Systems Administration Problem Solvers

Month: October 2009

  • Arizona “Action to Foreclose”

    Arizona Tax Lien “Action to Foreclose” notification process: 42-18202. Notice A. At least thirty days before filing an action to foreclose the right to redeem under this article, but not more than one hundred eighty days before such an action is commenced or may be commenced under section 42-18101 the purchaser shall send notice of […]

  • Routing Hackers To /dev/null (Blackhole)

    Add: route add -host attacker_ip 127.0.0.1 -blackhole Remove: route delete -host attacker_ip 127.0.0.1 -blackhole The above will route all traffic from the “attacker_ip” to a blackhole. This is useful when you see someone relentlessly attacking any daemon on your server (ssh, http, ftp, etc). [ad#Google Adsense]

  • Decrypt SMIME E-Mails – BlackBerry/iPhone

    I, and most everyone I deal with, use SMIME e-mail certificates from Verisign/Thawte/Home Brew. Unfortunately, these e-mails can not be viewed on an BlackBerry (without BES) or iPhone. I overcame this by creating an alias on my server that would receive e-mails, decrypt them, and send them back to me -> UNENCRYPTED. [NOTE: If you […]

  • FreeBSD: Aliasing IPs

    [ad#Google Adsense] Edit /etc/rc.conf The primary IP of the machine will be defined by a line that looks similar to this: ifconfig_rl0=”inet 192.168.1.2 netmask 255.255.255.0″ To add additional IPs you simply: ifconfig_rl0_alias0=”inet 192.168.1.3 netmask 255.255.255.255″ ifconfig_rl0_alias1=”inet 192.168.1.4 netmask 255.255.255.255″ [ad#Google Adsense]

  • FreeBSD: Moving To A Larger Harddrive

    [ad#Google Adsense] Moving to a Larger Hard Drive Applicable to: FreeBSD 4.3 and Higher This Sheet describes the procedure I used to move my company’s FreeBSD system to a larger hard drive. 1. Verify that the system supports two hard drives. If not, rebuild the kernel with support for two hard drives: # ATA and […]

  • Resume SCP / SSH Downloads

    Works most of the time: rsync –archive -partial -progress –rsh=ssh

  • Networking Subnets – Quick Reference

    [ad#Google Adsense] notation resulting subnet netmask shorthand number of addresses 255.255.255.0 /24 [8-bit] 28 = 256 = 254 hosts + 1 bcast + 1 net base 255.255.255.128 /25 [7-bit] 27 = 128 = 126 hosts + 1 bcast + 1 net base 255.255.255.192 /26 [6-bit] 26 = 64 = 62 hosts + 1 bcast + […]