Cisco Catalyst 3750-E - Page 970

38-24
Catalyst 3750-E and 3560-E Switch Software Configuration Guide
OL-9775-08
Chapter 38 Configuring EtherChannels and Link-State Tracking
Understanding Link-State Tracking
Figure 38-6 Typical Link-State Tracking Configuration
The configuration in Figure 38-6 ensures that the network traffic flow is balanced as follows:
• For links to switches and other network devices
– Server 1 and server 2 use switch A for primary links and switch B for secondary links.
– Server 3 and server 4 use switch B for primary links and switch A for secondary links.
• Link-state group 1 on switch A
– Switch A provides primary links to server 1 and server 2 through link-state group 1. Port 1 is
connected to server 1, and port 2 is connected to server 2. Port 1 and port 2 are the downstream
in
terfaces in link-state group 1.
– Port 5 and port 6 are connected to distribution switch 1 through link-state group 1. Port 5 and
port 6 are the upstream interfaces in link-state group 1.
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Network
Layer 3 link
Server 1 Server 2 Server 3 Server 4
Distribution
switch 1
Distribution
switch 2
Switch A Switch B
Port
1
Port
5
Port
4
Port
3
Port
2
Port
2
Port
3
Port
4
Port
8
Port
7
Port
6
Port
5
Port
1
Port
6
Port
7
Port
8
Link-
state
group 2
Link-state
group 1
Link-state
group 1
Link-state
group 2
Link-state
group 2
Link-
state
group 1
Link-
state
group 1
Primary link
Secondary link
Link-
state
group 2