All Questions
18
questions with no upvoted or accepted answers
2
votes
1
answer
671
views
Why does my virtual machine (Debian on Proxmox) not respond to a TCP SYN of another VM even though it arrives?
I got a very strange problem and I am out of ideas to solve it. I hope anyone over here has a helpful idea.
Some info about the virtual machines:
VM0: Debian 10 - 192.168.10.102 [+ 2 more interfaces]
...
- 41
1
vote
0
answers
2k
views
SSH fails to connect from one computer but works from other computers
Problem
I have an external VPS server running Ubuntu 18.04 with openssh-server 7.6p1. I can connect via ssh to this server from many different networks except from one particular client. This ...
- 111
1
vote
0
answers
212
views
Firewall : Is inbound required for getting response while Outbound rule already there?
I developed one MVC web application which have Web APIs and hosted in Amazon Instance and one windows application for calling those APIs for getting response from that server.
Both Web and Windows ...
1
vote
2
answers
757
views
iptables SNAT target and TCP ACK packets
I need to establish a TCP connection where the client is spoofing its IP for all outgoing traffic. My first attempt was to add a rule to the POSTROUTING chain like so:
iptables -t nat -A POSTROUTING -...
- 11
0
votes
0
answers
43
views
Teardrop detected from TCP ACK from myself
I'm experimenting with linux (Debian 5.10) networking to allow me to connect two networks (eg. 192.168.0.0/24 with 172.17.0.0/16) together.
Setup
In my case it is a small server with one NIC, hosting ...
- 126
0
votes
1
answer
337
views
How to send back TCP packets using iptables
I am trying to demonstrate TCP communication with a Ubuntu 18.04 box (which mocks a QNX setup) that does not have a listener installed. Consider that due to some license issues it might not be ...
0
votes
1
answer
2k
views
Block outgoing connection from server to Internet, but enable specific TCP port access from outside
I am using Mikrotik RouterOS on a Mikrotik router.
There is a server in my network from which every outgoing connection using every protocol should be disabled. I achieved this with a following rule:
/...
- 944
0
votes
1
answer
2k
views
TCP communcation - HyperV virtual machine opening port on host
Here's the summary of my fight to connect to a port on the hypervisor host from a VM hosted on the same machine:
Set up in the Hyper-V Manager:
Virtual Switch Settings
Internal
'Enable virtual LAN ...
- 11
0
votes
1
answer
467
views
Samsung Smart TV UA43N5300ARLXL/UA43N5300ARXXL unable to connect to internet over UFW firewall
I have a home network with a Raspberry Pi at the center running Pihole and UFW. The Pihole is both the DHCP as well as DNS server.
Ever since I started using Pi Hole I've not had any issues until ...
- 21
0
votes
2
answers
280
views
If I disable iptables its working. Which rule is making my websites a timeout?
I have a VPS with nginx but no website is working and timeout is sent. When I disable iptables everything is fine. But no idea which rule/s is taking the problem. Any help?
$sudo iptables -S
-P INPUT ...
- 1
0
votes
0
answers
216
views
Iptables configuration
Here is my iptables script. Can it be better ?
Thanks in advance !
#!/bin/bash
#iptables-restore < /etc/iptables.test.rules
iptables -F
iptables -X
iptables -t nat -F
iptables -t nat -X
iptables ...
- 1
0
votes
0
answers
82
views
in Debian server, IPTABLES PREROUTING behave differenty for different ports
I have following three rules in my iptables firewall
-A PREROUTING -i eth0 -p tcp -m tcp --dport 12346 -j DNAT --to-destination 11.207.2.4:12350
-A PREROUTING -i eth0 -p tcp -m tcp --dport 12348 -j ...
0
votes
0
answers
343
views
Block TCP connection to certain domain
Using ProcMon.exe, I see that I got an outgoing TCP request to
MyUser-PC.home:54988 -> ec1-51-49-47-232.eu-west-1.compute.amazonaws.com:https
And then an incoming TCP request:
MyUser-PC.home:...
- 157
0
votes
0
answers
29
views
How to know that I passed the firewall from the TCP connections?
In my company, in order to access some intranet-sites, I have first to login to webpage (which I suppose is a firewall or something) with my account. If I login from FF for example, I can access the ...
- 196
0
votes
0
answers
981
views
How to block HTTP 302 redirection package by matching a specific string on Location?
The HTTP response I want to block has:
Header
HTTP/1.1 302 Found
Location: http://www.yxjiaodai.com/ad/?id=1023&url=http%3A//a1819.oadz.com/link/C/1819/3081547/dtMdon4l79FwsIo2JXEHqtdp5eQ_/p007/...
- 193