Server-To-Client Data Forwarding - Cisco WS-X6066-SLB-APC - Content Switching Module Software Manual

Understanding How ASLB Works

Server-to-Client Data Forwarding

Figure 42-3
of events, and
The traffic from the servers to the router or client devices works in the same manner, but in the reverse
direction, as the data forwarding described in the
page 42-4
for all packets going to the router. For the traffic in the client-to-server direction, the source MAC
address of the packet was unmodified.
Figure 42-3 Server to Client ASLB Packet Flow
Clients
Table 42-4 Server to Client ASLB Packet Flow
Path
Number VLAN
1 20
2 10
3—N 20
N + 1 20
N +2... 10
1. This MAC address has an Xtag value of 14 in the Layer 2 table for this packet's VLAN.
2. MAC address of the server that the LocalDirector selected.
3. CIP = client's IP address.
4. VIP = virtual-IP address.
Catalyst 6000 Family Software Configuration Guide—Releases 6.3 and 6.4
42-6
shows how data is forwarded from the servers to the clients.
Table 42-5 lists the Layer 3 table entries.
with the exception that the LocalDirector put its own MAC address as the source of the packet
VLAN 10
VLAN 20
MAC
Destination MAC Source
Address Address
1
Router MAC Server MAC
Router MAC LocalDirector
1
MAC
1
Router MAC Server MAC
1
Router MAC Server MAC
Router MAC LocalDirector
1
MAC
"Client-to-Server Data Forwarding" section on
Catalyst 6500
series switches
P
K
Path 3
P
P
R
L
P
P
P
M
A
B
Path 2
LocalDirector
IP Destination IP Source
Address Address
2 3 4
CIP VIP
CIP VIP
CIP VIP
CIP VIP
CIP VIP
Chapter 42
Table 42-4 lists the sequence
Server pool
S1
S2
S3
Path 1
Flags Action
SYN Candidate entry in
Layer 3 table
- Enabler packet
- Full ASLB MLS
entry created
FIN/RST Path 1 redirect
FIN/RST Path 2
Configuring ASLB
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