Server Fault Stack Exchange
Server Fault Stack Exchange

Questions tagged [tcpip]

TCP and IP are two important protocols used in networking today. Due to their importance, the Internet Protocol Suite is also commonly known as "TCP/IP"

464 questions
6
votes
3 answers

Problems with MDNS flooding on port 5353 UDP

I am running into a big issue at a small network i manage. This network is an Apple network, with airport extremes, expresses, mac book pro's, imac's, ipads, iphones etc... I went to add something to this network today and noticed lights flashing…
Dani Cela
  • 123
  • 1
  • 2
  • 10
6
votes
1 answer

What does a magic packet look like?

What does a magic packet contain and what options does the protocol provide?
Sander Versluys
  • 911
  • 1
  • 10
  • 12
6
votes
1 answer

Docker container unable to connect to one specific external IP, yet host can

This is a puzzler, and I'm hoping that by writing a StackOverflow question, I gain some fresh insights. In a nutshell, I'm trying to figure out why I can access https://sts.nih.gov from a host machine, but not from a docker container on the same…
Paul Dixon
  • 1,516
  • 3
  • 23
  • 37
6
votes
1 answer

What are some TCP tuning tips for a service hit by iPhone clients on mobile networks like 3G?

I am a developer that has the good+bad situation of designing a network service that will be hit very hard by iPhone clients. The iPhone app has over 10MM downloads in the past year and now I'm bringing the users online to interact with each…
z8000
  • 792
  • 1
  • 7
  • 15
5
votes
0 answers

What is the difference between net.core.netdev_max_backlog and net.ipv4.tcp_max_syn_backlog

Several docs on the net describe these options as following: net.core.netdev_max_backlog: Maximum number of packets, queued on the INPUT side, when the interface receives packets faster than kernel can process…
madhead
  • 151
  • 6
5
votes
5 answers

How to extend IP Range from 192.168.1.1 to 192.168.2.254

Here's my question. I currently have a network setup to have Static IP manually assigned between 192.168.1.1 and 192.168.1.99 and the rest (192.168.1.100 through 192.168.1.254) assigned automatically by DHCP server hosted on a IPCop server. Now, I'd…
Marc-Andre R.
  • 2,477
  • 3
  • 23
  • 21
5
votes
1 answer

How does stunnel redirect traffic?

I am familiar with the stunnel.conf and I know how to specify which unencrypted ports it listens to and to which encrypted ports it redirects, but I would like to understand how it gets the power to "snatch" the packets from a server listening on…
Bill The Ape
  • 165
  • 6
5
votes
6 answers

TCP Sessions and IP Changes

What happens to a TCP session when the IP of a client changes? I did a simple test of having netcat listen on a port, and connecting to that port from a client machine. I then changed the IP of the client while that nc session was open and sent…
Kyle Brandt
  • 83,619
  • 74
  • 305
  • 448
5
votes
1 answer

ping -a sometimes returns host name and sometimes returns FQDN. Why? Does this mean DNS is corrupt somehow?

I have a Windows machine called abcd for example and it uses DHCP to receive an IP address (172.28.45.5 for example) When I perform ping -a 172.28.45.5 sometimes I receive abcd as the hostname. Sometimes I receive the FQDN, for example…
Blue Tongue
  • 107
  • 2
  • 3
  • 8
5
votes
3 answers

Practical Anycast

I've read How can I send visitors to the closest server using DNS? post, but there's still some thing, on a practical level that I don't understand. Say I have two servers. One in NY another in Paris. Both of them have different IP adresses 1.1.1.1,…
Daniel
  • 157
  • 1
  • 6
5
votes
1 answer

Sender Information Not Cached on the Receiver During an ARP Request

I'm currently trying to get my head around more advanced networking concepts. The way I am doing this is by going on one of the servers I look after as a sysadmin and running network captures to see and make sense of the data. (The machine I am…
Trinitrotoluene
  • 370
  • 2
  • 6
5
votes
2 answers

custom route not working on windows

My windows laptop is directly connected to 192.168.1.0/24 (wireless lan). I access 10.21.0.0/16 though a router that is connected to both networks. The routing works fine with this configuration. I have a VPN, that connects to 10.0.0.0/8. The VPN…
Michael Closson
  • 221
  • 1
  • 4
  • 10
5
votes
2 answers

IP address used by nslookup and ping is different

I have a web server hosted in the network. It has a domain name registered. However, I also host a DNS server for the LAN. So, when someone wants to access the web server, it would check the DNS server and use the internal address 192.168.x.x. The…
ht2
  • 61
  • 1
  • 1
  • 4
5
votes
1 answer

TCP Windows Size vs Socket Buffer Size on Windows

I am new to Windows networking. When people talk about TCP tuning on Windows platform, they always mention about TCP Window Size. I am wondering whether Windows uses the concept of "Socket Buffer Size"? On Windows XP, the TCP window size is fixed.…
userpal
  • 613
  • 4
  • 10
  • 17
5
votes
2 answers

How do I fake dropped packets (or actually make them fail)?

Background One of our clients suffers from an intermittant problem with their internet where it will drop packets when a user downloads a large file (their IT is looking into the problem). I have an application consisting of a Web Server running…
Daniel James Bryars
  • 279
  • 3
  • 11
1 2 3
…
30 31