All Questions
45
questions
0
votes
1
answer
379
views
Ubuntu server does not accept any request from outside
I have a database in ubuntu server, and it works on server, the port is 5436.However, I can not connect it from outside.
I use ufw order
it lists as below
[17] 5436 (v6) ALLOW IN ...
- 180
0
votes
1
answer
605
views
Fail2ban doesn't persist manual banned IPs after service restart
Just upgraded from f2b v0.9.6 to v0.10.5 on Ubuntu 14.04 using this thread, and it is banning normally according to my old jails that i copied from my previous version.
But when i restart the service,...
- 848
0
votes
0
answers
201
views
Udp Routing with 2 ports
I'm trying to pull udp stream to my ubuntu 14.04 and can't handle routing.
I'm having 2 ports
1. is port with internet connection(local adress)
2. is port with udp multicast streams with dynamic ...
- 193
0
votes
0
answers
3k
views
How to open port 22 with iptables
I am not able to ssh into an ec2-instance. when I run nmap -Pn 10.xxx.xxx.xx I see that instance doesn't have port 22 open
I have a security group added to this instance that has a ssh rule added. I ...
- 101
0
votes
1
answer
555
views
How to detect https traffic with iptables u32 module? [closed]
How would I detect http traffic through u32 module of iptables?
2
votes
0
answers
760
views
BUG: unable to handle kernel NULL pointer dereference at 0000000000000030 (Ubuntu 14.04, kernel: 4.4.0-31) [closed]
I get the following "log" output using "crash"
[558679.340881] ip_tables: error: `ERROR'
[558679.344717] BUG: unable to handle kernel NULL pointer dereference at 0000000000000030
[558679.344779] IP: ...
- 51
0
votes
0
answers
49
views
Ubuntu 14.04 UFW issues / Syslog
I have a strange behavior with UFW...
I added rules for a specific port (12666 TCP and UPD v4/v6) and in the syslog file I can see that UFW blocks many or all connections to this port...
How could it ...
- 35
0
votes
1
answer
145
views
boot 14.04 iptables fails intermittently [duplicate]
I have a kvm VM with Ubuntu 14.04 set as a firewall in a virtual network
(with eth0 and eth1)
This is not a course but at work. I have to learn this.
Intermittently eth1 will fail to come up.
In /...
- 1
2
votes
1
answer
38k
views
How to open a closed port in Ubuntu?
I was trying to kill a process which was running on the port 8080 and utilize it for remote debugging purpose.
Where my source code is on my host machine, and the compiled jar is in another Ubuntu ...
- 203
5
votes
2
answers
20k
views
NAT using iptables on Ubuntu 16.04 doesn't work
I used to use Ubuntu 14.04 trusty for our NAT server (build on Google Cloud Platform), but recently I tried to use the Ubuntu 16.04 xenial.
I configured perfectly same as I've done in 14.04, but it ...
0
votes
1
answer
2k
views
connection refused on port 4000 in ubuntu14.04? [closed]
I tried to telnet (telnet 10.12.1.14 4000 or nc -zv 10.12.1.14 4000 )on port 4000 and giving the result as follows.
root@cwl2:~# nc -zv 10.12.1.14 4000
nc: connect to 10.12.1.14 port 4000 (tcp) ...
0
votes
0
answers
108
views
Making own iptables rules in ubuntu 14.04
I am using ubuntu 14.04, and I want to build my own firewall.
How can I make an iptables rule for a specific user - to not allow him to make something... ?
- 71
0
votes
0
answers
5k
views
Connecting to postgreSQL port on Ubuntu 14.04
For a project I am working on we are using an Ubuntu 14.04 server and just to be clear, I am a Linux noob who is just starting out using Linux. This project requires the use of PostgreSQL 9.3, which I ...
- 101
0
votes
0
answers
376
views
Can't enable TARPIT in iptables
I have an Ubuntu 14.04 box and I'm trying to get the tarpit feature to work in iptables. I have added the the xtables-addons-common and xtables-addons-dkms packages but I still get the following ...
- 1
1
vote
1
answer
1k
views
PuTTy connection time-out? (Ubuntu Server 14.04)
I am trying to use PuTTy to manage my Ubuntu 14.04 Server. I am clearly doing something wrong with my SSH setup. Perhaps it has to do with my firewall rules?
Here are my rules in iptables:
What do I ...
- 19
1
vote
2
answers
11k
views
Can't connect to smtp.gmail.com on port 465 or 587
I have an Ubuntu 14.04 (Trusty Tahr) is mounted on AWS and i cannot connect to the SMTP GMail service vía:
SSL(465):
## $ telnet smtp.gmail.com 465 ##
Trying 74.125.28.109...
Trying 74.125.28.108...
...
- 119
2
votes
2
answers
10k
views
UFW BLOCK syslog - tcp/ip is blocked and this is allowed in UFW - GPS TRACKING/TCP/UDP report server
Well I'm new in this things, I have been searching a solution for my problem, reset, and do it again, specify port and protocol, port in and out with a protocol, but i can't.
Information
problem: ...
- 475
0
votes
1
answer
682
views
Create a permanent rule for iptables in Ubuntu
In order to establish connection with my Ubuntu server I have to add the following rule to iptables:
sudo iptables -A INPUT -p tcp --dport 80 -j ACCEPT
Everything is working until I reboot the ...
- 327
3
votes
1
answer
15k
views
What is the UH flag in routing table
I'm using an Ubuntu machine as a server and it has two network interfaces. One is the 10.10.10.0/ 24 range and the other is 192.168.0.0 /24 range. I was trying to bridge these network interfaces as ...
- 143
1
vote
0
answers
5k
views
Setting up NAT forwarding using iptables on ubuntu server 14.04
I have a server with 2 ethernet interfaces(em1 and em2). em1 is the internet facing interface(192.168.16.113) and em2 has a static address(10.1.1.100) connected to a switch. I have configured the ...
- 41
0
votes
2
answers
887
views
fail2ban won't work
A few days ago I setup a new whole Server (Mailserver with Zarafa / Postfix, Apache, MySQL, and so on). Everything works fine.. except fail2ban. Fail2ban do nothing. He don't even act if something is ...
- 1
1
vote
1
answer
10k
views
Unable to connect to mongo on remote server
I have installed mongo on machine1(Ubuntu 14.04.3 LTS server) in my local network. I have also opened the port 27017 as mentioned in this guide using following commands:
sudo iptables -A INPUT -p tcp ...
- 131
0
votes
1
answer
157
views
Iptables and Deny issue
I've configured iptables with FWBuilder, and for some reason there is a rule that is constantly dropped, and I don't know why, because all the address IP from and to 10.208.x.x (first server) and 10....
- 1
2
votes
2
answers
3k
views
Forward port from 80 to 9000 not working
I'm trying to host an app on Ubuntu 14.04 and want to redirect traffic from 80 to 9000.
sudo iptables -A INPUT -p tcp --dport 80 -j ACCEPT
sudo iptables -A INPUT -p tcp --dport 9000 -j ACCEPT
sudo ...
- 131
2
votes
1
answer
1k
views
configure iptables to redirect traffic to a specific IP address
I have just began using iptables. I have a server with a public ip address
(A.A.A.A) wich is hosting a Virtual Machine (B.B.B.B) on
local network.
I want to redirect all inbound traffic on the port ...
- 63
1
vote
1
answer
5k
views
Log of refused connections by iptables [duplicate]
I suspect iptables to refuse some connection attempts I do on some ports. How to view the log of connections refused by iptables?
I use iptables on Kubuntu 14.04 LTS x64.
sudo iptables -v -x -n -L ...
- 3,472
0
votes
1
answer
1k
views
How to drop packets to closed ports instead of reject?
When i connecting to closed port i'm getting 'Connection refused'. I wan't to disable sending of this response in Ubuntu 14.04.
Can I do it?
- 111
13
votes
5
answers
2k
views
Type of code conversion used in Linux executable files
I want to ask that what type of encoding is used to make linux executable files e.g. hexadecemal, binary or anything else.
how is it converted ?
Is there any way to get back the original code from ...
- 589
1
vote
1
answer
2k
views
how to block ip address with IPTABLES on ubuntu 14.04 desktop?
First, I've been setting up local IP Public IP add.
in directory /etc/network/ interfaces file
# This file describes the network interfaces available on your system
# and how to activate them. ...
- 353
0
votes
1
answer
5k
views
Too many connections and iptables is not working to limit connections per ip
I have a dedicated server with 32GB RAM. It works all fine till some punters came to ddos my server. I had really high uplink bandwidth usage (over 150Mbps). I looked at netstat with the following ...
- 81
3
votes
2
answers
68k
views
Open a port on Ubuntu 14.04
I have seen similar threads, but they didn't help me.
I am using Ubuntu 14.04.2 LTS (GNU/Linux 2.6.32-042stab108.5 x86_64) on my VPS.
I ran a node.js application on port 9000, but this port is ...
- 133
3
votes
2
answers
3k
views
How to find out where iptables rules come from?
I used to have my own set of iptables rules on my Ubuntu 14.04 LTS installation. This was residing in /etc/network/if-pre-up.d/iptables.
Now, apparently after another apt-get dist-upgrade it looks ...
- 151
0
votes
1
answer
3k
views
Ip forwarding to another subnet
Right now i am working on testing a MAAS setup (physical hardware). I have deployed juju and can access it within the network (10.0.3.0).
I have two interfaces eth0, internet facing, eth1 where 10.0....
1
vote
0
answers
353
views
regenerate iptables from "iptables -L"after disk failure
My system disk failed catastrophically. I've replaced and mostly restored the OS on a new disk but all I have for my iptables is the output from iptables -L. Is there a way to automatically recreate ...
- 1,181
2
votes
3
answers
7k
views
opening port 80 on AWS
I created a AWS EC2 VPS(ubuntu v14) on which I want to open port 80 so that my website can run.
But unfortunately, I am not able to open port 80.
For this, I first ran the command:
$ sudo iptables -...
- 21
0
votes
1
answer
190
views
How to use my ubuntu server as router?
+---+
eth1- *.1.6| S |
=========| |
|PC1|private net --------------------
| |=============...
- 155
1
vote
0
answers
7k
views
how to open a port under Ipv4 instead of Ipv6
How I can open a port under Ipv4 instead of Ipv6 on ubuntu
tcp 0 0 127.0.0.1:3306 0.0.0.0:* LISTEN -
tcp 0 0 127.0.1.1:53 0.0....
- 141
1
vote
0
answers
275
views
Redirect connections from VPS to IP
I'm trying to develop my own "DNS" server using subdomains. Let' say I have this struture:
VPS server with Ubuntu
VPS server IP: 1.1.1.1
External computers on: 2.2.2.2 and 3.3.3.3
Subdomain '...
- 707
1
vote
1
answer
198
views
Adding firewall rule makes multiple entries
I am trying to add a rule to my Ubuntu 14 iptables to allow NTP (123) though using the command for allowing Incoming Traffic on Specific Ports Basic iptables How to?
Here is my command:
sudo ...
- 23
3
votes
1
answer
4k
views
Why does my firewall reset upon reboot?
I host gameservers on my dedicated server and was setting up the firewall a few days ago (had to set everything up again, hard drive failed and I forgot to back-up).
Everything ran fine, firewall ...
- 135
9
votes
1
answer
56k
views
ERROR: problem running ufw-init
I tried setting up ufw on my remote Ubuntu 14.04 server so i installed it and allowed ssh with the command
sudo ufw allow ssh
after that I tried to enable ufw but I get the following error:
ERROR: ...
- 191
1
vote
1
answer
4k
views
iptables - unable to initialize table filter
I have a firewall file saved in /etc/firewall.conf. Everything is ok, I can use it for "iptables-restore /etc/firewall.conf" with success.
So, starting from this file, I created a php script(that ...
0
votes
1
answer
446
views
Iptables troubles
I used webwin for iptables management and reset the firewall over webmin (to clear out all the old stuff). I also disabled the feature Activate at book.
After that I installed iptables-persistent for ...
- 273
0
votes
1
answer
1k
views
Setup NAT on Ubuntu 14.04
I'm trying to insert my desktop between an appliance and the rest of the network to monitor the traffic coming off of it due to some security concerns. I'd like to setup NAT so that the devices behind ...
- 7,309
0
votes
3
answers
994
views
keep iptables up to date
I've installed iptables-persistent (Ubuntu 14.04) with the impression that it automatically saves iptables on shutdown but that appears not to be the case? It seem to load saved rules at startup but ...
- 2,542