From: Doyal Alexander (imitguru@yahoo.com)
Date: Fri Mar 12 2004 - 15:03:02 GMT-3
OIL => outgoing interface list...Joining a Multicast Group
When a host wants to join an IP multicast group, it sends an IGMP join (also known as a join message) specifying the IP multicast group it wants to join (for example, group 224.1.2.3). The switch hardware recognizes that the packet is an IGMP report and redirects it to the switch CPU. The switch installs a new group entry for 01-00-5e-01-02-03 and adds the host port and the router port to that entry. The switch then relays the join from the host to all multicast router ports. The designated multicast router for the segment adds the outgoing interface (OIF) to the outgoing interface list (OIL) for the group and begins forwarding multicast traffic for 224.1.2.3 to this segment.
When a second host in this VLAN wants to join group 244.1.2.3, it sends out an IGMP join for this group. The switch hardware recognizes that this is an IGMP control packet and redirects it to the switch CPU. Since the switch already has a group entry for 01-00-5e-01-02-03 in this VLAN, it just adds the second host port to the entry. Because this is not the first host joining the group, the switch suppresses the report (does not send it to the router).
"Joseph D. Phillips" <jphillips@ufcwdrugtrust.org> wrote:What is OIL?
This archive was generated by hypermail 2.1.4 : Thu Apr 01 2004 - 08:15:17 GMT-3