ip igmp snooping last-member-query-intervalFast Convergence after MSTP Topology ChangesThe following describes the fast convergence feature.When a port transitions to the Forwarding state as a result of an STP or MSTP topology change, DellNetworking OS sends a general query out of all ports except the multicast router ports. The host sends aresponse to the general query and the forwarding database is updated without having to wait for thequery interval to expire.When an IGMP snooping switch is not acting as a querier, it sends out the general query in response tothe MSTP triggered link-layer topology change, with the source IP address of 0.0.0.0 to avoid triggeringquerier election.Egress Interface Selection (EIS) for HTTP and IGMPApplicationsThe functionality to configure the egress interface selection (EIS) mechanism is supported on the Z9000platform.You can now use EIS to isolate the management and front-end port domains for HTTP and IGMP traffic.Also, EIS enables you to configure the responses to switch-destined traffic by using the management portIP address as the source IP address. This information is sent out of the switch through the managementport instead of the front-end port.Management Egress Interface Selection (EIS) feature is applicable only for the out-of-band (OOB)management port. The references to management default route or static route in this chapter denote theroutes configured using the management route command. The management default route can beeither configured statically or returned dynamically by the DHCP client. A static route points to themanagement interface or a forwarding router.Transit traffic (destination IP not configured in the switch) that is received on the front-end port withdestination on the management port is dropped and received in the management port with destinationon the front-end port is dropped.Switch-destined traffic (destination IP configured in the switch)• Received in the front-end port with destination IP equal to management port IP address ormanagement port subnet broadcast address is dropped.• Received in the management port with destination IP not equal to management IP address ormanagement subnet broadcast address is dropped.Traffic (switch initiated management traffic or responses to switch-destined traffic with management portIP address as the source IP address) for user-specified management protocols must exit out of themanagement port. In this chapter, all the references to traffic indicate switch-initiated traffic andresponses to switch-destined traffic with management port IP address as the source IP address.In customer deployment topologies, it might be required that the traffic for certain managementapplications needs to exit out of the management port only. You can use EIS to control and the trafficcan exit out of any port based on the route lookup in the IP stack.Internet Group Management Protocol (IGMP) 311
