Default Behavior; Configuring The Switch For Microsoft Server Clustering - Dell Force10 S4810P Configuration Manual

Default Behavior

When an ARP request is sent to a server cluster, either the active server or all of the servers send a reply,
depending on the cluster configuration. If the active server sends a reply , the Dell Force10 switch learns the
active server's MAC address. If all servers reply, the switch registers only the last received ARP reply, and
the switch learns one server's actual MAC address
learned.
Since the virtual MAC address is never learned, traffic is forwarded to only one server rather than the
entire cluster, and failover and balancing are not preserved
Figure 29-3. Server Clustering: Multiple ARP Replies
Microsoft Server Cluster: IP Cluster
Figure 29-4. Server Clustering: Failover and Balancing Not Preserved
Microsoft Server Cluster: IP Cluster

Configuring the Switch for Microsoft Server Clustering

To preserve failover and balancing, the Dell Force10 switch must learn the cluster's virtual MAC address,
and it must forward traffic destined for the server cluster out all member ports in the VLAN connected to
the cluster. To ensure that this happens, you must configure the command
Force10 switch at the time that the Microsoft cluster is configured
630
| Layer 2
IP S1
Server1:
MAC S1
IP S2
Server2:
MAC S2
MAC Cluster
IP S3
Server3:
MAC S3
IP S4
Server4:
MAC S4
Server1:
IP S2
Server2:
MAC Cluster
IP S3
Server3:
Server4:
(Figure 29-3); the virtual MAC address is never
(Figure
Source MAC: MAC S1
Destination MAC: MAC Client
Type: 0x0806
Ethernet Frame Header
VLAN 1
IP S1
MAC S1
VLAN 1
MAC S2
MAC S3
IP S4
MAC S4
29-4).
Source IP: IP S1
Pad
Source MAC: MAC Cluster
ARP Reply
Data
on the Dell
vlan-flooding
(Figure 29-5).
CRC
Client
fnC0027mp
Client
fnC0028mp