Dell PowerConnect 7048P User Manual - Page 143

Table 8-1. Applications that Checkpoint Data Application IGMP/MLD Snooping IPv6 NDP iSCSI LLDP OSPFv2 OSPFv3 Route Table Manager SIM Voice VLAN Checkpointed Data Multicast groups, list of router ports, last query data for each VLAN Neighbor cache entries Connections List of interfaces with MED devices attached Neighbors and designated routers Neighbors and designated routers IPv4 and IPv6 dynamic routes The system's MAC addresses. System up time. IP address, network mask, default gateway on each management interface, DHCPv6 acquired IPv6 address. VoIP phones identified by CDP or DHCP (not LLDP) Switch Stack MAC Addressing and Stack Design Considerations The switch stack uses the MAC addresses assigned to the master unit. NOTE: Each switch is assigned three consecutive MAC addresses. The switch uses the MAC addresses for the service port, network port, and routing interfaces. A stack of switches uses the MAC addresses assigned to the master unit. If the backup unit assumes control due to a master unit failure or warm restart, the backup unit continues to use the original master unit's MAC addresses. This reduces the amount of disruption to the network because ARP and other L2 entries in neighbor tables remain valid after the failover to the backup unit. Stack units should always be connected with a ring topology (or other biconnected topology), so that the loss of a single stack link does not divide the stack into multiple stacks. If a stack is partitioned such that some units lose all connectivity to other units, then both parts of the stack start using the same MAC addresses. This can cause severe problems in the network. Managing a Switch Stack 143