Configuration Guide User guide
830 FastIron Configuration Guide
53-1002494-02
Multi-Chassis Trunking Overview
22
MCT data flow
MCT can be deployed in a single-level configuration involving two MCT cluster devices or in a
cascading configuration with a pair of MCT cluster devices operating as switches and another pair
operating as routers. Refer to “Single-level MCT example” on page 867 for a single-level illustration
and configuration example, and “Two-level MCT example” on page 871 for a two-level or cascading
configuration example.
Basic MCT data flow works as follows.
Broadcast, unknown unicast, and multicast (BUM) traffic from a client through a CCEP
1. Traffic originates at the client.
2. Because the link between the client switch and the MCT cluster is a trunk, the traffic travels
over one physical link. In the example in Figure 96, the traffic travels over the link towards
cluster device 2. The traffic enters the MCT cluster through the CCEP of cluster device 2.
3. The traffic is sent to any local CEPs and CCEPs. It passes to the peer cluster device over the
ICL link, where it is sent to the peer device’s local CEPs.
4. Traffic does not pass back down to the client through the CCEP.
Refer to Figure 96.
FIGURE 96 MCT data flow - BUM traffic from CCEP
OR
OR
CEP
CCEP
Client A
Cluster
Device 1
Cluster
Device 2
X
3
3
3
3
2
2
4
1