Advanced Configuration

This chapter describes how to configure advanced server load balancing (SLB) on the CSM and contains these sections:

Configuring URL Hashing

When you choose a server farm for a connection, you can select a specific real server in that server farm. You can choose least connections, round robin, or URL hashing to select a real server.

URL hashing is a load-balancing predictor for Layer 7 connections. You can configure URL hashing on the CSM on a server farm-by-server farm basis. The CSM chooses the real server by using a hash value based on a URL. This hash value may be computed on the entire URL or on a portion of it. To select only a portion of the URL for hashing, you can specify the beginning and ending patterns in the URL so that only the portion of the URL from the specified beginning pattern through the specified ending pattern is hashed.

Configuring a URL Hashing Predictor

You configure the URL hashing predictor on a server farm-by-server farm basis. Unless you specify a beginning and an ending pattern (see the "Configuring Beginning and Ending Patterns" section), the entire URL is hashed and used to select a real server.

You must configure URL hashing for all server farms that will be using the URL hashing predictor, regardless of whether they are using the entire URL or a beginning and ending pattern.

To configure URL hashing as a load-balancing predictor for a server farm, perform this task:

This example shows how to configure URL hashing and load-balancing predictor for a server farm:

Configuring Beginning and Ending Patterns

When you configure a beginning and ending pattern, you do so at the virtual server level. The pattern you define will apply to all the server farms assigned to all of the policies in that virtual server that have URL hashing enabled.

The beginning and ending pattern delimits the portion of the URL that will be hashed and used as a predictor to select a real server from a server farm that belongs to any policy assigned to that virtual server.

	Command	Purpose
	`Router(config-slb-sfarm)# predictor hash url`	Configures the URL hashing and load-balancing predictor for a server farm.

To hash a substring of the URL instead of the entire URL, specify the beginning and ending patterns in vserver vserver-name submode with the url-hash begin-pattern pattern-a command and url-hash end-pattern pattern-b command. Hashing occurs at the start of the beginning pattern and goes to the ending pattern.

For example, in the following URL, if the beginning pattern is c&k=, and the ending pattern is &, only the substring c&k=c is hashed:

Note Beginning and ending patterns are restricted to fixed constant strings. General regular expressions cannot be specified as patterns. If no beginning pattern is specified, hashing begins at the beginning of the URL. If no ending pattern is specified, hashing ends at the end of the URL.

This example shows how to configure beginning and ending patterns for URL hashing:

Configuring Firewall Load Balancing

Firewall load balancing allows you to scale firewall protection by distributing traffic across multiple firewalls on a per-connection basis. All packets belonging to a particular connection must go through the same firewall. The firewall then allows or denies transmission of individual packets across its interfaces.

This section describes how to configure firewall load balancing for regular and stealth firewalls. It covers the following topics:

Understanding How Firewalls Work

A firewall forms a physical barrier between two parts of a network, the Internet and an intranet, for example. When a firewall accepts a packet from one side (the Internet), it sends the packet through to the other side (the intranet). A firewall can modify a packet before passing it through or send it through unaltered. When a firewall rejects a packet, it usually drops the packet and logs the dropped packet as an event.

After a session is established and a flow of packets begins, a firewall can monitor each packet in the flow or allow the flow to continue, unmonitored, depending on the policies that are configured on that firewall.

Firewalls Types

Regular firewalls have a presence on the network; they are assigned an IP address that allows them to be addressed as a device and seen by other devices on the network.

Stealth firewalls have no presence on the network; they are not assigned an IP address and cannot be addressed or seen by other devices on the network. To the network, a stealth firewall is part of the wire.

Both firewall types examine traffic moving in both directions (between the protected and the unprotected side of the network) and accept or reject packets based on user-defined sets of policies.

How the CSM Distributes Traffic to Firewalls

The CSM load-balances traffic to devices configured in server farms. These devices can be servers, firewalls, or any IP-addressable object including an alias IP address. The CSM uses load-balancing algorithms to determine how the traffic is balanced among the devices configured in server farms, independent of device type.

Note We recommend that you configure Layer 3 load balancing on server farms that contain firewalls, because of the interactions between higher-layer load-balancing algorithms and server applications.

Supported Firewalls

For regular firewalls, a single CSM or a pair of CSMs balances traffic among firewalls that contain unique IP addresses, similar to how it balances traffic to servers.

For stealth firewalls, a CSM balances traffic among unique VLAN alias IP address interfaces on another CSM that provide paths through stealth firewalls. A stealth firewall is configured so that all traffic moving in both directions across that VLAN moves through the firewall.

Layer 3 Load Balancing to Firewalls

When the CSM load-balances traffic to firewalls, the CSM performs the same function that it performs when it load-balances to servers. To configure Layer 3 load balancing to firewalls, follow these steps:

Step 2

In serverfarm submode, enter the predictor hash address command.

Step 3

Assign that server farm to the virtual server that accepts traffic destined for the firewalls.

Note When you configure Layer 3 load balancing to firewalls, use source NAT in the forward direction and destination NAT in the reverse direction.

Types of Firewall Configurations

•

Dual-CSM configuration—Firewalls are located between two CSMs. The firewalls accept traffic from one CSM and send it to a second CSM for load balancing to servers or return to the requesting device.

•

Single-CSM configuration—Firewalls accept traffic from a CSM and send it back to the same CSM for load balancing to servers or return to the requesting device.

CSM Firewall Configurations

•

Mixed firewalls (stealth and regular) for dual CSM configurations ( Figure 5-4)

In Figure 5-1, traffic moves through the firewalls and is filtered in both directions. The figure shows the flow from the Internet to the intranet. On the path to the intranet, CSM A balances traffic across VLANs 5, 6, and 7 through firewalls to CSM B. On the path to the Internet, CSM B balances traffic across VLANs 15, 16, and 17 through firewalls to CSM A. CSM A uses the VLAN aliases of CSM B in its server farm, and CSM B uses the VLAN aliases of CSM A in its server farm.

In Figure 5-2, traffic moves through the firewalls and is filtered in both directions. The figure shows the flow from the Internet to the intranet. VLANs 11 and 111 are on the same subnet, and VLANs 12 and 112 are on the same subnet.

In Figure 5-3, traffic moves through the firewalls and is filtered in both directions. The figure only shows the flow from the Internet to the intranet, and VLANs 11 and 111 are on the same subnet.
VLANs 12 and 112 are on the same subnet.

In Figure 5-4, traffic moves through both the regular and stealth firewalls and is filtered in both directions. The figure shows the flow from the Internet to the intranet. VLANs 5, 6, and 7 are shared between CSM A and CSM B. On the path to the intranet, CSM A balances traffic across VLANs 5, 6, and 7 through firewalls to CSM B. On the path to the intranet, CSM B balances traffic across VLANs 5, 6, and 7 through firewalls to CSM A.

Figure 5-4 Mixed Firewall Configuration for Stealth and Regular Firewalls (Dual CSMs Only)

Fault-Tolerant CSM Firewall Configurations

•

Mixed firewalls (stealth and regular) in a fault-tolerant dual CSM configuration

In Figure 5-5, the traffic moves through the firewalls and is filtered in both directions. The figure only shows the flow from the Internet to the intranet through the primary CSMs, and VLANs 11 and 111 are on the same subnet. VLANs 12 and 112 are on the same subnet.

Configuring Stealth Firewall Load Balancing

This section describes how to configure firewall load balancing for stealth firewalls and covers the following information:

Stealth Firewall Configuration

In a stealth firewall configuration, firewalls connect to two different VLANs and are configured with IP addresses on the VLANs to which they connect. (See Figure 5-6.)

Location	Traffic Direction	Arrives On	Exits On
1	To intranet	VLAN 10	VLANs 101 and 103
2	To intranet	VLANs 101 and 103	VLAN 20
3	To Internet	VLAN 20	VLANs 102 and 104
4	To Internet	VLANs 101 and 103	VLAN 10

Figure 5-6 shows two regular firewalls (Firewall 1 and Firewall 2) sandwiched between two CSMs
(CSM A and CSM B).

On the path from the Internet to the intranet, traffic enters the insecure side of the firewalls through separate VLANs, VLAN 101 and VLAN 103, and exits the secure side of the firewalls through separate VLANs, VLAN 102 and VLAN 104. On the path from the intranet to the Internet, the flow is reversed. VLANs also provide connectivity to the Internet (VLAN 10) and to the intranet (VLAN 20).

In a stealth configuration, CSM A and CSM B load balance traffic through the firewalls.

Stealth Firewall Configuration Example

The stealth firewall configuration example contains two CSMs (CSM A and CSM B) installed in separate Catalyst 6000 family switches.

Note In a stealth firewall configuration, each CSM must be installed in a separate Catalyst 6000 family switch.

This section describes how to create the stealth firewall configuration for CSM A and CSM B.

Configuring CSM A (Stealth Firewall Example)

Note Although the configuration tasks are the same for both for CSM A and CSM B, the steps, commands, and parameters that you enter are different.

	Command	Purpose
Step 1	`Switch-A(config)# vlan database`	Enters the VLAN mode.¹
Step 2	`Switch-A(vlan)# vlan 10`	Creates VLAN 10².
Step 3	`Switch-A(vlan)# vlan 101`	Creates VLAN 101³.
Step 4	`Switch-A(vlan)# vlan 103`	Creates VLAN 103⁴.


	Command	Purpose
Step 1	`Switch-A(config)# module csm 5`	Enters multiple module configuration mode and specifies that CSM A is installed in slot 5.
Step 2	`Switch-A(config-module-csm)# vlan 10 client`	Specifies VLAN 10 as the VLAN that is being configured, identifies it as a client VLAN, and enters VLAN configuration mode.
Step 3	`Switch-A(config-slb-vlan-client)# ip address 10.0.1.35 255.255.255.0`	Specifies an IP address and netmask for VLAN 10.
Step 4	`Switch-A(config-slb-vlan-client)# alias 10.0.1.30 255.255.255.0`	Specifies an alias IP address and netmask for VLAN 10¹.
Step 5	`Switch-A(config-slb-vlan-client)# exit`	Returns to VLAN configuration mode.
Step 6	`Switch-A(config-module-csm)# vlan 101 server`	Specifies VLAN 101 as the VLAN that is being configured, identifies it as a server VLAN, and enters VLAN configuration mode.
Step 7	`Switch-A(config-slb-vlan-server)# ip address 10.0.101.35 255.255.255.0`	Specifies an IP address and netmask for VLAN 101.
Step 8	`Switch-A(config-slb-vlan-server)# alias 10.0.101.100 255.255.255.0`	Specifies an alias IP address and netmask for VLAN 101 1.
Step 9	`Switch-A(config-slb-vlan-server)# exit`	Returns to VLAN configuration mode.
Step 10	`Switch-A(config-module-csm)# vlan 103 server`	Specifies VLAN 103 as the VLAN that is being configured, identifies it as a server VLAN, and enters VLAN configuration mode.
Step 11	`Switch-A(config-slb-vlan)# ip address 10.0.102.35 255.255.255.0`	Specifies an IP address and netmask for VLAN 103.
Step 12	`Switch-A(config-slb-vlan)# alias 10.0.102.100 255.255.255.0`	Specifies an alias IP address and netmask for VLAN 103 1.

¹This step provides a target for CSM B to use in making a load-balancing decision.

Note

Because the IP addresses of CSM B are listed in the INSIDE-SF server farm as real servers, CSM A will load balance the two firewalls that exist in the path to CSM B.


	Command	Purpose
Step 1	`Switch-A(config)# module csm 5`	Enters multiple module configuration mode and specifies that CSM A is installed in slot 5.
Step 2	`Switch-A(config-module-csm)# serverfarm FORWARD-SF`	Creates and names the FORWARD-SF¹ server farm (actually a forwarding policy) and enters server farm configuration mode.
Step 3	`Switch-A(config-slb-sfarm)# no nat server`	Disables the NAT of server IP addresses and port numbers².
Step 4	`Switch-A(config-slb-sfarm)# predictor forward`	Forwards traffic in accordance with its internal routing tables rather than a load-balancing algorithm.
Step 5	`Switch-A(config-slb-sfarm)# exit`	Returns to multiple module configuration mode.
Step 6	`Switch-A(config-module-csm)# serverfarm TO-INSIDE-SF`	Creates and names the INSIDE-SF³ server farm (that will contain alias IP addresses rather than real servers) and enters server farm configuration mode.
Step 7	`Switch-A(config-slb-sfarm)# no nat server`	Disables the NAT of server IP address and port number⁴.
Step 8	`Switch-A(config-slb-sfarm)# predictor hash address source 255.255.255.255`	Selects a server using a hash value based on the source IP address⁵.
Step 9	`Switch-A(config-slb-sfarm)# real 10.0.101.200`	Identifies the alias IP address of CSM B that lies on the path to Firewall 1 as a real server and enters real server configuration submode.
Step 10	`Switch-A(config-slb-real)# inservice`	Enables the firewall.
Step 11	`Switch-A(config-slb-real)# exit`	Returns to server farm configuration mode.
Step 12	`Switch-A(config-slb-sfarm)# real 10.0.102.200`	Identifies the alias IP address of CSM B that lies on the path to Firewall 2 as a real server and enters real server configuration submode.
Step 13	`Switch-A(config-slb-real)# inservice`	Enables the firewall.

¹FORWARD-SF is actually a route forwarding policy, not an actual server farm, that allows traffic to reach the Internet (through VLAN 10). It does not contain any real servers.

²This step is required when configuring a server farm that contains a forwarding policy rather than real servers.

³INSIDE-SF contains the two alias IP addresses of CSM B listed as real servers that allow traffic from the intranet to reach CSM B.

⁴This step is required when configuring a server farm that contains firewalls.

⁵We recommend this step when configuring insecure-side firewall interfaces in a server farm.


	Command	Purpose
Step 1	`Switch-A(config)# module csm 5`	Enters multiple module configuration mode and specifies that the CSM A is installed in slot 5.
Step 2	`Switch-A(config-module-csm)# vserver FORWARD-V101`	Specifies FORWARD-V101¹ as the virtual server that is being configured and enters virtual server configuration mode.
Step 3	`Switch-A(config-slb-vserver)# virtual 0.0.0.0 0.0.0.0 any`	Specifies a match for any IP address and any protocol².
Step 4	`Switch-A(config-slb-vserver))# vlan 101`	Specifies that the virtual server will only accept traffic arriving on VLAN 101, which is traffic arriving from the insecure side of the firewalls.
Step 5	`Switch-A(config-slb-vserver)# serverfarm FORWARD-SF`	Specifies the server farm for this virtual server³.
Step 6	`Switch-A(config-slb-vserver)# inservice`	Enables the virtual server.
Step 7	`Switch-A(config-slb-vserver)# exit`	Returns to multiple module configuration mode.
Step 8	`Switch-A(config-module-csm)# vserver FORWARD-V103`	Specifies FORWARD-V103⁴ as the virtual server that is being configured and enters virtual server configuration mode.
Step 9	`Switch-A(config-slb-vserver)# virtual 0.0.0.0 0.0.0.0 any`	Specifies a match for any IP address and any protocol⁵.
Step 10	`Switch-A(config-slb-vserver))# vlan 103`	Specifies that the virtual server will only accept traffic arriving on VLAN 103, which is traffic arriving from the insecure side of the firewalls.
Step 11	`Switch-A(config-slb-vserver)# serverfarm FORWARD-SF`	Specifies the server farm for this virtual server 3.
Step 12	`Switch-A(config-slb-vserver)# inservice`	Enables the virtual server.
Step 13	`Switch-A(config-slb-vserver)# exit`	Returns to multiple module configuration mode.
Step 14	`Switch-A(config-module-csm)# vserver OUTSIDE-VS`	Specifies OUTSIDE-VS⁶ as the virtual server that is being configured and enters virtual server configuration mode.
Step 15	`Switch-A(config-slb-vserver)# virtual 10.1.0.0 255.255.255.0 any`	Specifies the IP address, netmask, and protocol (any) for this virtual server. Clients reach the server farm represented by this virtual server through this address.
Step 16	`Switch-A(config-slb-vserver))# vlan 10`	Specifies that the virtual server will only accept traffic arriving on VLAN 10, which is traffic arriving from the Internet.
Step 17	`Switch-A(config-slb-vserver)# serverfarm TO-INSIDE-SF`	Specifies the server farm for this virtual server⁷.
Step 18	`Switch-A(config-slb-vserver)# inservice`	Enables the virtual server.

¹FORWARD-V101 allows Internet traffic to reach the insecure side of the firewalls (through VLAN 101).

²Client matching is only limited by VLAN restrictions (see Step 4).

³This server farm is actually a forwarding predictor rather than an actual server farm containing real servers.

⁴FORWARD-V103 allows Internet traffic to reach the insecure side of the firewalls (through VLAN 103).

⁵Clients will always match-only being limited by VLAN restrictions. (See Step 10.)

⁶OUTSIDE-VS allows traffic from the Internet to reach CSM A (through VLAN 10).

⁷The server farm contains the alias IP addresses of CSM B that lie along the path of Firewall 1 and Firewall 2.

Configuring CSM B (Stealth Firewall Example)

To create the regular configuration example, perform the following configuration tasks for CSM B:

Note Although the configuration tasks are the same for both CSM A and CSM B, the steps, commands, and parameters that you enter are different.

Note This example assumes that the CSMs are in separate Catalyst 6000 family switches. If they are in the same chassis, you can create all of the VLANs on the same Catalyst 6000 family switch console.

	Command	Purpose
Step 1	`Switch-B(config)# vlan database`	Enters the VLAN mode¹.
Step 2	`Switch-B(vlan)# vlan 102`	Creates VLAN 102².
Step 3	`Switch-B(vlan)# vlan 104`	Creates VLAN 104³.
Step 4	`Switch-B(vlan)# vlan 200`	Creates VLAN 200⁴.


	Command	Purpose
Step 1	`Switch-B(config)# module csm 6`	Enters multiple module configuration mode and specifies that CSM B is installed in slot 6.
Step 2	`Switch-B(config-module-csm)# vlan 102 server`	Specifies VLAN 102 as the VLAN that is being configured, identifies it as a server VLAN, and enters VLAN configuration mode.
Step 3	`Switch-B(config-slb-vlan-server)# ip address 10.0.101.36 255.255.255.0`	Specifies an IP address and netmask for VLAN 102.
Step 4	`Switch-B(config-slb-vlan-server)# alias 10.0.101.200 255.255.255.0`	Specifies an alias IP address and netmask for VLAN 102¹.
Step 5	`Switch-B(config-slb-vlan-server)# exit`	Returns to multiple module configuration mode.
Step 6	`Switch-B(config-module-csm)# vlan 104 server`	Specifies VLAN 104 as the VLAN that is being configured, identifies it as a server VLAN, and enters VLAN configuration mode.
Step 7	`Switch-B(config-slb-vlan-server)# ip address 10.0.102.36 255.255.255.0`	Specifies an IP address and netmask for VLAN 104.
Step 8	`Switch-B(config-slb-vlan)# alias 10.0.102.200 255.255.255.0`	Specifies an alias IP address and netmask for VLAN 104 1.
Step 9	`Switch-B(config-slb-vlan-server)# exit`	Returns to multiple module configuration mode.
Step 10	`Switch-B(config-module-csm)# vlan 20 server`	Specifies VLAN 20 as the VLAN that is being configured, identifies it as a server VLAN, and enters VLAN configuration mode.
Step 11	`Switch-B(config-slb-vlan-server)# ip address 10.1.0.36 255.255.255.0`	Specifies an IP address and netmask for VLAN 20.

¹This step provides a target for CSM A to use in making a load-balancing decision.

Note

SERVERS-SF specifies that client NAT will be performed using a pool of client NAT addresses that are created earlier in the example using the natpool command. You must create the NAT pool before referencing the command.


	Command	Purpose
Step 1	`Switch-B(config)# module csm 6`	Enters multiple module configuration mode and specifies that CSM B is installed in slot 6.
Step 2	`Switch-B(config-module-csm)# serverfarm FORWARD-SF`	Creates and names the FORWARD-SF¹ server farm (actually a forwarding policy) and enters server farm configuration mode.
Step 3	`Switch-B(config-slb-sfarm)# no nat server`	Disables the NAT of server IP addresses and port numbers².
Step 4	`Switch-B(config-slb-sfarm)# predictor forward`	Forwards traffic in accordance with its internal routing tables rather than a load-balancing algorithm.
Step 5	`Switch-B(config-slb-sfarm)# exit`	Returns to multiple module configuration mode.
Step 6	`Switch-B(config-module-csm)# serverfarm TO-OUTSIDE-SF`	Creates and names the GENERIC-SF server farm and enters server farm configuration mode³.
Step 7	`Switch-B(config-slb-sfarm)# no nat server`	Disables NAT of server IP addresses and port numbers⁴.
Step 8	`Switch-B(config-slb-sfarm)# real 10.0.101.100`	Identifies the alias IP address of CSM A that lies on the path to Firewall 1 as a real server and enters real server configuration submode.
Step 9	`Switch-B(config-slb-real)# inservice`	Enables the real (actually an alias IP address).
Step 10	`Switch-B(config-slb-real)# exit`	Returns to server farm configuration mode.
Step 11	`Switch-B(config-slb-sfarm)# real 10.0.102.100`	Identifies the alias IP address of CSM B that lies on the path to Firewall 2 as a real server and enters real server configuration submode.
Step 12	`Switch-B(config-slb-real)# inservice`	Enables the real server (actually an alias IP address).
Step 13	`Switch-B(config-slb-real)# exit`	Returns to server farm configuration mode.
Step 14	`Switch-B(config-module-csm)# serverfarm SERVERS-SF`	Creates and names the SERVERS-SF⁵ server farm and enters serverfarm configuration mode.
Step 15	`Switch-B(config-slb-sfarm)# real 10.1.0.101`	Identifies a server in the intranet as a real server, assigns it an IP address, and enters real server configuration submode.
Step 16	`Switch-B(config-slb-real)# inservice`	Enables the real server.
Step 17	`Switch-B(config-slb-real)# exit`	Returns to server farm configuration mode.
Step 18	`Switch-B(config-slb-sfarm)# real 10.1.0.102`	Identifies a server in the intranet as a real server, assigns it an IP address, and enters real server configuration submode.
Step 19	`Switch-B(config-slb-real)# inservice`	Enables the real server.
Step 20	`Switch-B(config-slb-sfarm)# real 10.1.0.103`	Identifies a server in the intranet as a real server, assigns it an IP address, and enters real server configuration submode.
Step 21	`Switch-B(config-slb-real)# inservice`	Enables the real server.

¹FORWARD-SF is actually a route forwarding policy, not an actual server farm, that allows traffic to reach the intranet (through VLAN 20). It does not contain any real servers.

²This is a required step when configuring a server farm that contains a forwarding policy rather than real servers.

³OUTSIDE-SF contains the two alias IP addresses of CSM A as the real servers allowing traffic from the intranet to reach CSM A.

⁴This is a required step when configuring a server farm that contains a forwarding policy rather than real servers.

⁵SERVERS-SF contains the IP addresses of the real servers located within the intranet.


	Command	Purpose
Step 1	`Switch-B(config)# module csm 6`	Enters multiple module configuration mode and specifies that CSM B is installed in slot 6.
Step 2	`Switch-B(config-module-csm)# vserver FORWARD-VS-102`	Specifies FORWARD-VS as the virtual server that is being configured and enters virtual server configuration mode.
Step 3	`Switch-B(config-slb-vserver)# virtual 0.0.0.0 0.0.0.0 any`	Specifies a match for any IP address and any protocol¹.
Step 4	`Switch-B(config-slb-vserver)# vlan 102`	Specifies that the virtual server will only accept traffic arriving on VLAN 102, which is traffic arriving from the secure side of the Firewall 1.
Step 5	`Switch-B(config-slb-vserver)# serverfarm FORWARD-SF`	Specifies the server farm for this virtual server².
Step 6	`Switch-B(config-slb-vserver)# inservice`	Enables the virtual server.
Step 7	`Switch-B(config-slb-vserver)# exit`	Returns to multiple module configuration mode.
Step 8	`Switch-B(config-module-csm)# vserver FORWARD-VS-104`	Specifies FORWARD-VS³ as the virtual server that is being configured and enters virtual server configuration mode.
Step 9	`Switch-B(config-slb-vserver)# virtual 0.0.0.0 0.0.0.0 any`	Specifies a match for any IP address and any protocol 1.
Step 10	`Switch-B(config-slb-vserver)# vlan 104`	Specifies that the virtual server will only accept traffic arriving on VLAN 104, which is traffic arriving from the secure side of the Firewall 2.
Step 11	`Switch-B(config-slb-vserver)# serverfarm FORWARD-SF`	Specifies the server farm for this virtual server 2.
Step 12	`Switch-B(config-slb-vserver)# inservice`	Enables the virtual server.
Step 13	`Switch-B(config-slb-vserver)# exit`	Returns to multiple module configuration mode.
Step 14	`Switch-B(config-module-csm)# vserver INSIDE-VS`	Specifies INSIDE-VS⁴ as the virtual server that is being configured and enters virtual server configuration mode.
Step 15	`Switch-B(config-slb-vserver)# virtual 0.0.0.0 0.0.0.0 any`	Specifies a match for any IP address and any protocol 1.
Step 16	`Switch-B(config-slb-vserver)# vlan 20`	Specifies that the virtual server will only accept traffic arriving on VLAN 20, which is traffic arriving from the intranet.
Step 17	`Switch-B(config-slb-vserver)# serverfarm TO-OUTSIDE-SF`	Specifies the server farm for this virtual server (containing the alias IP addresses of CSM A as real servers and allowing traffic to flow through Firewalls 1 and 2) and enters real server configuration submode.
Step 18	`Switch-B(config-slb-vserver)# inservice`	Enables the virtual server.
Step 19	`Switch-B(config-slb-vserver)# exit`	Returns to multiple module configuration mode.
Step 20	`Switch-B(config-module-csm)# vserver TELNET-VS`	Specifies TELNET-VS⁵ as the virtual server that is being configured and enters virtual server configuration mode. Note TELNET-VS does not use a VLAN limit; any source traffic (from firewalls or internal network) will be load balanced through this address.
Step 21	`Switch-B(config-slb-vserver)# virtual 10.1.0.200 255.255.255.0 tcp telnet`	Specifies the IP address, netmask, protocol (TCP), and port (Telnet) for this virtual server⁶.
Step 22	`Switch-B(config-slb-vserver)# serverfarm SERVERS-SF`	Specifies the server farm containing real servers for this virtual server.
Step 23	`Switch-B(config-slb-vserver)# inservice`	Enables the virtual server.

¹Client matching is only limited by VLAN restrictions.

²This server farm is actually a forwarding predictor rather than an actual server farm containing real servers.

³FORWARD-VS allows traffic from the Internet to reach the intranet through VLAN 20.

⁴INSIDE-VS allows traffic from the intranet to reach CSM A through Firewall 1 (through VLANs 102 and 101) or
Firewall 2 (through VLANs 104 and 103).

⁵TELNET-VS allows traffic from the Internet to reach Telnet servers in the internal network.

⁶Clients reach the server farm represented by this virtual server through this address.

Configuring Regular Firewall Load Balancing

This section describes how to configure firewall load balancing for regular firewalls and provides the following information:

Packet Flow in a Regular Firewall Configuration

In a regular firewall configuration, firewalls connect to two different VLANs and are configured with IP addresses on the VLANs to which they connect. (See Figure 5-7.)

Item	Traffic Direction	Arrives On	Exits On
1	To intranet	VLAN 100	VLANs 101
2	To intranet	VLANs 201	VLAN 200 and 20
3	To Internet	VLAN 200 and 20	VLANs 201
4	To Internet	VLANs 101	VLAN 100

Figure 5-7 shows two regular firewalls (Firewall 1 and Firewall 2) located between two CSMs
(CSM A and CSM B). Traffic enters and exits the firewalls through shared VLANs (VLAN 101 and VLAN 201). Both regular firewalls have unique addresses on each shared VLAN.

VLANs provide connectivity to the Internet (VLAN 100), the internal network (VLAN 200), and to internal server farms (VLAN 20).

The CSM balances traffic among regular firewalls as if they were real servers. Regular firewalls are configured in server farms with IP addresses like real servers. The server farms to which regular firewalls belong are assigned a load-balancing predictor and are associated with virtual servers.

Regular Firewall Configuration Example

The regular firewall configuration example contains two CSMs (CSM A and CSM B) installed in separate Catalyst 6000 family switches.

Note You can use this example when configuring two CSMs in the same Catalyst 6000 family switch chassis. You can also use this example when configuring a single CSM in a single switch chassis, assuming that you specify the slot number of that CSM when configuring both CSM A and CSM B.

Configuring CSM A (Regular Firewall Example)

To create the regular configuration example, perform the following configuration tasks for CSM A:

Note Although the configuration tasks are the same for both CSM A and CSM B, the steps, commands, and parameters that you enter are different.

The example, shown in Figure 5-7, requires that you create two VLANs on Switch A.

Note This example assumes that the CSMs are in separate Catalyst 6000 family switch chassis. If they are in the same chassis, all of the VLANs can be created on the same Catalyst 6000 family switch console.

	Command	Purpose
Step 1	`Switch-A(config)# vlan database`	Enters the VLAN mode¹.
Step 2	`Switch-A(vlan)# vlan 100`	Creates VLAN 100².
Step 3	`Switch-A(vlan)# vlan 101`	Creates VLAN 101³.


	Command	Purpose
Step 1	`Switch-A(config)# module csm 5`	Enters multiple module configuration mode and specifies that CSM A is installed in slot 5.
Step 2	`Switch-A(config-module-csm)# vlan 100 client`	Specifies VLAN 100 as the VLAN that is being configured, identifies it as a client VLAN, and enters VLAN configuration mode.
Step 3	`Switch-A(config-slb-vlan-client)# ip address 100.0.0.25 255.255.255.0`	Specifies an IP address and netmask for VLAN 100.
Step 4	`Switch-A(config-slb-vlan-client)# gateway 100.0.0.13`	Configures a gateway IP address for the router on the Internet side of CSM A.
Step 5	`Switch-A(config-slb-vlan-client)# exit`	Returns to multiple module configuration mode.
Step 6	`Switch-A(config-module-csm)# vlan 101 server`	Specifies VLAN 101 as the VLAN that is being configured, identifies it as a server VLAN, and enters VLAN configuration mode.
Step 7	`Switch-A(config-slb-vlan-server)# ip address 100.0.0.25 255.255.255.0`	Specifies an IP address and netmask for VLAN 101.
Step 8	`Switch-A(config-slb-vlan-server)# alias 100.0.0.20 255.255.255.0`	Specifies an alias IP address and netmask for VLAN 101¹.

¹This step provides a target for CSM B to use in making a load-balancing decision.

Note

Firewall 1 and Firewall 2 secure-side IP addresses are configured as real servers in the SEC-SF server farm associated with CSM B.


	Command	Purpose
Step 1	`Switch-A(config)# module csm 5`	Enters multiple module configuration mode and specifies that CSM A is installed in slot 5.
Step 2	`Switch-A(config-module-csm)# serverfarm FORWARD-SF`	Creates and names the FORWARD-SF¹ server farm (actually a forwarding policy) and enters server farm configuration mode.
Step 3	`Switch-A(config-slb-sfarm)# no nat server`	Disables the NAT of server IP addresses and port numbers².
Step 4	`Switch-A(config-slb-sfarm)# predictor forward`	Forwards traffic by adhering to its internal routing tables rather than a load-balancing algorithm.
Step 5	`Switch-A(config-slb-sfarm)# exit`	Returns to multiple module configuration mode.
Step 6	`Switch-A(config-module-csm)# serverfarm INSEC-SF`	Creates and names the INSEC-SF³ server farm (which will contain firewalls as real servers) and enters server farm configuration mode.
Step 7	`Switch-A(config-slb-sfarm)# no nat server`	Disables the NAT of server IP address and port number⁴.
Step 8	`Switch-A(config-slb-sfarm)# predictor hash address source 255.255.255.255`	Selects a server using a hash value based on the source IP address⁵.
Step 9	`Switch-A(config-slb-sfarm)# real 100.0.0.3`	Identifies Firewall 1 as a real server, assigns an IP address to its insecure side, and enters real server configuration submode.
Step 10	`Switch-A(config-slb-real)# inservice`	Enables the firewall.
Step 11	`Switch-A(config-slb-real)# exit`	Returns to server farm configuration mode.
Step 12	`Switch-A(config-slb-sfarm)# real 100.0.0.4`	Identifies Firewall 2 as a real server, assigns an IP address to its insecure side, and enters real server configuration submode.
Step 13	`Switch-A(config-slb-real)# inservice`	Enables the firewall.

¹FORWARD-SF is actually a route forwarding policy, not an actual server farm, that allows traffic to reach the Internet (through VLAN 100); it does not contain any real servers.

²This is a required step when configuring a server farm that contains a forwarding policy rather than real servers.

³INSEC-SF contains (Firewall 1 and Firewall 2); their insecure-side IP addresses are configured as real servers in this server farm.

⁴This is a required step when configuring a server farm that contains firewalls.

⁵We recommend this step when configuring insecure-side firewall interfaces in a server farm.


	Command	Purpose
Step 1	`Switch-A(config)# module csm 5`	Enters multiple module configuration mode and specifies that the CSM A is installed in slot 5.
Step 2	`Switch-A(config-module-csm)# vserver FORWARD-VS`	Specifies FORWARD-VS¹ as the virtual server that is being configured and enters virtual server configuration mode.
Step 3	`Switch-A(config-slb-vserver)# virtual 0.0.0.0 0.0.0.0 any`	Specifies a match for any IP address and any protocol².
Step 4	`Switch-A(config-slb-vserver))# vlan 101`	Specifies that the virtual server will only accept traffic arriving on VLAN 101, which is traffic arriving from the insecure side of the firewalls.
Step 5	`Switch-A(config-slb-vserver)# serverfarm FORWARD-SF`	Specifies the server farm for this virtual server³.
Step 6	`Switch-A(config-slb-vserver)# inservice`	Enables the virtual server.
Step 7	`Switch-A(config-slb-vserver)# exit`	Returns to multiple module configuration mode.
Step 8	`Switch-A(config-module-csm)# vserver INSEC-VS`	Specifies INSEC-VS⁴ as the virtual server that is being configured and enters virtual server configuration mode.
Step 9	`Switch-A(config-slb-vserver)# virtual 200.0.0.0 255.255.255.0 any`	Specifies the IP address, netmask, and protocol (any) for this virtual server⁵.
Step 10	`Switch-A(config-slb-vserver))# vlan 100`	Specifies that the virtual server will only accept traffic arriving on VLAN 100, which is traffic arriving from the Internet.
Step 11	`Switch-A(config-slb-vserver)# serverfarm INSEC-SF`	Specifies the server farm for this virtual server⁶.
Step 12	`Switch-A(config-slb-vserver)# inservice`	Enables the virtual server.

¹FORWARD-VS allows Internet traffic to reach the insecure side of the firewalls (through VLAN 101).

²Client matching is only limited by VLAN restrictions (see Step 4).

³This server farm is actually a forwarding predictor rather than an actual server farm containing real servers.

⁴INSEC-VS allows traffic from the Internet to reach CSM A (through VLAN 101).

⁵Clients reach the server farm represented by this virtual server through this address.

⁶The server farm contains firewalls rather than real servers.

Configuring CSM B (Regular Firewall Example)

To create the regular configuration example, perform the following configuration tasks for CSM B:

Note Although the configuration tasks are the same for both CSM A and CSM B, the steps, commands, and parameters that you enter are different.

	Command	Purpose
Step 1	`Switch-B(config)# vlan database`	Enters the VLAN mode¹.
Step 2	`Switch-B(vlan)# vlan 201`	Creates VLAN 201².
Step 3	`Switch-B(vlan)# vlan 200`	Creates VLAN 200³.
Step 4	`Switch-B(vlan)# vlan 20`	Creates VLAN 20⁴.


	Command	Purpose
Step 1	`Switch-B(config)# module csm 6`	Enters multiple module configuration mode and specifies that CSM B is installed in slot 6.
Step 2	`Switch-B(config-module-csm)# vlan 201 server`	Specifies VLAN 201 as the VLAN that is being configured, identifies it as a server VLAN, and enters VLAN configuration mode.
Step 3	`Switch-B(config-slb-vlan-server)# ip address 200.0.0.26 255.255.255.0`	Specifies an IP address and netmask for VLAN 201.
Step 4	`Switch-B(config-slb-vlan-server)# alias 200.0.0.20 255.255.255.0`	Specifies an alias IP address and netmask for VLAN 201¹.
Step 5	`Switch-B(config-slb-vlan-server)# exit`	Returns to VLAN configuration mode.
Step 6	`Switch-B(config-module-csm)# vlan 20 server`	Specifies VLAN 20 as the VLAN that is being configured, identifies it as a server VLAN, and enters VLAN configuration mode.
Step 7	`Switch-B(config-slb-vlan-server)# ip address 10.1.0.26 255.255.255.0`	Specifies an IP address and netmask for VLAN 20.
Step 8	`Switch-B(config-slb-vlan-server)# exit`	Returns to VLAN configuration mode.
Step 9	`Switch-B(config-module-csm)# vlan 200 client`	Specifies VLAN 200 as the VLAN that is being configured, identifies it as a client VLAN, and enters VLAN configuration mode.
Step 10	`Switch-B(config-slb-vlan)# ip address 200.0.0.26 255.255.255.0`	Specifies an IP address and netmask for VLAN 200.

¹This step provides a target for CSM A to use in making a load-balancing decision.

Note

Firewall 1 and Firewall 2 secure-side IP addresses are configured as real servers in the INSEC-SF server farm associated with CSM A.


	Command	Purpose
Step 1	`Switch-B(config)# module csm 6`	Enters multiple module configuration mode and specifies that CSM B is installed in slot 6.
Step 2	`Switch-B(config-module-csm)# serverfarm GENERIC-SF`	Creates and names the GENERIC-SF¹ server farm and enters server farm configuration mode.
Step 3	`Switch-B(config-slb-sfarm)# real 10.1.0.101`	Identifies a server in the internal server farm as a real server, assigns it an IP address, and enters real server configuration submode.
Step 4	`Switch-B(config-slb-real)# inservice`	Enables the real server.
Step 5	`Switch-B(config-slb-real)# exit`	Returns to server farm configuration mode.
Step 6	`Switch-B(config-slb-sfarm)# real 10.1.0.102`	Identifies a server in the internal server farm as a real server, assigns it an IP address, and enters real server configuration submode.
Step 7	`Switch-B(config-slb-real)# inservice`	Enables the real server.
Step 8	`Switch-B(config-slb-real)# exit`	Returns to server farm configuration mode.
Step 9	`Switch-B(config-slb-sfarm)# exit`	Returns to multiple module configuration mode.
Step 10	`Switch-B(config-module-csm)# serverfarm SEC-SF`	Creates and names the SEC-SF² server farm and enters server farm configuration mode.
Step 11	`Switch-B(config-slb-sfarm)# no nat server`	Disables the NAT of server IP address and port number³.
Step 12	`Switch-B(config-slb-sfarm)# predictor hash address destination 255.255.255.255`	Selects a server using a hash value based on the destination IP address⁴.
Step 13	`Switch-B(config-slb-sfarm)# real 200.0.0.3`	Identifies Firewall 1 as a real server, assigns an IP address to its insecure side, and enters real server configuration submode.
Step 14	`Switch-B(config-slb-real)# inservice`	Enables the firewall.
Step 15	`Switch-B(config-slb-real)# exit`	Returns to server farm configuration mode.
Step 16	`Switch-B(config-slb-sfarm)# real 200.0.0.4`	Identifies Firewall 2 as a real server, assigns an IP address to its insecure side, and enters real server configuration submode.
Step 17	`Switch-B(config-slb-real)# inservice`	Enables the firewall.

¹GENERIC-SF contains the real servers in the internal server farm.

²SEC-SF contains (firewall 1 and firewall 2)-their secure-side IP addresses are configured as real servers in this server farm.

³This is a required step when configuring a server farm that contains firewalls.

⁴We recommend this step when configuring secure-side firewall interfaces in a server farm.


	Command	Purpose
Step 1	`Switch-B(config)# module csm 6`	Enters multiple module configuration mode and specifies that CSM B is installed in slot 6.
Step 2	`Switch-B(config-module-csm)# vserver GENERIC-VS`	Specifies GENERIC-VS¹ as the virtual server that is being configured and enters virtual server configuration mode.
Step 3	`Switch-B(config-slb-vserver)# virtual 200.0.0.127 tcp 0`	Specifies the IP address, protocol (TCP), and port (0=any) for this virtual server².
Step 4	`Switch-B(config-slb-vserver))# vlan 201`	Specifies that the virtual server will only accept traffic arriving on VLAN 201, which is traffic arriving from the secure side of the firewalls.
Step 5	`Switch-B(config-slb-vserver)# serverfarm GENERIC-SF`	Specifies the server farm for this virtual server³.
Step 6	`Switch-B(config-slb-vserver)# inservice`	Enables the virtual server.
Step 7	`Switch-B(config-slb-vserver)# exit`	Returns to multiple module configuration mode.
Step 8	`Switch-B(config-module-csm)# vserver SEC-20-VS`	Specifies SEC-20-VS⁴ as the virtual server that is being configured and enters virtual server configuration mode.
Step 9	`Switch-B(config-slb-vserver)# virtual 200.0.0.0 255.255.255.0 any`	Specifies the IP address, netmask, and protocol (any) for this virtual server 2.
Step 10	`Switch-B(config-slb-vserver))# vlan 20`	Specifies that the virtual server will only accept traffic arriving on VLAN 20, which is traffic arriving from the internal server farms.
Step 11	`Switch-B(config-slb-vserver)# serverfarm SEC-SF`	Specifies the server farm for this virtual server⁵.
Step 12	`Switch-B(config-slb-vserver)# inservice`	Enables the virtual server.
Step 13	`Switch-B(config-slb-vserver)# exit`	Returns to multiple module configuration mode.
Step 14	`Switch-B(config-module-csm)# vserver SEC-200-VS`	Specifies SEC-20-VS⁶ as the virtual server that is being configured and enters virtual server configuration mode.
Step 15	`Switch-B(config-slb-vserver)# virtual 200.0.0.0 255.255.255.0 any`	Specifies the IP address, netmask, and protocol (any) for this virtual server 2.
Step 16	`Switch-B(config-slb-vserver))# vlan 200`	Specifies that the virtual server will only accept traffic arriving on VLAN 200, which is traffic arriving from the internal network.
Step 17	`Switch-B(config-slb-vserver)# serverfarm SEC-SF`	Specifies the server farm for this virtual server 5.
Step 18	`Switch-B(config-slb-vserver)# inservice`	Enables the virtual server.

¹GENERIC-VS allows traffic from the internal server farms and the internal network that is destined for the Internet to reach the secure side of the firewalls (through VLAN 101).

²Clients reach the server farm represented by this virtual server through this address.

³The server farm exists in the internal server farms network.

⁴SEC-20-VS allows traffic from the Internet to reach the internal server farms (through VLAN 20).

⁵The server farm contains firewalls rather than real servers.

⁶SEC-200-VS allows traffic from the Internet to reach the internal network (through VLAN 20).

Configuring Generic Header Parsing

In software release 2.1(1), the CSM supports generic HTTP request header parsing. The HTTP request header contains fields that describe how content should be formatted to meet the user's requirements.

The CSM uses the information it learns by parsing and matching fields in the HTTP header along with policy information to make load-balancing decisions. For example, by parsing the browser-type field in the HTTP header, the CSM can determine if a user is accessing the content with a mobile browser and can select a server that contains content formatted for a mobile browser.

Configuring Generic Header Parsing

You configure generic header parsing by entering commands that instruct the CSM to perform policy matching on fields in the HTTP header. These sections describe how to configure generic header parsing on the CSM:

Creating a Map for the HTTP Header

Using the map command, you create a map group with the type HTTP header. Entering the map command places you in a submode where you can specify the header fields and values for CSM to search for in the request.

Specifying Header Fields and Match Values

	Command	Purpose
	`Router(config-module-csm)# map name header`	Creates and names a HTTP header map group.

Using the match command, you specify the name of the field and corresponding value for the CSM to match when receiving an HTTP request.

	Command	Purpose
	`Router(config-slb-map-header)# match protocol http header field header-value expression`	Specifies the name of the field and value. The field can be any HTTP header except cookie. You can configure cookie map if you want to configure cookie header.

Note The CSM allows you to specify one or more fields in the HTTP header to be the criteria for policy matching. When multiple fields are configured in a single HTTP header group, all of the expressions in this group must match in order to satisfy this criteria.

Assigning an HTTP Header Map to a Policy

In policy submode, you specify the header map to include in that policy. The header map contains the HTTP header criteria to be included in a policy.

	Command	Purpose
Step 1	`Router(config-module-csm)# policy policy-name`	Creates a policy.
Step 2	`Router(config-slb-policy)# header-map name`	Assigns an HTTP header map to a policy.

Note By default, a policy rule can be satisfied with any HTTP header information. The HTTP URL and HTTP cookie are specific types of header information and are handled separately by the CSM.

Assigning the Policy to a Virtual Server

In virtual server submode, specify the name of the policy that has the header map assigned, using the ip slb vserver virtserver-name command.

Configuring Persistent Connections

The CSM allows HTTP connections to be switched based on a URL, cookies, or other fields contained in the HTTP header. Persistent connection support in the CSM allows for each successive HTTP request in a persistent connection to be switched independently. As a new HTTP request arrives, it may be switched to the same server as the prior request, it may be switched to a different server, or it may be reset to the client preventing that request from being completed.

In software release 2.1(1), the CSM supports HTTP 1.1 persistence. This features allows browsers to send multiple HTTP requests on a single persistent connection. After a persistent connection is established, the server keeps the connection open for a configurable interval, anticipating that it may receive more requests from the same client. Persistent connections eliminate the overhead involved in establishing a new TCP connection for each request.

	Command	Purpose
Step 1	`Router(config-module-csm)# vserver virtserver-name`	Configures a virtual server.
Step 2	Router(config-slb-policy)# header-map name	Assigns an HTTP header map to a policy.

HTTP 1.1 persistence is enabled by default on all virtual servers configured with Layer 7 policies. To disable persistent connections, enter the no persistent rebalance command. To enable persistent connection, enter the persistent rebalance command.

Configuring Connection Redundancy

Connection redundancy prevents open connections from hanging when the active CSM fails and the standby CSM becomes active. With connection redundancy, the active CSM replicates forwarding information to the standby CSM for each connection that is to remain open when the active CSM fails over to the standby CSM.


	Command	Purpose
Step 1	`Router(config-module-csm)# vserver virtserver-name`	Identifies a virtual server and enters the vserver submode.
Step 2	`Router(config-slb-vserver)# virtual ip-address [ip-mask] protocol port-number [service ftp]`	Configures the virtual server attributes.
Step 3	`Router(config-slb-vserver)# serverfarm serverfarm-name`	Associates a server farm with a virtual server.
Step 4	`Router(config-slb-vserver)# sticky duration [group group-id] [netmask ip-netmask]`	Ensures that connections from the same client use the same real server.
Step 5	`Router(config-slb-vserver)# replicate csrp sticky`	Enables sticky replication.
Step 6	`Router(config-slb-vserver)# replicate csrp connection`	Enables connection replication.
Step 7	`Router(config-slb-vserver)# inservice`	Enables the virtual server for load balancing.
Step 8	`Router(config-module-csm)# ft group group-id vlan vlanid`	Configures fault tolerance and enters the fault-tolerance submode.
Step 9	`Router(config-slb-ft)# priority value`	Sets the priority of the CSM.
Step 10	`Router(config-slb-ft)# failover failover-time`	Sets the time for a standby CSM to wait before becoming an active CSM.
Step 11	`Router(config-slb-ft)# preempt`	Allows a higher priority CSM to take control of a fault-tolerant group when it comes online.

Configuring a Hitless Upgrade

A hitless upgrade allows you to upgrade to a new version without any major service disruption due to the downtime for the upgrade. To configure a hitless upgrade, perform these steps:

Step 3

Upgrade the standby system with the new release, and then reboot the CSM.

The standby CSM boots as standby with the new release. If you have sticky backup enabled, keep the standby CSM in standby mode for at least 5 minutes.

When the active CSM reboots, the standby CSM becomes the new active CSM and takes over the service responsibility.

Configuring SNMP Traps for Real Servers

When enabled, an SNMP trap is sent to an external management device each time a real server changes its state (for example, each time a server is taken in or out of service). The trap contains an Object Identifier (OID) that identifies it as a real-server trap.

The trap also contains a message describing the reason for the server state change.

	Command	Purpose
Step 1	`Router (config)# snmp-server community public`	Defines a password-like community string sent with the notification operation. The example string is public.
Step 2	`Router (config)# snmp-server host host-addr`	Defines the IP address of an external network management device to which traps are sent.
Step 3	`Router (config)# snmp-server enable traps`	Enables SNMP traps for real servers.

Table Of Contents

Configuring Advanced Server Load Balancing

Configuring URL Hashing

Configuring a URL Hashing Predictor

Configuring Beginning and Ending Patterns

Configuring Firewall Load Balancing

Understanding How Firewalls Work

Firewalls Types

How the CSM Distributes Traffic to Firewalls

Supported Firewalls

Layer 3 Load Balancing to Firewalls

Types of Firewall Configurations

CSM Firewall Configurations

Fault-Tolerant CSM Firewall Configurations

Configuring Stealth Firewall Load Balancing

Stealth Firewall Configuration

Stealth Firewall Configuration Example

Configuring CSM A (Stealth Firewall Example)

Configuring CSM B (Stealth Firewall Example)

Configuring Regular Firewall Load Balancing

Packet Flow in a Regular Firewall Configuration

Regular Firewall Configuration Example

Configuring CSM A (Regular Firewall Example)

Configuring CSM B (Regular Firewall Example)

Configuring Generic Header Parsing

Configuring Generic Header Parsing

Creating a Map for the HTTP Header

Specifying Header Fields and Match Values

Assigning an HTTP Header Map to a Policy

Assigning the Policy to a Virtual Server

Configuring Persistent Connections

Configuring Connection Redundancy

Configuring a Hitless Upgrade

Configuring SNMP Traps for Real Servers