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Questions tagged [tcp-ip]

63 questions
12
votes
2 answers

Redirect an external IP to localhost?

Is it possible to redirect all calls to an external IP on internet, to localhost (without use of hosts)? I have an old application and I don't have the source code and this application try to connect to a postgres server using an IP Can I instruct…
danilo
  • 1,865
9
votes
1 answer

How to check if ICMP blocking is enabled in a system..?

A VLAN pool enabled newly is not pinging the device. Connectivity issues are not there. Can this be because if ICMP Blocking is enabled? How to check the status of the same?
kiran bbnl
  • 829
6
votes
1 answer

How to configure iptables to work with tcpcrypt?

Background OS: Ubuntu 16.04 x64 running on VirtualBox I am a developer with minimal Ubuntu/Linux knowledge and have been assigned to a project where the goal is to utilize tcpcrypt when communicating with certain endpoints. tcpcrypt comes with a…
raidensan
  • 111
6
votes
1 answer

TCP send performance issue on 18.04

I am playing around with Ubuntu 18.04 and I'm noticing TCP performance regression that prevents me from upgrading my current running servers since they are very latency-sensitive. For my particular use-case, I implemented a simple TCP test program…
octal
  • 111
4
votes
1 answer

How to use wireless(wlan0) and wired (eth0) at the same time?

I am working with an embedded system in my lab and to remotely access the board, I have given a static IP to the board on Ethernet connection. The problem is - due to security reasons Ethernet connection cannot access general internet. The only way…
kshitij srivastava
  • 41
4
votes
1 answer

Server stops accepting connections after ~120,000 active on 18.04.3

I'm running a type of perf test where I have a simple TCP server with 4 IP addresses that is listening on a port and getting connections from several other computers on the local network. Everything works fine up to just under 120,000 active…
Denis
  • 61
3
votes
1 answer

sysctl: cannot stat /proc.sys/net/ipv4/tcp_frto_response

I'm trying to tune some tcp parameters to enhance the performance of the wireless network I have. One of those system parameters are tcp_frto and tcp_frto_response. The first value I was able to read and change but when I try to read the second one,…
los
  • 31
3
votes
0 answers

How to enlarge network buffer size in Ubuntu?

How to enlarge network buffer size in Ubuntu? I want to make some file transfers with low latency and I want to try it increasing the network buffer size. How could I do it?
eightShirt
  • 131
3
votes
0 answers

What do I need to tweak to avoid TCP duplicate/out of order ACKs during file upload from some computers?

I'm seeing an issue with a specific combination of circumstances that causes TCP duplicate ACKs to be sent. This happens with a service hosted on Ubuntu Server 20.04. I have a web service that, among many things, accepts uploads with…
ACKIsAFittingName
  • 31
3
votes
0 answers

Changing TCP ACK delay

TCP ACK is described here: https://en.wikipedia.org/wiki/TCP_delayed_acknowledgment I know very little about this - I just learned about it via this ticket that I filed with Node.js: https://github.com/nodejs/node/issues/21091 Basically I am using…
Alexander Mills
  • 706
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2
votes
2 answers

Ubuntu 17.10 VPN

Enabling VPN connection from the Network manager automatically add's IPv6 address to DHCP Wired connection even if it's disabled on the settings. This causes the VPN to leak on all DNS address queries that are for IPv6 addresses. How can I prevent…
SamTzu
  • 91
2
votes
1 answer

How to Reduce Buffer Bloat on an Ubuntu Based Router

I had an old Dell Optiplex 790 (added dual Intel PCI-E gigabit NIC) sitting around that I decided to make into a router using Ubuntu 16.04 and the guide found here…
jcoop7777
  • 23
  • 5
2
votes
1 answer

What user permission is required to listen to port 8080

I'm trying to run Cuberite under its own username, cuberite. However, when I sudo -u cuberite ./Cuberite I'm unable to connect to it with my web browser: $ sudo lsof -i :8080 COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME Cuberite 1091…
Josh
  • 183
2
votes
0 answers

Rsyslog losing message when sending via TCP

I was trying to build a custom Syslog server on the Windows platform, which I, for a start, am implementing a basic TCP listener (server). I encountered problem and I have asked this on StackOverflow: Question. Later on, I realized the problem…
Jai
  • 121
2
votes
1 answer

I need a simple TCP load balancer in Ubuntu

I would like to create a load balancer for RDP connections only, that’s one TCP port only and would like to avoid anything more complex like Nginx. I don’t need cache, or anything else, just take an incoming tcp connection and establish an internal…
Chema
  • 21
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