sending packets I don't know (i.e. my server scanning networks or making DDOS attacks without my knowledge). The problem are the updates. If I do what I've said, the updates will not work. I want to allow updates, so I need to let DNS traffic (port 53) and the traffic of the updates to go out.
The problem is the source port. This traffic uses a dynamic port (I think like HTTP). Is there any way to specify a source port to do this? If a have a static port to do this, I would drop all the traffic going out with other port than 22,53,80 and this port.
I 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.
Is there a graphic tool that can monitor the traffic over a USB port?
ie like system monitor for network traffic but over a specific port?
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 am trying to list all traffic from 1 IP address but filter out port 1057.I keep getting syntax errors. I've tried:
Code:
ngrep -e host xx.xx.xxx.170 not port 1057
ngrep -e port 1057 -x host xx.xx.xxx.170
ngrep -e not port 1057 -x host xx.xx.xxx.170
etc.
Im running a web server on port80, but i want traffic coming from ip 212.333.111.222 on port 80 to be fowarded to port 9020 on the same server that my web server is rinning at that is my sshd port
View 1 Replies View RelatedI 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..
I want to do a simple port redirect, i.e. whatever comes trough whatever interface on port AAAA will get redirected to port BBBBI thought that iptables -t nat -I PREROUTING --source 0/0 --destination 0/0 -p tcp --dport AAAA -j REDIRECT --to-ports BBBBhowever it doesn't work, e.g. nc -v -w2 -z localhost AAAA gives:
nc: connect to localhost port AAAA (tcp) failed: Connection refused
while
nc -v -w2 -z localhost BBBB
[code]....
I'm running ASSP on Ubuntu 10.04.1 it's mostly working fine. I have one problem which has been bugging me for some time. I don't want to filter outbound mail, but if I can relay (proxy) my outbound mail through ASSP, then it can automatically add to the whitelist.
As ASSP is a proxy, I need a server to send it to once ASSP receives it. I've tried my ISP, but this failed and they weren't willing to confirm if a connection attempt was received at their end.
Current setup
Inbound
mx -> router -> ASSP -> Exchange 2003
Outbound
Exchange 2003 -> mx
I'd like to setup outbound as either
Exchange 2003 -> ASSP -> <ISP> SMTP relay
Exchange 2003 -> ASSP -> <relay running on Ubuntu eg postfix>
Can anyone help me with troubleshooting steps or a better suggestion for how I can set this up. I'd love to know why my ISP setup didn't work, but I don't know a tool for monitoring IP traffic in Ubuntu SE, in windows I use Wireshark is there any equivalent I can setup for Ubuntu or a tool I can use in windows which will show all traffic, Ubuntu and windows server are on the same netgear switch, not sure it's smart enough to copy all traffic to another port for monitoring.
I have a question, on my firewall at work I am seeing a constant flow of denies from many different source IP addresses, of tcp/udp destination port 53372 & 53375.What in the world is that, and why these two ports over and over
View 1 Replies View RelatedI'm simply trying to make a little restriction on www packets under two rules:
1. Allow inbound/outbound www packets (works!)
2. DROP inbound traffic to port 80 from source ports less than 1024. (DOES NOT WORK!)
Now, technically, when i use hping to test my rules, hping3 192.168.100.100 -S -p80 -s 1023 I should NOT receive any packets. However, i still receive packets, which means my rule that says less than 1024 does not work. (see below)
And this is my iptables rules in shell-script so far:
#!/bin/sh
DEFAULT_NIC=eth0
SERVER_IP="192.168.100.100"
ALLOWED_WWW_PORT=80
IPT="/sbin/iptables"
[Code].....
When I use the following command:
ssh user@ssh_server -L 5500:localhost:5500 -p 22
everything works fine. I can log in, and local port forwarding is done. Otherwise when I use the command:
ssh user@ssh_server -R 5500:localhost:5500 -p 22
I get an error "remote port forwarding failed for listen port 5500". However when I try remote port forwarding in WinXP by use of putty there is no problem...
I'm trying to use iptables in order to forward all the incoming packets for port 5555 to port 5556 on the same server (192.168.2.101).
I wrote the following commands:
iptables -A PREROUTING -t nat -i any -p tcp --dport 5555 -j DNAT --to 192.168.2.101:5556
iptables -A FORWARD -p tcp -m state --state NEW -d 192.168.2.101 --dport 5556 -j ACCEPT
I'm using a Debian servers, as router/firwall.. I've two ethernet interfaces into the server, one for wan and one for lan. The i use SNAT so my LAN clients can access the internet throgh the debian router. That is working... Now i want to be able to access servers on the LAN site from the WAN site, and i wanna use port address translation (PAT). I have a FTP server running on a lan server, so i'm trying to portward port 21.
iptables -t nat -A PREROUTING -p tcp -i eth1 -d (WANIP) --dport 21 -j DNAT --to 192.168.1.2:21
When people try to access my FTP from the WAN site, they are redirected to the local FTP server, and they are promted for crendentials, but when the credentials are typed, and the local ftp server should answer the wan request, the connections dies.
The wan clients are being promted for credentials, so they are redirected to the local lan server, but after that the connections dies, so i think there is some kind of nat problem, when the local lan server is trying to respond to the wan request..
Here i my iptables script:
#flush table
iptables -F
#input regler
[code]....
I make an application on GNU/Linux which listening on a MULTICAST stream, so I open my unconnected socket, bind it on a MULTICAST address and a port, join the multicast group with the "setsockopt (IP_ADD_MEMBERSHIP)", then I receive datagram on my socket.
Now I've two different instances of the same application that run with their own MULTICAST address and port. And what I found strange is that, after a misconfiguration, I switch the ports, for example:
Emitting on 225.0.0.1/23451 and 225.0.0.2/23452
Receiving on 225.0.0.1/23452 and 225.0.0.2/23451
And my receiving part doesn't care about the MULTICAST address, it looks like the socket is listening on the port number only! I mean that the receiver [225.0.0.1/23452] take its datagrams from emitter [225.0.0.2/23452] and vice-versa!
I am realtively new to BGP. I use BGP in my network to advertise my /20 subnet. What i would like to know is what is the point of accepting routes from your neighbouring AS(ISP)?My ISP has given me a default gateway, and no matter what I want to reach on the internet I have to go through that default gateway, so why populate the routing table with soo many routes?also, as i understand it, there are 3 kinds of routes that you can accept, those are full routes, directly connected routes and default routes. What is the diffrence between them and again how do they affect routing since my network only has the one default gateway?
View 2 Replies View RelatedWe 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 want to set my ip as static and port forward it through a specific port can anyone help me with this im using ubuntu 10 with 64 bit OS
View 1 Replies View RelatedHow can i redirect data received on a port to another port located in a different machine? Can i do this using IPTABLES ?
View 4 Replies View RelatedI have a mail server on which I would like to block port 25 on my eth0 for everyone except our external spam filter. the problem is that I want our users to be able to connect via port 10025 which is forwarded to port 25, which then is blocked...
View 2 Replies View RelatedI had to add them to my firewall script when I installed openvpn on my dd-wrt router:
iptables -I FORWARD -i br0 -o tun0 -j ACCEPT
iptables -I FORWARD -i tun0 -o br0 -j ACCEPT
iptables -I INPUT -i tun0 -j REJECT
iptables -t nat -A POSTROUTING -o tun0 -j MASQUERADE
what should I add/change to set up port forwarding of port 1000 to ip 192.168.1.200. also how to get the answer sent by 192.168.1.200 follow the same route used by the data received through port forwarding.
