Server-To-Client Data Forwarding - Cisco WS-C6506 Software Manual

Understanding How ASLB Works

Server-to-Client Data Forwarding

Figure 54-3
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 described in the
is that the LocalDirector put its own MAC address as the source of the packet for all the packets that are
going to the router. For the traffic in the client-to-server direction, the source MAC address of the packet
was unmodified.
Figure 54-3
Clients
Table 54-4 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. The MAC address of the server that the LocalDirector selected.
3. CIP = client's IP address.
4. VIP = virtual-IP address.
Catalyst 6500 Series Switch Software Configuration Guide—Release 8.7
54-6
shows how data is forwarded from the servers to the clients.
Table 54-5 lists the Layer 3 table entries.
"Client-to-Server Data Forwarding" section on page
Server-to-Client ASLB Packet Flow
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
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 54
Table 54-4
54-4. The exception
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
lists the sequence
OL-8978-04