KB.15.15

Figure 65 Distributed trunking switch-to-switch square topology

Distributed trunking interconnect protocol

Distributed trunking uses the distributed trunking interconnect protocol (DTIP) to transfer DT-specific

configuration information for the comparison process and to synchronize MAC and DHCP snooping

binding data between the two DT peer switches.

NOTE: For DHCP snooping to function correctly in a DT topology, the system time must be the

same on both switches, and the ISC must be trusted for DHCP snooping.

Configuring distributed trunking

The following parameters must be configured identically on the peer devices or undesirable behavior

in traffic flow may occur:

• The ISC link must have a VLAN interface configured for the same VLAN on both DT switches.

• VLAN membership for all DT trunk ports should be the same on both DT switches in a DT pair.

• IGMP-snooping or DHCP-snooping configuration on a DT VLAN should be the same on both

DT switches. For example, for a DT, if IGMP-snooping or DHCP-snooping is enabled on a

VLAN that has a DT port as a member port of the VLAN, the same must be configured on the

peer DT on the same VLAN.

• Loop-protection configuration on a DT VLAN should be the same for both DT switches.

Distributed trunking overview 161