All Questions
29
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
0
answers
160
views
Can't block specific IP address with iptables, Ubuntu 16.04
I'm trying to troubleshoot Fail2ban recognizing our http-get-dos trigger, but not actually banning the offending host. I can see it adding entries to iptables rules, but they don't have any affect.
So ...
0
votes
1
answer
66
views
Why this script blocking browsing of any website after running it?
i found this script here
How to stop the synattack?
#!/bin/sh
FWVER=0.05
echo "Loading Protect rule set version $FWVER..\n"
# The location of the iptables program
#
IPTABLES=/sbin/iptables
#...
- 35
0
votes
1
answer
332
views
What does this `iptables -t filter -X` command mean
What does this command mean:
iptables -t filter -X
What is the purpose of -X?
And what's the difference between -X and -F?
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
5
votes
1
answer
4k
views
UFW occasionally blocking HTTPS (443/TCP) although configured to allow that port on Ubuntu 16.04
On my Ubuntu 16.04 machine, I have configured UFW like this:
$ sudo apt-get install ufw
$ sudo ufw limit 22/tcp
$ sudo ufw allow 80/tcp
$ sudo ufw allow 443/tcp
$ sudo ufw enable
Now if I run sudo ...
- 416
0
votes
0
answers
118
views
Getent Hosts For Port 1519/tcp -iptables 16.04
I have a scenario:
i will have to protect my network from unsolicited access from my DMZ machine, configure node-A to allow new connections on port 1915/tcp from hosts (obtained by 'getent hosts node-...
- 51
0
votes
1
answer
2k
views
Problem opening ports on Ubuntu 16.04
I am trying to open several ports on my computer running Ubuntu 16.04, which would allow me to run drone simulation software on it and connect to it a companion computer (Odroid).
I have tried ...
- 103
0
votes
1
answer
70
views
Ubuntu 16.04 - Wi-fi , IP is on a network different than my gateway
I have a partitioned Lenovo pc. One partition with Ubuntu desktop 16.04, one with Windows 10.
Windows has internet connection, Ubuntu does not. It is on a different network.
I tried gathering some ...
- 11
1
vote
2
answers
938
views
Setting and configuring a firewall
Newbie here.
I've found the following rules to set a firewall, (from the book how Linux works)
iptables -P INPUT DROP # the default policy
iptables -A INPUT -s 127.0.0.1 -j ACCEPT
iptables -A ...
- 149
1
vote
1
answer
540
views
Asking help with iptables
Firstly I want to ask why my rules.v4 looks so complicated after using: iptables -F. I thought it will be empty after flushing:
# Generated by iptables-save v1.6.0 on Tue Jan 9 21:25:13 2018
*filter
...
- 21
0
votes
0
answers
74
views
Ubuntu VM keeps rejecting incoming connections
Brand new Ubuntu 16.04 Server installed with just Postgres and OpenSSH servers in addition to the standard packages. After machine boots up, I can ssh and DB connect to the box. A few minutes later, I ...
- 1
0
votes
0
answers
436
views
lxd container with openvpn server does not apply iptables nat rule
I'm trying to setup openvpn on one of my lxd containers to allow access to the container network. The server seem to work and I can access (ping) containers which have a static route pointing to the ...
- 866
0
votes
2
answers
1k
views
What is the correct way to do port redirect on same host?
I have installed jenkins on amazon ec2, ubuntu 16.04 machine. jenkins up on port 9090. I wanted to redirect port 80(http) to port 9090 and access jenkins with http://ci.mymachine.com/. I have followed ...
- 101
1
vote
3
answers
14k
views
Why don't my iptables log?
I have a linux server running on Ubuntu 16.04. Today I installed PSAD, a Intrusion Detection System.
PSAD works by analyzing the logfiles of iptables. So, first thing to do before using PSAD is ...
- 113
1
vote
1
answer
12k
views
Opening port with IP tables and UFW doesn't appear to open port
I have attempted to open port 443 on a server I'm working on (Ubuntu 16.04):
/sbin/iptables -I INPUT -p tcp --dport 433 -m state --state NEW,ESTABLISHED -j ACCEPT
The port doesn't appear to be open:
...
3
votes
0
answers
924
views
Iptables Rules for Ubuntu 16.04 based Firewall
I am trying to set iptables rules in my server to use it as Ubuntu 16.04 based Firewall. I have fair knowledge in Ubuntu. I did some search in Ubuntu help site and in Askubuntu. I came up with the ...
- 31
0
votes
0
answers
1k
views
PSAD Status Firewall Setup Warning
Every time I restart my Ubuntu 16.04 Server I receive the following in an email.
[-] You may just need to add a default logging rule to the
'filter' 'INPUT' chain on HomeOne. For more ...
- 890
1
vote
0
answers
60
views
Second Network Interface in Subnet of default route
I've got a 16.04 server with interface em1 in my companys a.b.0.0/16 subnet AB. For reasons reasons I can't change, there is a protected subsubnet ABC within this range called a.b.c.0/24 which I only ...
- 111
1
vote
0
answers
2k
views
Network manager is adding unwanted rules to iptables
I am trying to create a wifi router using ubuntu 16 and network manager. I can create the wifi hotspot and an ethernet connection but no device that sits downstream over ethernet can ping a device ...
- 145
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 ...
4
votes
1
answer
2k
views
Access internet over Wifi instead of ethernet
I am setting up networking on my ODROID C1 running Ubuntu 16.04.1 LTS (GNU/Linux 3.10.104-181 armv7l)
. Internet access over WiFi works fine but when I plug-in the ethernet cable (which has no ...
- 49
15
votes
1
answer
15k
views
How can we replace iptables with firewalld in ubuntu 16.04?
In Ubuntu 16.04, can we install firewalld services?
- 428
9
votes
3
answers
51k
views
Where is iptables in Ubuntu 16.04?
I'm reading through the source code that writes directly to system iptables in /system/xbin/iptables in Android. I would like to do the same in Ubuntu without using the iptables command.
Where is ...
- 203
0
votes
1
answer
3k
views
Unable to block port 25
I have a dedicated server with an LXC container on it. The container has IP: 11.22.33.44.
I want to block outgoing port 25 of this container, so that the container cannot send out email.
From the ...
- 231
1
vote
1
answer
3k
views
Accidently flushed iptables - restore
Im running ubuntu 16.04 and i have accidently flushed my iptables while trying to troubleshoot a slow internet issue. I used following command
iptables -F
Now i cannot open any website, log into ...
- 185
1
vote
1
answer
3k
views
Revert iptables
I created the following temporary rule that I enable occasionally but I would like to remove it without the need of restarting the machine.
Can someone provide me the command?
sudo iptables -t nat -...
- 568
0
votes
1
answer
2k
views
IPtables Config to Passthrough Internet 16.04
I am struggling to finish the config on my Ubuntu 16.04 fileserver to pass on the internet connection to my HTPC. See the network layout below:
[Internet] <--> [DHCP Router] <--> (eno1).[...
- 103
1
vote
1
answer
2k
views
UFW not working in 16.04 server. Refers to earlier kernel module?
I am trying to move our mail server based on 12.04 to a brand new installation of 16.04 server.
When I run sudo ufw status, I get:
ERROR: problem running iptables: modprobe: ERROR: ../libkmod/...
- 41