atti amaxi

slow

This bash script offers quick shortcuts to simulate slower network connections. It is useful when you need to simulate a wireless network on a Linux network server, especially when you are using a virtual machine guest on your local machine or in the cloud.

slow 3G                   # Slow network on default eth0 down to 3G wireless speeds
slow reset                # Reset connection for default eth0 to normal
slow vsat --latency=500ms # Simulate satellite internet  with a high latency
slow dsl -b 1mbps         # Simulate DSL with a slower speed than the default

slow modem-56k -d eth0 # Simulate a 56k modem on the eth1 device. eth0 is unchanged.

	### 1: Drop invalid packets ###
	/sbin/iptables -t mangle -A PREROUTING -m conntrack --ctstate INVALID -j DROP

	### 2: Drop TCP packets that are new and are not SYN ###
	/sbin/iptables -t mangle -A PREROUTING -p tcp ! --syn -m conntrack --ctstate NEW -j DROP

	### 3: Drop SYN packets with suspicious MSS value ###
	/sbin/iptables -t mangle -A PREROUTING -p tcp -m conntrack --ctstate NEW -m tcpmss ! --mss 536:65535 -j DROP

	### 4: Block packets with bogus TCP flags ###

	#!/bin/sh
	## backup each mysql db into a different file, rather than one big file
	## as with --all-databases. This will make restores easier.
	## To backup a single database simply add the db name as a parameter (or multiple dbs)

	## Putting the script in /var/backups/mysql seems sensible... on a debian machine that is
	## Create the user and directories
	# mkdir -p /var/backups/mysql/databases
	# useradd --home-dir /var/backups/mysql --gid backup --no-create-home mysql-backup
	## Remember to make the script executable, and unreadable by others