1Fenner W. RFC 2236-Internet group management protocol, Version 2 [DB/OL]. http://www. ietf. org/rfc/rfc2236. txt, 1997-11.
2Christensen M, Kimball K, Solensky F. Considerations for IGMP and MLD snooping switches [DB/OL].http://www. ietf. org/internet-drafts/draft-ietf-magmasnoop-10. txt,2003-10.