All Questions
20
questions
0
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74
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Linux 6.5 netfilter NAT reuses TCP ports in TIME_WAIT status?
In my understanding, Linux (netfilter)'s NAT doesn't reuse TCP ports in TIME_WAIT status, but seemingly Linux >= 6.5 reuses TCP ports in TIME_WAIT, even if the destination is the same.
For example, ...
- 41
1
vote
3
answers
4k
views
Understanding port forwarding and NAT
I've got some confusion about port forwarding vs NAT. I know the problems NAT causes for P2P, and that there exist some solutions to it (STUN,TURN,etc) which require a relay server to setup direct ...
CommunityBot
- 1
1
vote
1
answer
172
views
How can I get connection attempts behind a NAT router?
I've been playing with nftables recently and set up logging every incoming TCP SYN packet to my local machine. I noticed every minute I get a couple of random connection attempts on various ports (...
- 465k
0
votes
1
answer
84
views
What is the correct way of shorten this nat based multiple ports?
Can these rules shorten to single line:
post-up iptables -t nat -A PREROUTING -i vmbr0 -p tcp --dport 3050 -j DNAT --to-destination 192.168.1.3:3050
post-up iptables -t nat -A PREROUTING -i vmbr0 -p ...
- 400
0
votes
1
answer
413
views
Relay TCP upload traffic and make download traffic go directly to the client
This is a supplement for iptables SNAT for UDP rule is only applied to some traffic
In fact, I have three machines:
the client
the target server
the relay server
What's my motivation for doing this?
...
- 13
0
votes
0
answers
130
views
Returning tcp/udp packets to sender
I'm using a Linux machine with WiFi hotspot to test the WiFi stack of an embedded device. For context, the embedded device is designed to send and receive encrypted packets to/from a remote server.
To ...
- 1
0
votes
3
answers
587
views
Connect a socket to another PC in same NAT
Hey I've got two machines on the same network. They get their IP info back from an external webserver. Same IP due to NAT but different ports locally. Hmm that's weird.. they can't socket up or even ...
- 2,886
0
votes
1
answer
2k
views
SSH file transfers slow with lots of TCP retransmissions
Good evening,
I use SFTP (File Transfer over SSH) from a computer (Windows 10) to a Synology NAS. Both devices are behind NAT on different locations. Around 3 weeks ago, whenever I initiated a ...
- 17k
2
votes
2
answers
4k
views
TCP/UDP hole punching from and to the same NAT network
I was wondering if tcp/udp hole punching would still work when you are in the same network (behind a NAT), and what the packet's path would be.
What happens when using hole punching on the same ...
CommunityBot
- 1
4
votes
1
answer
2k
views
how do the world's peer to peer networks handle UDP hole punching?
With Bitcoin and Ethereum in the news so much I started to look into peer to peer networks more. My question is, do most of the people running full Bitcoin or Ether nodes have to open port 8333 to the ...
- 1
0
votes
1
answer
890
views
NAT setup – unable to ping mapped host
I am setting up NAT on a Linksys WRT54GL for the first time. I'm trying to map a statically-assigned laptop address of 192.168.1.109 to port 40000, and ping it. My end goal is to enable TCP and UDP ...
- 239
2
votes
0
answers
1k
views
netflix stall via linux iptables nat, tcp checksum errors (with workaround)
I've been trying to track down this problem for several days. I still haven't worked out what is going on, or how to fix it properly, but I do have a workaround.
Problem summary
Netflix stalls when ...
- 21
0
votes
1
answer
665
views
Windows TCP redirection
On my Windows PC (192.168.1.123) , I have an application that connects to 1.2.3.4 on port 3333 by default, I would like to redirect the traffic to 127.0.0.1 port 2222.
Under Linux, this can be ...
CommunityBot
- 1
0
votes
2
answers
1k
views
Webserver behind NAT router not reachable
I have a mysterious problem with a little server that I'm running at home, behind a NAT router. I'm running several web and other services there, which I can also access from outside my LAN through ...
- 742
2
votes
0
answers
983
views
Tunnelling TCP connection through NAT
My server is in my school's NAT and my desktop computer is in my home NAT. I want to SSH to my server from home. I normally used school's VPN, but recently for some reason I can't. So I'm looking for ...
- 11