1. http://blog.xuite.net/ganpin917/home/51499181-Cisco+Switch+log+%E5%AF%AB%E5%85%A5%E9%81%A0%E7%AB%AFLinux+Log+Server
2. https://supportforums.cisco.com/document/24661/how-configure-logging-cisco-ios
3. http://www.cisco.com/c/en/us/td/docs/switches/datacenter/sw/5_x/nx-os/system_management/configuration/guide/sm_nx_os_cg/sm_5syslog.html
4. http://www.cisco.com/c/en/us/td/docs/ios/fundamentals/configuration/guide/15_1s/cf_15_1s_book/cf_config-logger.html
5. http://www.cisco.com/c/en/us/td/docs/ios/fundamentals/command/reference/cf_book/cf_l1.html
