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@bradoaks
bradoaks / hfsc-shape.sh
Created April 25, 2011 14:51 — forked from eqhmcow/hfsc-shape.sh
HFSC - linux traffic shaping's best kept secret
#!/bin/bash
# As the "bufferbloat" folks have recently re-discovered and/or more widely
# publicized, congestion avoidance algorithms (such as those found in TCP) do
# a great job of allowing network endpoints to negotiate transfer rates that
# maximize a link's bandwidth usage without unduly penalizing any particular
# stream. This allows bulk transfer streams to use the maximum available
# bandwidth without affecting the latency of non-bulk (e.g. interactive)
# streams.
@jboner
jboner / latency.txt
Last active December 1, 2025 11:35
Latency Numbers Every Programmer Should Know
Latency Comparison Numbers (~2012)
----------------------------------
L1 cache reference 0.5 ns
Branch mispredict 5 ns
L2 cache reference 7 ns 14x L1 cache
Mutex lock/unlock 25 ns
Main memory reference 100 ns 20x L2 cache, 200x L1 cache
Compress 1K bytes with Zippy 3,000 ns 3 us
Send 1K bytes over 1 Gbps network 10,000 ns 10 us
Read 4K randomly from SSD* 150,000 ns 150 us ~1GB/sec SSD
@klange
klange / _.md
Last active December 23, 2024 14:40
It's a résumé, as a readable and compilable C source file. Since Hacker News got here, this has been updated to be most of my actual résumé. This isn't a serious document, just a concept to annoy people who talk about recruiting and the formats they accept résumés in. It's also relatively representative of my coding style.

Since this is on Hacker News and reddit...

  • No, I don't distribute my résumé like this. A friend of mine made a joke about me being the kind of person who would do this, so I did (the link on that page was added later). My actual résumé is a good bit crazier.
  • I apologize for the use of _t in my types. I spend a lot of time at a level where I can do that; "reserved for system libraries? I am the system libraries".
  • Since people kept complaining, I've fixed the assignments of string literals to non-const char *s.
  • My use of type * name, however, is entirely intentional.
  • If you're using an older compiler, you might have trouble with the anonymous unions and the designated initializers - I think gcc 4.4 requires some extra braces to get them working together. Anything reasonably recent should work fine. Clang and gcc (newer than 4.4, at le
@cloudnull
cloudnull / neutron-vpnaas-fwaas-lbaas-configSetup.rst
Last active September 4, 2019 08:53
Setup Openstack Havana with Neutron using VPNaaS (VPN as a Service), FWaaS (Firewall as a Service), LBaaS (Load Balancer as a Service).

Installing Openstack VPNaaS, LBaaS, and FWaaS

This brief overview assumes that Openstack Havana has been installed and setup with Neutron Networking. If you have not already done this, you could use "https://github.com/cloudnull/rcbops_allinone_inone" or devstack to setup a dev box and then perform the following actions.


  • install "openswan":

    # (apt-get install openswan neutron-plugin-vpn-agent) || (yum install openswan openstack-neutron-vpn-agent && chkconfig neutron-vpn-agent on)
    
#!/bin/bash
#
# Copyright (c) 2015, Intel Corporation
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#
# * Redistributions of source code must retain the above copyright notice,
# this list of conditions and the following disclaimer.
# * Redistributions in binary form must reproduce the above copyright
@nerdalert
nerdalert / Netfilter-IPTables-Diagrams.md
Last active November 28, 2025 07:06
Linux NetFilter, IP Tables and Conntrack Diagrams

Linux NetFilter, IP Tables and Conntrack Diagrams

IPTABLES TABLES and CHAINS

IPTables has the following 4 built-in tables.

1) Filter Table

Filter is default table for iptables. So, if you don’t define you own table, you’ll be using filter table. Iptables’s filter table has the following built-in chains.

@xjdrew
xjdrew / client.go
Last active June 20, 2025 01:31
golang tls client and server, require and verify certificate in double direction
package main
import (
"crypto/tls"
"crypto/x509"
"flag"
"io"
"io/ioutil"
"log"
"os"
@Hakky54
Hakky54 / openssl_commands.md
Last active November 13, 2025 12:38 — forked from p3t3r67x0/openssl_commands.md
OpenSSL Cheat Sheet

OpenSSL Cheat Sheet 🔐

Install

Install the OpenSSL on Debian based systems

sudo apt-get install openssl