Reference Guide

482 | Layer 2
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Figure 22-5. Server Clustering: Failover and Balancing Not Preserved
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
vlan-flooding on the Dell Force10
switch at the time that the Microsoft cluster is configured (Figure 22-6).
As shown in Figure 22-6, the server MAC address is given in the Ethernet frame header of the ARP reply,
while the virtual MAC address representing the cluster is given in the payload. The
vlan-flooding command
directs the system to discover that there are different MAC addresses in an ARP reply and associate the
virtual MAC address with the VLAN connected to the cluster. Then, all traffic destined for the cluster is
flooded out of all member ports. Since all of the servers in the cluster receive traffic, failover and balancing
are preserved.
Figure 22-6. Server Cluster: Failover and Balancing Preserved with the vlan-flooding Command
VLAN 1
Client
Data
fnC0028mp
MAC
S1
Server1:
IP
S1
MAC
S2
IP
S2
Server2:
M
icrosoft Server Cluster:
IP
Cluster
MAC
Cluster
MAC
S3
IP
S3
Server3:
MAC
S4
IP
S4
Server4:
Client
Data
vlan-flooding configured
fnC0029mp
Source MAC: MAC
Cluster
Destination MAC: MAC
Client
Source IP: IP
S1
Source MAC: MAC
S1
Type: 0x0806
Pad
CRC
Ethernet Frame Header
ARP Reply
MAC
S1
Server1:
IP
S1
MAC
S2
IP
S2
Server2:
M
icrosoft Server Cluster:
IP
Cluster
MAC
Cluster
MAC
S3
IP
S3
Server3:
MAC
S4
IP
S4
Server4:
VLAN 1