Configuring Tcp Parameters - Cisco catalyst 6500 series Configuration Note

Configuring Virtual Servers
Router(config-slb-policy)# url-map map4
Router(config-slb-policy)# exit
Router(config-module-csm)#
Router(config-module-csm)# vserver bar1
Router(config-slb-vserver)# virtual 10.1.0.86 tcp 80
Router(config-slb-vserver)# slb-policy pc1
Router(config-slb-vserver)# slb-policy pc2
Router(config-slb-vserver)# serverfarm bosco
Router(config-slb-vserver)# inservice
Router(config-slb-vserver)#

Configuring TCP Parameters

Transmission Control Protocol (TCP) is a connection-oriented protocol that uses known protocol
messages for activating and deactivating TCP sessions. In server load balancing, when adding or
removing a connection from the connection database, the Finite State Machine correlates TCP signals
such as SYN, SYN/ACK, FIN, and RST. When adding connections, these signals are used for detecting
server failure and recovery and for determining the number of connections per server.
The CSM also supports User Datagram Protocol (UDP). Because UDP is not connection-oriented,
protocol messages cannot be generically sniffed (without knowing details of the upper-layer protocol)
to detect the beginning or end of a UDP message exchange. Detection of UDP connection termination
is based on a configurable idle timer. Protocols requiring multiple simultaneous connections to the same
real server are supported (such as FTP). Internet Control Management Protocol (ICMP) messages
destined for the virtual IP address are also handled (such as ping).
To configure TCP parameters, perform this task:
Command
Step 1
Router(config-module-csm)# vserver
virtserver-name
Step 2
Router(config-slb-vserver)# idle duration
1.
2.
This example shows how to configure TCP parameters for virtual servers:
Router(config-module-csm)# vserver barnett
Router(config-slb-vserver)# idle 10
The CSM provides support for fragmented TCP packets. The TCP fragment feature only works with
VIPs that have Level 4 policies defined and will not work for SYN packets or for Layer 7 policies. To
support fragmented TCP packets, the CSM matches the TCP fragments to existing data flows or by
matching the bridging VLAN ID. The CSM will not reassemble fragments for Layer 7 parsing. Because
the CSM has a finite number of buffers and fragment ID buckets, packet resending is required when there
are hash collisions.
When enabling TCP splicing, you must designate a virtual server as a Layer 7 device even when it does
not have a Layer 7 policy. This option is only valid for the TCP protocol.
Catalyst 6500 Series Content Switching Module Configuration Note
6-4
Enter the exit command to leave a mode or submode. To return to the Router (config)> top level of the menu, enter the end
command.
The no form of this command restores the defaults.
Chapter 6 Configuring Virtual Servers, Maps, and Policies
Purpose
Identifies the virtual server and enters the virtual
server configuration mode
Configures the amount of time (in seconds) that
connection information is maintained in the absence
of packet activity for a connection
1,2
.
2
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