- Preface
- Product Overiew
- Networking with the Content Switching Module
- Getting Started
- Configuring VLANs
- Configuring Real Servers and Server Farms
- Configuring Virtual Servers, Maps, and Policies
- Configuring Redundant Connections
- Configuring Additional Features and Options
- Configuring Health Monitoring
- Configuring CSM Scripts
- Configuring Firewall Load Balancing
- Configuration Examples
- Troubleshooting and System Messages
- CSM XML Document Type Definition
- Configuring the Router Mode with the MSFC on the Client Side
- Configuring the Bridged Mode with the MSFC on the Client Side
- Configuring the Probes
- Configuring the Source NAT for Server-Originated Connections to the VIP
- Configuring Session Persistence (Stickiness)
- Configuring Direct Access to Servers in Router Mode
- Configuring Server-to-Server Load Balanced Connections
- Configuring Route Health Injection
- Configuring the Server Names
- Configuring a Backup Server Farm
- Configuring Load-balancing Decisions Based on the Source IP Address
- Configuring Layer 7 Load Balancing
- Configuring HTTP Redirect
Configuration Examples
Each example in this appendix includes only the relevant portions of the configuration. In some cases, some portions of the Layer 2 and Layer 3 Catalyst switch configuration are included. Lines with comments start with # and can be pasted in the configuration once you are in configuration mode after entering the configuration terminal command.
Make sure that you create all the VLANs used in the CSM configuration on the switch using the vlan command.
Configuring the Router Mode with the MSFC on the Client Side
This example provides configuration parameters for setting up the router mode:
module ContentSwitchingModule 5
vlan 220 server
ip address 10.20.220.2 255.255.255.0
alias 10.20.220.1 255.255.255.0
# The servers' default gateway is the alias IP address
# Alias IP addresses are needed any time that you are
# configuring a redundant system.
# However, it is a good practice to always use a
# alias IP address so that a standby CSM can easily
# be added without changes to the IP addressing scheme
!
vlan 221 client
ip address 10.20.221.5 255.255.255.0
gateway 10.20.221.1
# The CSM default gateway in this config is the
# MSFC IP address on that VLAN
!
serverfarm WEBFARM
nat server
no nat client
real 10.20.220.10
inservice
real 10.20.220.20
inservice
real 10.20.220.30
no inservice
!
vserver WEB
virtual 10.20.221.100 tcp www
serverfarm WEBFARM
persistent rebalance
inservice
# "persistence rebalance" is effective ONLY when performing
# L7 load balancing (parsing of URLs, cookies, header, ...)
# and only for HTTP 1.1 connections.
# It tells the CSM to parse and eventually make a new
# load balancing decision for each GET within the same
# TCP connection.
interface FastEthernet2/2
no ip address
switchport
switchport access vlan 220
# The above is the port that connects to the real servers
interface FastEthernet2/24
ip address 10.20.1.1 255.255.255.0
# The above is the interface that connects to the client side network
interface Vlan221
ip address 10.20.221.1 255.255.255.0
# The above is the MSFC interface for the internal VLAN used
# for MSFC-CSM communication
Output of show commands:
Cat6k-2# show module csm 5 arp
Internet Address Physical Interface VLAN Type Status
--------------------------------------------------------------------
10.20.220.1 00-02-FC-E1-68-EB 220 -ALIAS- local
10.20.220.2 00-02-FC-E1-68-EC 220 --SLB-- local
10.20.220.10 00-D0-B7-A0-81-D8 220 REAL up(0 misses)
10.20.221.1 00-02-FC-CB-70-0A 221 GATEWAY up(0 misses)
10.20.221.5 00-02-FC-E1-68-EC 221 --SLB-- local
10.20.220.20 00-D0-B7-A0-81-D8 220 REAL up(0 misses)
10.20.220.30 00-D0-B7-A0-81-D8 220 REAL up(0 misses)
10.20.221.100 00-02-FC-E1-68-EB 0 VSERVER local
Cat6k-2# show module csm 5 vlan detail
vlan IP address IP mask type
---------------------------------------------------
220 10.20.220.2 255.255.255.0 SERVER
ALIASES
IP address IP mask
--------------------------------
10.20.220.1 255.255.255.0
221 10.20.221.5 255.255.255.0 CLIENT
GATEWAYS
10.20.221.1
Cat6k-2#
Cat6k-2# show module csm 5 real
real server farm weight state conns/hits
-------------------------------------------------------------------------
10.20.220.10 WEBFARM 8 OPERATIONAL 0
10.20.220.20 WEBFARM 8 OPERATIONAL 0
10.20.220.30 WEBFARM 8 OUTOFSERVICE 0
Cat6k-2#
Cat6k-2# show module csm 5 real detail
10.20.220.10, WEBFARM, state = OPERATIONAL
conns = 0, maxconns = 4294967295, minconns = 0
weight = 8, weight(admin) = 8, metric = 0, remainder = 0
total conns established = 5, total conn failures = 0
10.20.220.20, WEBFARM, state = OPERATIONAL
conns = 0, maxconns = 4294967295, minconns = 0
weight = 8, weight(admin) = 8, metric = 0, remainder = 0
total conns established = 5, total conn failures = 0
10.20.220.30, WEBFARM, state = OUTOFSERVICE
conns = 0, maxconns = 4294967295, minconns = 0
weight = 8, weight(admin) = 8, metric = 0, remainder = 0
total conns established = 0, total conn failures = 0
Cat6k-2#
Cat6k-2# show module csm 5 vserver detail
WEB, type = SLB, state = OPERATIONAL, v_index = 17
virtual = 10.20.221.100/32:80 bidir, TCP, service = NONE, advertise = FALSE
idle = 3600, replicate csrp = none, vlan = ALL, pending = 30, layer 4
max parse len = 2000, persist rebalance = TRUE
ssl sticky offset = 0, length = 32
conns = 0, total conns = 10
Default policy:
server farm = WEBFARM, backup = <not assigned>
sticky: timer = 0, subnet = 0.0.0.0, group id = 0
Policy Tot matches Client pkts Server pkts
-----------------------------------------------------
(default) 10 50 50
Cat6k-2#
Cat6k-2# show module csm 5 stats
Connections Created: 28
Connections Destroyed: 28
Connections Current: 0
Connections Timed-Out: 0
Connections Failed: 0
Server initiated Connections:
Created: 0, Current: 0, Failed: 0
L4 Load-Balanced Decisions: 27
L4 Rejected Connections: 1
L7 Load-Balanced Decisions: 0
L7 Rejected Connections:
Total: 0, Parser: 0,
Reached max parse len: 0, Cookie out of mem: 0,
Cfg version mismatch: 0, Bad SSL2 format: 0
L4/L7 Rejected Connections:
No policy: 1, No policy match 0,
No real: 0, ACL denied 0,
Server initiated: 0
Checksum Failures: IP: 0, TCP: 0
Redirect Connections: 0, Redirect Dropped: 0
FTP Connections: 0
MAC Frames:
Tx: Unicast: 345, Multicast: 5, Broadcast: 25844,
Underflow Errors: 0
Rx: Unicast: 1841, Multicast: 448118, Broadcast: 17,
Overflow Errors: 0, CRC Errors: 0
Configuring the Bridged Mode with the MSFC on the Client Side
This example provides configuration parameters for configuring bridged mode:
module ContentSwitchingModule 5
vlan 221 client
ip address 10.20.220.2 255.255.255.0
gateway 10.20.220.1
!
vlan 220 server
ip address 10.20.220.2 255.255.255.0
# Two VLANs with the same IP address are bridged together.
!
serverfarm WEBFARM
nat server
no nat client
real 10.20.220.10
inservice
real 10.20.220.20
inservice
real 10.20.220.30
no inservice
!
vserver WEB
virtual 10.20.220.100 tcp www
serverfarm WEBFARM
persistent rebalance
inservice
interface FastEthernet2/2
no ip address
switchport
switchport access vlan 220
# The above is the port that connects to the real servers
interface FastEthernet2/24
ip address 10.20.1.1 255.255.255.0
# The above is the MSFC interface that connects to the client side network
interface Vlan221
ip address 10.20.220.1 255.255.255.0
# The above is the MSFC interface for the internal VLAN used
# for MSFC-CSM communication.
# The servers use this IP address as their default gateway
# since the CSM is bridging between the client and server VLANs
Output of show commands:
Cat6k-2# show module csm 5 arp
Internet Address Physical Interface VLAN Type Status
--------------------------------------------------------------------
10.20.220.1 00-02-FC-CB-70-0A 221 GATEWAY up(0 misses)
10.20.220.2 00-02-FC-E1-68-EC 221/220 --SLB-- local
10.20.220.10 00-D0-B7-A0-81-D8 220 REAL up(0 misses)
10.20.220.20 00-D0-B7-A0-81-D8 220 REAL up(0 misses)
10.20.220.30 00-D0-B7-A0-81-D8 220 REAL up(0 misses)
10.20.220.100 00-02-FC-E1-68-EB 0 VSERVER local
Configuring the Probes
This example provides configuration parameters for configuring probes:
module ContentSwitchingModule 5
vlan 220 server
ip address 10.20.220.2 255.255.255.0
alias 10.20.220.1 255.255.255.0
!
vlan 221 client
ip address 10.20.221.5 255.255.255.0
gateway 10.20.221.1
!
probe PING icmp
interval 5
failed 10
receive 4
# Interval between the probes is 5 seconds for healthy servers
# while it is 10 seconds for failed servers.
# The servers need to reply within 4 seconds.
!
probe TCP tcp
interval 5
failed 10
open 4
# The servers need to open the TCP connection within 4 seconds.
!
probe HTTP http
request method head url /probe/http_probe.html
expect status 200 299
interval 20
port 80
# The port for the probe is inherited from the vservers.
# The port is necessary in this case, since the same farm
# is serving a vserver on port 80 and one on port 23.
# If the "port 80" parameter is removed, the HTTP probe
# will be sent out on both ports 80 and 23, thus failing
# on port 23 which does not serve HTTP requests.
probe PING-SERVER-30 icmp
interval 5
failed 10
!
serverfarm WEBFARM
nat server
no nat client
real 10.20.220.10
inservice
real 10.20.220.20
inservice
real 10.20.220.30
health probe PING-SERVER-30
inservice
probe PING
probe TCP
probe HTTP
!
vserver TELNET
virtual 10.20.221.100 tcp telnet
serverfarm WEBFARM
persistent rebalance
inservice
!
vserver WEB
virtual 10.20.221.100 tcp www
serverfarm WEBFARM
persistent rebalance
inservice
!
Output of show commands:
Cat6k-2# show module csm 5 probe
probe type port interval retries failed open receive
---------------------------------------------------------------------
PING icmp 5 3 10 4
TCP tcp 5 3 10 4
HTTP http 80 20 3 300 10 10
PING-SERVER-30 icmp 5 3 10 10
Cat6k-2# show module csm 5 probe detail
probe type port interval retries failed open receive
---------------------------------------------------------------------
PING icmp 5 3 10 4
real vserver serverfarm policy status
------------------------------------------------------------------------------
10.20.220.30:80 WEB WEBFARM (default) OPERABLE
10.20.220.20:80 WEB WEBFARM (default) OPERABLE
10.20.220.10:80 WEB WEBFARM (default) OPERABLE
10.20.220.30:23 TELNET WEBFARM (default) OPERABLE
10.20.220.20:23 TELNET WEBFARM (default) OPERABLE
10.20.220.10:23 TELNET WEBFARM (default) OPERABLE
TCP tcp 5 3 10 4
real vserver serverfarm policy status
------------------------------------------------------------------------------
10.20.220.30:80 WEB WEBFARM (default) OPERABLE
10.20.220.20:80 WEB WEBFARM (default) OPERABLE
10.20.220.10:80 WEB WEBFARM (default) OPERABLE
10.20.220.30:23 TELNET WEBFARM (default) OPERABLE
10.20.220.20:23 TELNET WEBFARM (default) OPERABLE
10.20.220.10:23 TELNET WEBFARM (default) OPERABLE
HTTP http 80 20 3 300 10 10
Probe Request: HEAD /probe/http_probe.html
Expected Status Codes:
200 to 299
real vserver serverfarm policy status
------------------------------------------------------------------------------
10.20.220.30:80 WEB WEBFARM (default) OPERABLE
10.20.220.20:80 WEB WEBFARM (default) FAILED
10.20.220.10:80 WEB WEBFARM (default) OPERABLE
10.20.220.30:80 TELNET WEBFARM (default) OPERABLE
10.20.220.20:80 TELNET WEBFARM (default) FAILED
10.20.220.10:80 TELNET WEBFARM (default) OPERABLE
PING-SERVER-30 icmp 5 3 10 10
real vserver serverfarm policy status
------------------------------------------------------------------------------
10.20.220.30:80 WEB WEBFARM (default) OPERABLE
10.20.220.30:23 TELNET WEBFARM (default) OPERABLE
Cat6k-2# show module csm 5 real
real server farm weight state conns/hits
-------------------------------------------------------------------------
10.20.220.10 WEBFARM 8 OPERATIONAL 0
10.20.220.20 WEBFARM 8 PROBE_FAILED 0
10.20.220.30 WEBFARM 8 OPERATIONAL 0
Configuring the Source NAT for Server-Originated Connections to the VIP
This example shows a situation in which the servers have open connections to the same VIP address that clients access. Because the servers are balanced back to themselves, source NAT is required. To set the source NAT, use the vlan parameter in the virtual server configuration to distinguish the VLAN where the connection is originated. A different server farm is then used to handle server-originated connections. souce NAT is configured for that server farm. No source NAT is used for client-originated connections so that the servers can log the real client IP addresses.
Note 
A very similar configuration needs be used any time that server-to-server load-balanced connections need to be supported with the source and destination servers located in the same VLAN.
module ContentSwitchingModule 5
vlan 220 server
ip address 10.20.220.2 255.255.255.0
alias 10.20.220.1 255.255.255.0
!
vlan 221 client
ip address 10.20.221.5 255.255.255.0
gateway 10.20.221.1
!
natpool POOL-1 10.20.220.99 10.20.220.99 netmask 255.255.255.0
!
serverfarm FARM
nat server
no nat client
real 10.20.220.10
inservice
real 10.20.220.20
inservice
real 10.20.220.30
inservice
!
serverfarm FARM2
nat server
nat client POOL-1
real 10.20.220.10
inservice
real 10.20.220.20
inservice
real 10.20.220.30
inservice
!
vserver FROM-CLIENTS
virtual 10.20.221.100 tcp telnet
vlan 221
serverfarm FARM
persistent rebalance
inservice
!
vserver FROM-SERVERS
virtual 10.20.221.100 tcp telnet
vlan 220
serverfarm FARM2
persistent rebalance
inservice
Output of show commands:
Cat6k-2# show module csm 5 vser
vserver type prot virtual vlan state conns
---------------------------------------------------------------------------
FROM-CLIENTS SLB TCP 10.20.221.100/32:23 221 OPERATIONAL 1
FROM-SERVERS SLB TCP 10.20.221.100/32:23 220 OPERATIONAL 1
Cat6k-2# show module csm 5 conn detail
prot vlan source destination state
----------------------------------------------------------------------
In TCP 220 10.20.220.10:32858 10.20.221.100:23 ESTAB
Out TCP 220 10.20.220.20:23 10.20.220.99:8193 ESTAB
vs = FROM-SERVERS, ftp = No, csrp = False
In TCP 221 10.20.1.100:42443 10.20.221.100:23 ESTAB
Out TCP 220 10.20.220.10:23 10.20.1.100:42443 ESTAB
vs = FROM-CLIENTS, ftp = No, csrp = False
# The command shows the open connections and how they are translated.
#
# For each connection, both halves of the connection are shown.
# The output for the second half of each connection
# swaps the source and destination IP:port.
#
# The connection originated by server 10.20.220.10 is source-NAT'ed
# and source-PAT'ed (also its L4 source port needs to be translated)
# Its source IP changes from 10.20.220.10 to 10.20.220.99
# Its source L4 port changes from 32858 to 8193
Cat6k-2# show module csm 5 real
real server farm weight state conns/hits
-------------------------------------------------------------------------
10.20.220.10 FARM 8 OPERATIONAL 1
10.20.220.20 FARM 8 OPERATIONAL 0
10.20.220.30 FARM 8 OPERATIONAL 0
10.20.220.10 FARM2 8 OPERATIONAL 0
10.20.220.20 FARM2 8 OPERATIONAL 1
10.20.220.30 FARM2 8 OPERATIONAL 0
Cat6k-2# show module csm 5 natpool
nat client POOL-1 10.20.220.99 10.20.220.99 netmask 255.255.255.0
Cat6k-2# show module csm 5 serverfarm
server farm type predictor nat reals redirect bind id
----------------------------------------------------------------------
FARM SLB RoundRobin S 3 0 0
FARM2 SLB RoundRobin S,C 3 0 0
Configuring Session Persistence (Stickiness)
This example provides configuration parameters for configuring session persistence or stickiness:
module ContentSwitchingModule 5
vlan 220 server
ip address 10.20.220.2 255.255.255.0
alias 10.20.220.1 255.255.255.0
!
vlan 221 client
ip address 10.20.221.5 255.255.255.0
gateway 10.20.221.1
!
serverfarm WEBFARM
nat server
no nat client
real 10.20.220.10
inservice
real 10.20.220.20
inservice
real 10.20.220.30
inservice
!
sticky 10 netmask 255.255.255.255 timeout 20
!
sticky 20 cookie yourname timeout 30
!
vserver TELNET
virtual 10.20.221.100 tcp telnet
serverfarm WEBFARM
persistent rebalance
inservice
!
vserver WEB1
virtual 10.20.221.101 tcp www
serverfarm WEBFARM
sticky 20 group 10
persistent rebalance
inservice
!
vserver WEB2
virtual 10.20.221.102 tcp www
serverfarm WEBFARM
sticky 30 group 20
persistent rebalance
inservice
!
Output of show commands:
Cat6k-2# show module csm 5 sticky group 10
group sticky-data real timeout
----------------------------------------------------------------
10 ip 10.20.1.100 10.20.220.10 793
Cat6k-2# show module csm 5 sticky group 20
group sticky-data real timeout
----------------------------------------------------------------
20 cookie 4C656B72:861F0395 10.20.220.20 1597
Cat6k-2# show module csm 5 sticky
group sticky-data real timeout
----------------------------------------------------------------
20 cookie 4C656B72:861F0395 10.20.220.20 1584
10 ip 10.20.1.100 10.20.220.10 778
Configuring Direct Access to Servers in Router Mode
This example shows how to configure a virtual server to give direct access to the back-end servers when you are using router mode:
Note In router mode, any connection that does not hit a virtual server is dropped.
module ContentSwitchingModule 5
vlan 220 server
ip address 10.20.220.2 255.255.255.0
alias 10.20.220.1 255.255.255.0
!
vlan 221 client
ip address 10.20.221.5 255.255.255.0
gateway 10.20.221.1
alias 10.20.221.2 255.255.255.0
# The alias IP is only required in redundant configurations
# This is the IP address that the upstream router (the MSFC
# in this case) will use as next-hop to reach the
# backend servers
# See below for the static route added for this purpose.
#
!
serverfarm ROUTE
no nat server
no nat client
predictor forward
#
# This serverfarm is not load balancing, but is simply
# routing the traffic according to the CSM routing tables
# The CSM routing table in this example is very simple,
# there is just a default gateway and 2 directly attached
# subnets.
#
# The "no nat server" is very important, since you do not
# want to rewrite the destination IP address when
# forwarding the traffic.
!
serverfarm WEBFARM
nat server
no nat client
real 10.20.220.10
inservice
real 10.20.220.20
inservice
!
vserver DIRECT-ACCESS
virtual 10.20.220.0 255.255.255.0 tcp 0
serverfarm ROUTE
persistent rebalance
inservice
# This vserver is listening to all TCP connections destined to the
# serverfarm IP subnet.
# Note: ping to the backend servers will not work with this example
!
vserver WEB
virtual 10.20.221.100 tcp www
serverfarm WEBFARM
persistent rebalance
inservice
interface Vlan221
ip address 10.20.221.1 255.255.255.0
# vlan221 is the L3 interface on the MSFC that connects to the CSM
# Client requests are being routed by the MSFC, from its other
# interfaces (not shown in this example) to vlan221.
!
ip classless
ip route 10.20.220.0 255.255.255.0 10.20.221.2
# This static route is necessary to allow the MSFC to reach
# the backend servers.
Output of some show commands:
Cat6k-2# show module csm 5 conn detail
prot vlan source destination state
----------------------------------------------------------------------
In TCP 221 10.20.1.100:44268 10.20.220.10:23 ESTAB
Out TCP 220 10.20.220.10:23 10.20.1.100:44268 ESTAB
vs = DIRECT-ACCESS, ftp = No, csrp = False
# The information displayed shows that the CSM is not rewriting any IP addresses while
# forwarding theconnection from VLAN 221 (client) to VLAN 220 (server) This connection has
# been created because it was destined to the virtual server DIRECT-ACCESS.
Cat6k-2# show module csm 5 vserver detail
WEB, type = SLB, state = OPERATIONAL, v_index = 14
virtual = 10.20.221.100/32:80 bidir, TCP, service = NONE, advertise = FALSE
idle = 3600, replicate csrp = none, vlan = ALL, pending = 30, layer 4
max parse len = 2000, persist rebalance = TRUE
ssl sticky offset = 0, length = 32
conns = 0, total conns = 0
Default policy:
server farm = WEBFARM, backup = <not assigned>
sticky: timer = 0, subnet = 0.0.0.0, group id = 0
Policy Tot matches Client pkts Server pkts
-----------------------------------------------------
(default) 0 0 0
DIRECT-ACCESS, type = SLB, state = OPERATIONAL, v_index = 15
virtual = 10.20.220.0/24:0 bidir, TCP, service = NONE, advertise = FALSE
idle = 3600, replicate csrp = none, vlan = ALL, pending = 30, layer 4
max parse len = 2000, persist rebalance = TRUE
ssl sticky offset = 0, length = 32
conns = 1, total conns = 1
Default policy:
server farm = ROUTE, backup = <not assigned>
sticky: timer = 0, subnet = 0.0.0.0, group id = 0
Policy Tot matches Client pkts Server pkts
-----------------------------------------------------
(default) 1 48 35
Configuring Server-to-Server Load Balanced Connections
This example shows a CSM configuration with three VLANs, one client, and two server VLANs. This configuration allows server-to-server load-balanced connections. There is no need for the source NAT since the source and destination servers are in separate VLANs.
module ContentSwitchingModule 5
vlan 220 server
ip address 10.20.220.2 255.255.255.0
alias 10.20.220.1 255.255.255.0
!
vlan 221 client
ip address 10.20.221.5 255.255.255.0
gateway 10.20.221.1
!
vlan 210 server
ip address 10.20.210.2 255.255.255.0
alias 10.20.210.1 255.255.255.0
!
serverfarm TIER-1
nat server
no nat client
real 10.20.210.10
inservice
real 10.20.210.20
inservice
!
serverfarm TIER-2
nat server
no nat client
real 10.20.220.10
inservice
real 10.20.220.20
inservice
!
vserver VIP1
virtual 10.20.221.100 tcp telnet
vlan 221
serverfarm TIER-1
persistent rebalance
inservice
!
vserver VIP2
virtual 10.20.210.100 tcp telnet
vlan 210
serverfarm TIER-2
persistent rebalance
inservice
!
Output of some show commands:
Cat6k-2# show module csm 5 arp
Internet Address Physical Interface VLAN Type Status
--------------------------------------------------------------------
10.20.210.1 00-02-FC-E1-68-EB 210 -ALIAS- local
10.20.210.2 00-02-FC-E1-68-EC 210 --SLB-- local
10.20.210.10 00-D0-B7-A0-68-5D 210 REAL up(0 misses)
10.20.210.20 00-D0-B7-A0-68-5D 210 REAL up(0 misses)
10.20.220.1 00-02-FC-E1-68-EB 220 -ALIAS- local
10.20.220.2 00-02-FC-E1-68-EC 220 --SLB-- local
10.20.210.100 00-02-FC-E1-68-EB 0 VSERVER local
10.20.220.10 00-D0-B7-A0-81-D8 220 REAL up(0 misses)
10.20.221.1 00-02-FC-CB-70-0A 221 GATEWAY up(0 misses)
10.20.221.5 00-02-FC-E1-68-EC 221 --SLB-- local
10.20.220.20 00-D0-B7-A0-81-D8 220 REAL up(0 misses)
10.20.221.100 00-02-FC-E1-68-EB 0 VSERVER local
Cat6k-2# show module csm 5 vser
vserver type prot virtual vlan state conns
---------------------------------------------------------------------------
VIP1 SLB TCP 10.20.221.100/32:23 221 OPERATIONAL 1
VIP2 SLB TCP 10.20.210.100/32:23 210 OPERATIONAL 1
Cat6k-2# show module csm 5 conn detail
prot vlan source destination state
----------------------------------------------------------------------
In TCP 221 10.20.1.100:44240 10.20.221.100:23 ESTAB
Out TCP 210 10.20.210.10:23 10.20.1.100:44240 ESTAB
vs = VIP1, ftp = No, csrp = False
In TCP 210 10.20.210.10:45885 10.20.210.100:23 ESTAB
Out TCP 220 10.20.220.10:23 10.20.210.10:45885 ESTAB
vs = VIP2, ftp = No, csrp = False
# The previous command shows a connection opened from a client coming in from VLAN 221
# (client is 10.20.1.100). That connection goes to virtual IP address 1 (VIP1) and is
# balanced to 10.20.210.10. Another connection is opened from server 10.20.210.10, goes to
# VIP2 and is balanced to 10.20.220.10
Configuring Route Health Injection
The CSM supports virtual servers in any IP subnet. If a virtual server is configured in a subnet that is not directly attached to the MSFC, you can configure the CSM to inject a static route into the MSFC routing tables, depending on the health of the server farm serving that virtual server.
You can use this mechanism also for disaster recovery or GSLB solutions, where two distinct CSMs inject a static route for the same VIP. The static routes can then be redistributed, eventually with different costs, to a specific location.
module ContentSwitchingModule 5
vlan 220 server
ip address 10.20.220.2 255.255.255.0
alias 10.20.220.1 255.255.255.0
!
vlan 221 client
ip address 10.20.221.5 255.255.255.0
gateway 10.20.221.1
alias 10.20.221.2 255.255.255.0
The alias IP is very important because it is the IP that the CSM instructs the MSFC to use as the next hop to reach the advertised virtual server.
!
probe PING icmp
interval 2
retries 2
failed 10
receive 2
!
serverfarm WEBFARM
nat server
no nat client
real 10.20.220.10
inservice
real 10.20.220.20
inservice
probe PING
!
vserver WEB
virtual 10.20.250.100 tcp www
vlan 221
# By default, a virtual server listens to traffic coming in on any VLAN. You can restrict
# access to a virtual server by defining a specific VLAN. When using Route Health
# Injection, it is required to specify the VLAN for the virtual server. This tells the CSM
# which next-hop it needs to program in the static route that it will inject in the MSFC
# routing tables.
serverfarm WEBFARM
advertise active
# This is the command that tells the CSM to inject the route for this virtual server. The
# option "active" tells the CSM to remove the route if the backend serverfarm fails.
persistent rebalance
inservice
Output of some show commands:
Cat6k-2# show module csm 5 probe detail
probe type port interval retries failed open receive
---------------------------------------------------------------------
PING icmp 2 2 10 2
real vserver serverfarm policy status
------------------------------------------------------------------------------
10.20.220.20:80 WEB WEBFARM (default) OPERABLE
10.20.220.10:80 WEB WEBFARM (default) OPERABLE
Cat6k-2# show ip route
Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS inter area
* - candidate default, U - per-user static route, o - ODR
P - periodic downloaded static route
Gateway of last resort is 10.20.1.100 to network 0.0.0.0
10.0.0.0/8 is variably subnetted, 8 subnets, 3 masks
C 10.21.1.0/24 is directly connected, Vlan21
S 10.20.250.100/32 [1/0] via 10.20.221.2, Vlan221
# The static route to 10.20.250.100 has been automatically created by the CSM, since both
# servers were healthy.
C 10.20.221.0/24 is directly connected, Vlan221
S* 0.0.0.0/0 [1/0] via 10.30.1.100
Cat6k-2# show module csm 5 vser detail
WEB, type = SLB, state = OPERATIONAL, v_index = 14
virtual = 10.20.250.100/32:80 bidir, TCP, service = NONE, advertise = TRUE
idle = 3600, replicate csrp = none, vlan = 221, pending = 30, layer 4
max parse len = 2000, persist rebalance = TRUE
ssl sticky offset = 0, length = 32
conns = 0, total conns = 6
Default policy:
server farm = WEBFARM, backup = <not assigned>
sticky: timer = 0, subnet = 0.0.0.0, group id = 0
Policy Tot matches Client pkts Server pkts
-----------------------------------------------------
(default) 6 36 30
# Failing the servers causes the route to be removed This behaviour is configured with the
# advertise active command.
Cat6k-2# show module csm 5 probe detail
1d20h: %SYS-5-CONFIG_I: Configured from console by vty0 (probe detail
probe type port interval retries failed open receive
---------------------------------------------------------------------
PING icmp 2 2 10 2
real vserver serverfarm policy status
------------------------------------------------------------------------------
10.20.220.20:80 WEB WEBFARM (default) TESTING
10.20.220.10:80 WEB WEBFARM (default) TESTING
Cat6k-2#
1d20h: %CSM_SLB-6-RSERVERSTATE: Module 5 server state changed: SLB-NETMGT: ICMP health probe failed for server 10.20.220.20:80 in serverfarm 'WEBFARM'
1d20h: %CSM_SLB-6-RSERVERSTATE: Module 5 server state changed: SLB-NETMGT: ICMP health probe failed for server 10.20.220.10:80 in serverfarm 'WEBFARM'
\Cat6k-2#
Cat6k-2# show module csm 5 probe detail
probe type port interval retries failed open receive
---------------------------------------------------------------------
PING icmp 2 2 10 2
real vserver serverfarm policy status
------------------------------------------------------------------------------
10.20.220.20:80 WEB WEBFARM (default) FAILED
10.20.220.10:80 WEB WEBFARM (default) FAILED
Cat6k-2#
Cat6k-2# show ip route
Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS inter area
* - candidate default, U - per-user static route, o - ODR
P - periodic downloaded static route
Gateway of last resort is 10.20.1.100 to network 0.0.0.0
10.0.0.0/8 is variably subnetted, 8 subnets, 3 masks
C 10.21.1.0/24 is directly connected, Vlan21
C 10.20.221.0/24 is directly connected, Vlan221
S* 0.0.0.0/0 [1/0] via 10.30.1.100
Configuring the Server Names
This example shows a different way to associate servers to server farms by using server names. This method is preferred when the same servers are associated to multiple server farms, because it allows the user to take a server out of rotation from all the server farms with only one command.
module ContentSwitchingModule 5
vlan 220 server
ip address 10.20.220.2 255.255.255.0
alias 10.20.220.1 255.255.255.0
!
vlan 221 client
ip address 10.20.221.5 255.255.255.0
gateway 10.20.221.1
alias 10.20.221.2 255.255.255.0
!
probe PING icmp
interval 2
retries 2
failed 10
receive 2
!
probe FTP ftp
interval 5
retries 2
failed 20
open 3
receive 3
!
probe HTTP http
request method head
expect status 200 299
interval 5
retries 2
failed 10
open 2
receive 2
!
real SERVER1
address 10.20.220.10
inservice
real SERVER2
address 10.20.220.20
inservice
!
serverfarm FTPFARM
nat server
no nat client
real name SERVER1
inservice
real name SERVER2
inservice
probe PING
probe FTP
!
serverfarm WEBFARM
nat server
no nat client
real name SERVER1
inservice
real name SERVER2
inservice
probe PING
probe HTTP
!
vserver FTP
virtual 10.20.221.100 tcp ftp service ftp
serverfarm FTPFARM
persistent rebalance
inservice
!
vserver WEB
virtual 10.20.221.100 tcp www
serverfarm WEBFARM
persistent rebalance
inservice
!
Output of some show commands:
Cat6k-2# show module csm 5 probe detail
probe type port interval retries failed open receive
---------------------------------------------------------------------
PING icmp 2 2 10 2
real vserver serverfarm policy status
------------------------------------------------------------------------------
10.20.220.20:21 FTP FTPFARM (default) OPERABLE
10.20.220.10:21 FTP FTPFARM (default) OPERABLE
10.20.220.20:80 WEB WEBFARM (default) OPERABLE
10.20.220.10:80 WEB WEBFARM (default) OPERABLE
FTP ftp 5 2 20 3 3
Expected Status Codes:
0 to 999
real vserver serverfarm policy status
------------------------------------------------------------------------------
10.20.220.20:21 FTP FTPFARM (default) OPERABLE
10.20.220.10:21 FTP FTPFARM (default) OPERABLE
HTTP http 5 2 10 2 2
Probe Request: HEAD /
Expected Status Codes:
200 to 299
real vserver serverfarm policy status
------------------------------------------------------------------------------
10.20.220.20:80 WEB WEBFARM (default) OPERABLE
10.20.220.10:80 WEB WEBFARM (default) OPERABLE
Cat6k-2# show module csm 5 real
real server farm weight state conns/hits
-------------------------------------------------------------------------
SERVER1 FTPFARM 8 OPERATIONAL 0
SERVER2 FTPFARM 8 OPERATIONAL 0
SERVER1 WEBFARM 8 OPERATIONAL 0
SERVER2 WEBFARM 8 OPERATIONAL 0
# Taking a server out of service at the server farm level will only take the server out of
# service for that specific farm
Cat6k-2# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Cat6k-2(config)# module csm 5
Cat6k-2(config-module-csm)# server webfarm
Cat6k-2(config-slb-sfarm)# real name server1
Cat6k-2(config-slb-real)# no inservice
Cat6k-2(config-slb-real)# end
1d20h: %CSM_SLB-6-RSERVERSTATE: Module 5 server state changed: SLB-NETMGT: Configured server 10.20.220.10:0 to OUT-OF-SERVICE in serverfarm 'WEBFARM'
Cat6k-2#
1d20h: %SYS-5-CONFIG_I: Configured from console by vty0 (10.20.1.100)
Cat6k-2#
Cat6k-2# show module csm 5 real
real server farm weight state conns/hits
-------------------------------------------------------------------------
SERVER1 FTPFARM 8 OPERATIONAL 0
SERVER2 FTPFARM 8 OPERATIONAL 0
SERVER1 WEBFARM 8 OUTOFSERVICE 0
SERVER2 WEBFARM 8 OPERATIONAL 0
Cat6k-2#
# Taking the server out of service at the real server level will take the server out of
# service for all the server farms
Cat6k-2# confure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Cat6k-2(config)# module csm 5
Cat6k-2(config-module-csm)# real server1
Cat6k(config-slb-module-real)# no inservice
Cat6k(config-slb-module-real)# end
Cat6k-2#
1d20h: %SYS-5-CONFIG_I: Configured from console by vty0 (10.20.1.100)
Cat6k-2# show module csm 5 real
real server farm weight state conns/hits
-------------------------------------------------------------------------
SERVER1 FTPFARM 8 OUTOFSERVICE 0
SERVER2 FTPFARM 8 OPERATIONAL 0
SERVER1 WEBFARM 8 OUTOFSERVICE 0
SERVER2 WEBFARM 8 OPERATIONAL 0
Cat6k-2#
Configuring a Backup Server Farm
This example shows you how to configure a backup server farm for a virtual server. If all the servers in the primary server farm fail, the CSM starts directing requests to the backup server farm. The sticky options allow you to control the backup operation if stickiness is configured for that virtual server.
module ContentSwitchingModule 5
vlan 220 server
ip address 10.20.220.2 255.255.255.0
alias 10.20.220.1 255.255.255.0
!
vlan 221 client
ip address 10.20.221.5 255.255.255.0
gateway 10.20.221.1
alias 10.20.221.2 255.255.255.0
!
vlan 210 server
ip address 10.20.210.2 255.255.255.0
alias 10.20.210.1 255.255.255.0
!
probe PING icmp
interval 2
retries 2
failed 10
receive 2
!
real SERVER1
address 10.20.220.10
inservice
real SERVER2
address 10.20.220.20
inservice
real SERVER3
address 10.20.210.30
inservice
real SERVER4
address 10.20.210.40
inservice
!
serverfarm WEBFARM
nat server
no nat client
real name SERVER1
inservice
real name SERVER2
inservice
probe PING
!
serverfarm WEBFARM2
nat server
no nat client
real name SERVER3
inservice
real name SERVER4
inservice
probe PING
!
vserver WEB
virtual 10.20.221.100 tcp www
serverfarm WEBFARM backup WEBFARM2
persistent rebalance
inservice
!
Output of some show commands:
Cat6k-2# show module csm 5 real
real server farm weight state conns/hits
-------------------------------------------------------------------------
SERVER1 WEBFARM 8 OPERATIONAL 0
SERVER2 WEBFARM 8 OPERATIONAL 0
SERVER3 WEBFARM2 8 OPERATIONAL 0
SERVER4 WEBFARM2 8 OPERATIONAL 0
# All the servers are shown as operational.
Cat6k-2# show module csm 5 serverfarm detail
WEBFARM, type = SLB, predictor = RoundRobin
nat = SERVER
virtuals inservice = 1, reals = 2, bind id = 0, fail action = none
inband health config: <none>
retcode map = <none>
Probes:
PING, type = icmp
Real servers:
SERVER1, weight = 8, OPERATIONAL, conns = 0
SERVER2, weight = 8, OPERATIONAL, conns = 0
Total connections = 0
WEBFARM2, type = SLB, predictor = RoundRobin
nat = SERVER
virtuals inservice = 1, reals = 2, bind id = 0, fail action = none
inband health config: <none>
retcode map = <none>
Probes:
PING, type = icmp
Real servers:
SERVER3, weight = 8, OPERATIONAL, conns = 0
SERVER4, weight = 8, OPERATIONAL, conns = 0
Total connections = 0
Cat6k-2# show module csm 5 vserver detail
WEB, type = SLB, state = OPERATIONAL, v_index = 18
virtual = 10.20.221.100/32:80 bidir, TCP, service = NONE, advertise = FALSE
idle = 3600, replicate csrp = none, vlan = ALL, pending = 30, layer 4
max parse len = 2000, persist rebalance = TRUE
ssl sticky offset = 0, length = 32
conns = 0, total conns = 0
Default policy:
server farm = WEBFARM, backup = WEBFARM2 (no sticky)
sticky: timer = 0, subnet = 0.0.0.0, group id = 0
Policy Tot matches Client pkts Server pkts
-----------------------------------------------------
(default) 0 0 0
# No connections have been sent to the virtual server yet.
Cat6k-2# show module csm 5 vserver detail
WEB, type = SLB, state = OPERATIONAL, v_index = 18
virtual = 10.20.221.100/32:80 bidir, TCP, service = NONE, advertise = FALSE
idle = 3600, replicate csrp = none, vlan = ALL, pending = 30, layer 4
max parse len = 2000, persist rebalance = TRUE
ssl sticky offset = 0, length = 32
conns = 0, total conns = 14
Default policy:
server farm = WEBFARM, backup = WEBFARM2 (no sticky)
sticky: timer = 0, subnet = 0.0.0.0, group id = 0
Policy Tot matches Client pkts Server pkts
-----------------------------------------------------
(default) 14 84 70
# A total of 14 connections have been sent to the virtual server and have been balanced to # the primary server farm. For each connection, the client has sent 6 packets and the # server has sent 5 packets. Two servers are taken out of service
Cat6k-2#
1d21h: %CSM_SLB-6-RSERVERSTATE: Module 5 server state changed: SLB-NETMGT: ICMP health probe failed for server 10.20.220.10:80 in serverfarm 'WEBFARM'
1d21h: %CSM_SLB-6-RSERVERSTATE: Module 5 server state changed: SLB-NETMGT: ICMP health probe failed for server 10.20.220.20:80 in serverfarm 'WEBFARM'
Cat6k-2# show module csm 5 serverfarm detail
WEBFARM, type = SLB, predictor = RoundRobin
nat = SERVER
virtuals inservice = 1, reals = 2, bind id = 0, fail action = none
inband health config: <none>
retcode map = <none>
Probes:
PING, type = icmp
Real servers:
SERVER1, weight = 8, PROBE_FAILED, conns = 0
SERVER2, weight = 8, PROBE_FAILED, conns = 0
Total connections = 0
# The two servers have failed the probe but the CSM has not yet refreshed the ARP table
# for them, so the servers are not yet shown in the failed state
WEBFARM2, type = SLB, predictor = RoundRobin
nat = SERVER
virtuals inservice = 1, reals = 2, bind id = 0, fail action = none
inband health config: <none>
retcode map = <none>
Probes:
PING, type = icmp
Real servers:
SERVER3, weight = 8, OPERATIONAL, conns = 0
SERVER4, weight = 8, OPERATIONAL, conns = 0
Total connections = 0
Cat6k-2# show module csm 5 vserver detail
WEB, type = SLB, state = OUTOFSERVICE, v_index = 18
virtual = 10.20.221.100/32:80 bidir, TCP, service = NONE, advertise = FALSE
idle = 3600, replicate csrp = none, vlan = ALL, pending = 30, layer 4
max parse len = 2000, persist rebalance = TRUE
ssl sticky offset = 0, length = 32
conns = 0, total conns = 14
Default policy:
server farm = WEBFARM, backup = WEBFARM2 (no sticky)
sticky: timer = 0, subnet = 0.0.0.0, group id = 0
Policy Tot matches Client pkts Server pkts
-----------------------------------------------------
(default) 14 83 70
# The virtual server is displayed as out of service, even if it is configured with a
# backup server farm, which is healthy. This behaviour is useful if the backup server farm
# is configured as an HTTP redirect server farm to a different site and you are using some
# DNS-based GSLB method, where some connections are still being directed to the failed
# virtual server.
# If you want the CSM to consider the virtual server healthy and operational if the backup
# server farm is healthy, you just need to change an environmental variable.
Cat6k-2# show module csm 5 variable
variable value
----------------------------------------------------------------
ARP_INTERVAL 300
ARP_LEARNED_INTERVAL 14400
ARP_GRATUITOUS_INTERVAL 15
ARP_RATE 10
ARP_RETRIES 3
ARP_LEARN_MODE 1
ARP_REPLY_FOR_NO_INSERVICE_VIP 0
ADVERTISE_RHI_FREQ 10
AGGREGATE_BACKUP_SF_STATE_TO_VS 0
DEST_UNREACHABLE_MASK 0xffff
FT_FLOW_REFRESH_INT 15
GSLB_LICENSE_KEY (no valid license)
HTTP_CASE_SENSITIVE_MATCHING 1
MAX_PARSE_LEN_MULTIPLIER 1
NAT_CLIENT_HASH_SOURCE_PORT 0
ROUTE_UNKNOWN_FLOW_PKTS 0
NO_RESET_UNIDIRECTIONAL_FLOWS 0
SYN_COOKIE_INTERVAL 3
SYN_COOKIE_THRESHOLD 5000
TCP_MSS_OPTION 1460
TCP_WND_SIZE_OPTION 8192
VSERVER_ICMP_ALWAYS_RESPOND false
XML_CONFIG_AUTH_TYPE Basic
# The variable that you want to change is AGGREGATE_BACKUP_SF_STATE_TO_VS
Cat6k-2#
1d21h: %CSM_SLB-6-RSERVERSTATE: Module 5 server state changed: SLB-NETMGT: Server 10.20.220.20 failed ARP request
Cat6k-2#
# The CSM has refreshed the ARP entry for 10.20.220.20 which is now reported in the failed
state.
Cat6k-2# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Cat6k-2(config)# module csm 5
Cat6k-2(config-module-csm)# variable AGGREGATE_BACKUP_SF_STATE_TO_VS 1
Cat6k-2(config-module-csm)# end
1d21h: %SYS-5-CONFIG_I: Configured from console by vty0 (10.20.1.100)
Cat6k-2# show module csm 5 variable
variable value
----------------------------------------------------------------
ARP_INTERVAL 300
ARP_LEARNED_INTERVAL 14400
ARP_GRATUITOUS_INTERVAL 15
ARP_RATE 10
ARP_RETRIES 3
ARP_LEARN_MODE 1
ARP_REPLY_FOR_NO_INSERVICE_VIP 0
ADVERTISE_RHI_FREQ 10
AGGREGATE_BACKUP_SF_STATE_TO_VS 1
DEST_UNREACHABLE_MASK 0xffff
FT_FLOW_REFRESH_INT 15
GSLB_LICENSE_KEY (no valid license)
HTTP_CASE_SENSITIVE_MATCHING 1
MAX_PARSE_LEN_MULTIPLIER 1
NAT_CLIENT_HASH_SOURCE_PORT 0
ROUTE_UNKNOWN_FLOW_PKTS 0
NO_RESET_UNIDIRECTIONAL_FLOWS 0
SYN_COOKIE_INTERVAL 3
SYN_COOKIE_THRESHOLD 5000
TCP_MSS_OPTION 1460
TCP_WND_SIZE_OPTION 8192
VSERVER_ICMP_ALWAYS_RESPOND false
XML_CONFIG_AUTH_TYPE Basic
Cat6k-2# show module csm 5 vserver detail
WEB, type = SLB, state = OPERATIONAL, v_index = 18
virtual = 10.20.221.100/32:80 bidir, TCP, service = NONE, advertise = FALSE
idle = 3600, replicate csrp = none, vlan = ALL, pending = 30, layer 4
max parse len = 2000, persist rebalance = TRUE
ssl sticky offset = 0, length = 32
conns = 0, total conns = 14
Default policy:
server farm = WEBFARM, backup = WEBFARM2 (no sticky)
sticky: timer = 0, subnet = 0.0.0.0, group id = 0
Policy Tot matches Client pkts Server pkts
-----------------------------------------------------
(default) 14 83 70
# The virtual server is now shown as operational.
Cat6k-2# show module csm 5 real detail
SERVER1, WEBFARM, state = PROBE_FAILED
address = 10.20.220.10, location = <NA>
conns = 0, maxconns = 4294967295, minconns = 0
weight = 8, weight(admin) = 8, metric = 0, remainder = 0
total conns established = 7, total conn failures = 0
SERVER2, WEBFARM, state = FAILED
address = 10.20.220.20, location = <NA>
conns = 0, maxconns = 4294967295, minconns = 0
weight = 8, weight(admin) = 8, metric = 0, remainder = 0
total conns established = 7, total conn failures = 0
SERVER3, WEBFARM2, state = OPERATIONAL
address = 10.20.210.30, location = <NA>
conns = 0, maxconns = 4294967295, minconns = 0
weight = 8, weight(admin) = 8, metric = 0, remainder = 0
total conns established = 0, total conn failures = 0
SERVER4, WEBFARM2, state = OPERATIONAL
address = 10.20.210.40, location = <NA>
conns = 0, maxconns = 4294967295, minconns = 0
weight = 8, weight(admin) = 8, metric = 0, remainder = 0
total conns established = 0, total conn failures = 0
Cat6k-2#
1d21h: %CSM_SLB-6-RSERVERSTATE: Module 5 server state changed: SLB-NETMGT: Server 10.20.220.10 failed ARP request
# The ARP entry for the other server has been refreshed.
Cat6k-2# show module csm 5 real detail
SERVER1, WEBFARM, state = FAILED
address = 10.20.220.10, location = <NA>
conns = 0, maxconns = 4294967295, minconns = 0
weight = 8, weight(admin) = 8, metric = 0, remainder = 0
total conns established = 7, total conn failures = 0
SERVER2, WEBFARM, state = FAILED
address = 10.20.220.20, location = <NA>
conns = 0, maxconns = 4294967295, minconns = 0
weight = 8, weight(admin) = 8, metric = 0, remainder = 0
total conns established = 7, total conn failures = 0
SERVER3, WEBFARM2, state = OPERATIONAL
address = 10.20.210.30, location = <NA>
conns = 0, maxconns = 4294967295, minconns = 0
weight = 8, weight(admin) = 8, metric = 0, remainder = 0
total conns established = 0, total conn failures = 0
SERVER4, WEBFARM2, state = OPERATIONAL
address = 10.20.210.40, location = <NA>
conns = 0, maxconns = 4294967295, minconns = 0
weight = 8, weight(admin) = 8, metric = 0, remainder = 0
total conns established = 0, total conn failures = 0
# So far, each of the servers in the primary server farm have received 7 connections. New
# connections are now sent only to the backup server farm.
Cat6k-2# show module csm 5 real detail
SERVER1, WEBFARM, state = FAILED
address = 10.20.220.10, location = <NA>
conns = 0, maxconns = 4294967295, minconns = 0
weight = 8, weight(admin) = 8, metric = 0, remainder = 0
total conns established = 7, total conn failures = 0
SERVER2, WEBFARM, state = FAILED
address = 10.20.220.20, location = <NA>
conns = 0, maxconns = 4294967295, minconns = 0
weight = 8, weight(admin) = 8, metric = 0, remainder = 0
total conns established = 7, total conn failures = 0
SERVER3, WEBFARM2, state = OPERATIONAL
address = 10.20.210.30, location = <NA>
conns = 0, maxconns = 4294967295, minconns = 0
weight = 8, weight(admin) = 8, metric = 0, remainder = 0
total conns established = 6, total conn failures = 0
SERVER4, WEBFARM2, state = OPERATIONAL
address = 10.20.210.40, location = <NA>
conns = 0, maxconns = 4294967295, minconns = 0
weight = 8, weight(admin) = 8, metric = 0, remainder = 0
total conns established = 6, total conn failures = 0
Cat6k-2#
Configuring Load-balancing Decisions Based on the Source IP Address
This example shows how to make a load-balancing decision based on the source IP address of the client. This configuration requires the use of slb-policies.
module ContentSwitchingModule 5
vlan 220 server
ip address 10.20.220.2 255.255.255.0
alias 10.20.220.1 255.255.255.0
!
vlan 221 client
ip address 10.20.221.5 255.255.255.0
gateway 10.20.221.1
alias 10.20.221.2 255.255.255.0
!
probe PING icmp
interval 2
retries 2
failed 10
receive 2
!
real SERVER1
address 10.20.220.10
inservice
real SERVER2
address 10.20.220.20
inservice
real SERVER3
address 10.20.220.30
inservice
real SERVER4
address 10.20.220.40
inservice
!
serverfarm WEBFARM
nat server
no nat client
real name SERVER1
inservice
real name SERVER2
inservice
probe PING
!
serverfarm WEBFARM2
nat server
no nat client
real name SERVER3
inservice
real name SERVER4
inservice
!
policy SOURCE-IP-50
client-group 50
serverfarm WEBFARM2
# A policy consists of a series of conditions, plus the actions to take if those
# conditions are matched. In this case, the only condition is client-group 50 which
# requires the incoming connection to match the standard access-list 50. The only action
# to take is to use server farm WEBFARM2 to serve those requests.
!
vserver WEB
virtual 10.20.221.100 tcp www
serverfarm WEBFARM
persistent rebalance
slb-policy SOURCE-IP-50
# Slb-policies associated to a virtual server are always examined in the order in which
# they are configured. The defintion of the server farm under the virtual server
# configuration is the default policy and is always used as a last resort if no policy
# matches, or if there are no policies configured.
# In this case, incoming requests are processed to see if they match the conditions of the
# slb-policy SOURCe-IP-50. If they do, then the server farm WEBFARM2 is used, otherwise
# the default policy is selected (for example, WEBFARM is used).
# If a default server farm is not configured, then connections that do not match any
# policy are dropped.
# This example shows how to configure the IOS standard access list. You can configure any
# of the 1-99 standard access lists, or you can configure named access lists
inservice
!
access-list 50 permit 10.20.1.100
Output of some show commands:
Cat6k-2# show module csm 5 vser detail
WEB, type = SLB, state = OPERATIONAL, v_index = 18
virtual = 10.20.221.100/32:80 bidir, TCP, service = NONE, advertise = FALSE
idle = 3600, replicate csrp = none, vlan = ALL, pending = 30, layer 4
max parse len = 2000, persist rebalance = TRUE
ssl sticky offset = 0, length = 32
conns = 0, total conns = 0
Default policy:
server farm = WEBFARM, backup = <not assigned>
sticky: timer = 0, subnet = 0.0.0.0, group id = 0
Policy Tot matches Client pkts Server pkts
-----------------------------------------------------
SOURCE-IP-50 0 0 0
(default) 0 0 0
# This example shows that six connections have matched the slb-policy SOURCE-IP-50.
Cat6k-2# show module csm 5 vser detail
WEB, type = SLB, state = OPERATIONAL, v_index = 18
virtual = 10.20.221.100/32:80 bidir, TCP, service = NONE, advertise = FALSE
idle = 3600, replicate csrp = none, vlan = ALL, pending = 30, layer 4
max parse len = 2000, persist rebalance = TRUE
ssl sticky offset = 0, length = 32
conns = 0, total conns = 6
Default policy:
server farm = WEBFARM, backup = <not assigned>
sticky: timer = 0, subnet = 0.0.0.0, group id = 0
Policy Tot matches Client pkts Server pkts
-----------------------------------------------------
SOURCE-IP-50 6 36 30
(default) 0 0 0
# This example shows that SERVER3 and SERVER4 have received 3 connections each.
Cat6k-2# show module csm 5 real detail
SERVER1, WEBFARM, state = OPERATIONAL
address = 10.20.220.10, location = <NA>
conns = 0, maxconns = 4294967295, minconns = 0
weight = 8, weight(admin) = 8, metric = 0, remainder = 0
total conns established = 0, total conn failures = 0
SERVER2, WEBFARM, state = OPERATIONAL
address = 10.20.220.20, location = <NA>
conns = 0, maxconns = 4294967295, minconns = 0
weight = 8, weight(admin) = 8, metric = 0, remainder = 0
total conns established = 0, total conn failures = 0
SERVER3, WEBFARM2, state = OPERATIONAL
address = 10.20.220.30, location = <NA>
conns = 0, maxconns = 4294967295, minconns = 0
weight = 8, weight(admin) = 8, metric = 0, remainder = 0
total conns established = 3, total conn failures = 0
SERVER4, WEBFARM2, state = OPERATIONAL
address = 10.20.220.40, location = <NA>
conns = 0, maxconns = 4294967295, minconns = 0
weight = 8, weight(admin) = 8, metric = 0, remainder = 0
total conns established = 3, total conn failures = 0
Cat6k-2#
Configuring Layer 7 Load Balancing
This example shows how to make load-balancing decisions based on Layer 7 information. In this case, the CSM terminates the TCP connection, buffers the request, and parses it to see if the request matches the policy conditions. When a load-balancing decision is made, the CSM opens the connection to the selected server and splices the two flows together.
The configuration in this example requires the use of maps and policies. A policy is a list of conditions and actions that are taken if all the conditions are true.
Cat6k-2(config-module-csm)# policy test
Cat6k-2(config-slb-policy)# ?
SLB policy config
client-group define policy client group
cookie-map define policy cookie map
default Set a command to its defaults
exit exit slb policy submode
header-map define policy header map
no Negate a command or set its defaults
reverse-sticky define sticky group for reverse traffic
serverfarm define policy serverfarm
set set policy parameters
sticky-group define policy sticky group
url-map define policy URL map
# The conditions are:
# -client-group (source IP matches a certain ACL)
# -cookie-map (match based on cookies)
# -header-map (match based on HTTP headers)
# -url-map (match based on URLs)
# The actions are:
# -serverfarm (the most common: use this serverfarm)
# -sticky-group (use sticky)
# -reverse-sticky (use reverse sticky)
# -set (set ip dscp)
\module ContentSwitchingModule 5
vlan 220 server
ip address 10.20.220.2 255.255.255.0
alias 10.20.220.1 255.255.255.0
!
vlan 221 client
ip address 10.20.221.5 255.255.255.0
gateway 10.20.221.1
alias 10.20.221.2 255.255.255.0
!
probe PING icmp
interval 2
retries 2
failed 10
receive 2
!
map TEST header
match protocol http header Host header-value www.test.com
!
map SPORTS url
match protocol http url /sports/*
# The definition of maps is based on the header and the URL. The URL starts right after
# the host. For example, in the URL http://www.test.com/sports/basketball/ the URL portion
# that the URL map applies to is /sports/basketball/.
!
real SERVER1
address 10.20.220.10
inservice
real SERVER2
address 10.20.220.20
inservice
real SERVER3
address 10.20.220.30
inservice
real SERVER4
address 10.20.220.40
inservice
!
serverfarm WEBFARM
nat server
no nat client
real name SERVER1
inservice
real name SERVER2
inservice
probe PING
!
serverfarm WEBFARM2
nat server
no nat client
real name SERVER3
inservice
real name SERVER4
inservice
!
policy TEST-SPORTS-50
url-map SPORTS
header-map TEST
client-group 50
serverfarm WEBFARM2
# Three conditions need to match for this policy to have a match.
!
vserver WEB
virtual 10.20.221.100 tcp www
serverfarm WEBFARM
persistent rebalance
slb-policy TEST-SPORTS-50
inservice
!
# If the three conditions defined in the policy are true then WEBFARM2 is used otherwise
# WEBFARM is.
Output of some show commands:
# In this example, 17 requests have matched the policy Of those, 12 requests have not
# matched the policy
Cat6k-2# show module csm 5 vserver detail
WEB, type = SLB, state = OPERATIONAL, v_index = 18
virtual = 10.20.221.100/32:80 bidir, TCP, service = NONE, advertise = FALSE
idle = 3600, replicate csrp = none, vlan = ALL, pending = 30, layer 4
max parse len = 2000, persist rebalance = TRUE
ssl sticky offset = 0, length = 32
conns = 0, total conns = 29
Default policy:
server farm = WEBFARM, backup = <not assigned>
sticky: timer = 0, subnet = 0.0.0.0, group id = 0
Policy Tot matches Client pkts Server pkts
-----------------------------------------------------
TEST-SPORTS-50 17 112 95
(default) 12 82 72
# This example shows that the 29 connections that were load balanced have been load
# balanced at Layer 7. For example, the CSM has to terminate TCP and parse Layer 5 through
# Layer 7 information.
Cat6k-2# show module csm 5 stats
Connections Created: 29
Connections Destroyed: 29
Connections Current: 0
Connections Timed-Out: 0
Connections Failed: 0
Server initiated Connections:
Created: 0, Current: 0, Failed: 0
L4 Load-Balanced Decisions: 0
L4 Rejected Connections: 0
L7 Load-Balanced Decisions: 29
L7 Rejected Connections:
Total: 0, Parser: 0,
Reached max parse len: 0, Cookie out of mem: 0,
Cfg version mismatch: 0, Bad SSL2 format: 0
L4/L7 Rejected Connections:
No policy: 0, No policy match 0,
No real: 0, ACL denied 0,
Server initiated: 0
Checksum Failures: IP: 0, TCP: 0
Redirect Connections: 0, Redirect Dropped: 0
FTP Connections: 0
MAC Frames:
Tx: Unicast: 359, Multicast: 0, Broadcast: 8,
Underflow Errors: 0
Rx: Unicast: 387, Multicast: 221, Broadcast: 1,
Overflow Errors: 0, CRC Errors: 0
Configuring HTTP Redirect
This example shows how you can configure the CSM to send HTTP redirect messages:
# This configuration represents the configuration of site A
module ContentSwitchingModule 6
vlan 211 client
ip address 10.20.211.2 255.255.255.0
gateway 10.20.211.1
!
vlan 210 server
ip address 10.20.210.1 255.255.255.0
!
map SPORTMAP url
match protocol http url /sports*
!
serverfarm REDIRECTFARM
nat server
no nat client
redirect-vserver WWW2
webhost relocation www2.test.com 301
inservice
!
serverfarm WWW1FARM
nat server
no nat client
real 10.20.210.10
inservice
real 10.20.210.20
inservice
!
policy SPORTPOLICY
url-map SPORTMAP
serverfarm REDIRECTFARM
!
vserver WWW1VIP
virtual 10.20.211.100 tcp www
serverfarm WWW1FARM
persistent rebalance
slb-policy SPORTPOLICY
inservice
# This configuration represents the configuration of site B
module ContentSwitchingModule 7
vlan 221 client
ip address 10.20.221.2 255.255.255.0
gateway 10.20.221.1
!
vlan 220 server
ip address 10.20.220.1 255.255.255.0
!
serverfarm WWW2FARM
nat server
no nat client
real 10.20.220.10
inservice
real 10.20.220.20
inservice
!
vserver WWW2VIP
virtual 10.20.221.100 tcp www
serverfarm WWW2FARM
persistent rebalance
inservice
Output of some show commands:
# To test the configuration, the first nine requests are sent to www1.test.com requesting
# the home page "/." The 10th request is sent to http://www1.test.com/sports/.
Cat6k-2# show module csm 6 vser deta
WWW1VIP, type = SLB, state = OPERATIONAL, v_index = 11
virtual = 10.20.211.100/32:80 bidir, TCP, service = NONE, advertise = FALSE
idle = 3600, replicate csrp = none, vlan = ALL, pending = 30
max parse len = 2000, persist rebalance = TRUE
ssl sticky offset = 0, length = 32
conns = 0, total conns = 10
Default policy:
server farm = WWW1FARM, backup = <not assigned>
sticky: timer = 0, subnet = 0.0.0.0, group id = 0
Policy Tot Conn Client pkts Server pkts
-----------------------------------------------------
SPORTPOLICY 1 3 1
(default) 9 45 45
Cat6k-2# show module csm 7 vser detail
WWW2VIP, type = SLB, state = OPERATIONAL, v_index = 26
virtual = 10.20.221.100/32:80 bidir, TCP, service = NONE, advertise = FALSE
idle = 3600, replicate csrp = none, vlan = ALL, pending = 30
max parse len = 2000, persist rebalance = TRUE
ssl sticky offset = 0, length = 32
conns = 0, total conns = 1
Default policy:
server farm = WWW2FARM, backup = <not assigned>
sticky: timer = 0, subnet = 0.0.0.0, group id = 0
Policy Tot Conn Client pkts Server pkts
-----------------------------------------------------
(default) 1 5 5
# Nine requests have matched the default policy for www1.test.com so they have been served
# by WWW1FARM. One request has matched the policy SPORTPOLICY and has been redirected to
# the second site that has then served the request.
# The following is an example of the request that was sent to www1.cisco.com asking for
# /sports/.
10.20.1.100.34589 > 10.20.211.100.80: P 1:287(286) ack 1 win 5840 (DF)
0x0000 4500 0146 763c 4000 4006 da85 0a14 0164 E..Fv<@.@......d
0x0010 0a14 d364 871d 0050 ec1d 69e6 7b57 aead ...d...P..i.{W..
0x0020 5018 16d0 96b2 0000 4745 5420 2f73 706f P.......GET./spo
0x0030 7274 732f 2048 5454 502f 312e 310d 0a43 rts/.HTTP/1.1..C
0x0040 6f6e 6e65 6374 696f 6e3a 204b 6565 702d onnection:.Keep-
0x0050 416c 6976 650d 0a55 7365 722d 4167 656e Alive..User-Agen
0x0060 743a 204d 6f7a 696c 6c61 2f35 2e30 2028 t:.Mozilla/5.0.(
0x0070 636f 6d70 6174 6962 6c65 3b20 4b6f 6e71 compatible;.Konq
0x0080 7565 726f 722f 322e 322d 3131 3b20 4c69 ueror/2.2-11;.Li
0x0090 6e75 7829 0d0a 4163 6365 7074 3a20 7465 nux)..Accept:.te
0x00a0 7874 2f2a 2c20 696d 6167 652f 6a70 6567 xt/*,.image/jpeg
0x00b0 2c20 696d 6167 652f 706e 672c 2069 6d61 ,.image/png,.ima
0x00c0 6765 2f2a 2c20 2a2f 2a0d 0a41 6363 6570 ge/*,.*/*..Accep
0x00d0 742d 456e 636f 6469 6e67 3a20 782d 677a t-Encoding:.x-gz
0x00e0 6970 2c20 677a 6970 2c20 6964 656e 7469 ip,.gzip,.identi
0x00f0 7479 0d0a 4163 6365 7074 2d43 6861 7273 ty..Accept-Chars
0x0100 6574 3a20 416e 792c 2075 7466 2d38 2c20 et:.Any,.utf-8,.
0x0110 2a0d 0a41 6363 6570 742d 4c61 6e67 7561 *..Accept-Langua
0x0120 6765 3a20 656e 5f55 532c 2065 6e0d 0a48 ge:.en_US,.en..H
0x0130 6f73 743a 2077 7777 312e 7465 7374 2e63 ost:.www1.test.c
0x0140 6f6d 0d0a 0d0a om....
# The following example is the message that the client has received back from
# www1.cisco.com. This message is the HTTP redirect message generated by the CSM
10.20.211.100.80 > 10.20.1.100.34589: FP 1:56(55) ack 287 win 2048 (DF)
0x0000 4500 005f 763c 4000 3e06 dd6c 0a14 d364 E.._v<@.>..l...d
0x0010 0a14 0164 0050 871d 7b57 aead ec1d 6b04 ...d.P..{W....k.
0x0020 5019 0800 8b1a 0000 4854 5450 2f31 2e30 P.......HTTP/1.0
0x0030 2033 3031 2046 6f75 6e64 200d 0a4c 6f63 .301.Found...Loc
0x0040 6174 696f 6e3a 2068 7474 703a 2f2f 7777 ation:.http://ww
0x0050 7732 2e74 6573 742e 636f 6d0d 0a0d 0a w2.test.com....
# The redirect location sent back to the client matches exactly the string configured with
# the webhost relocation www2.test.com 301 command because the client was browsing
# www1.test.com/sports/ and is redirected to www2.test.com/.
# In some cases this might not be the desired behaviour and there might be the need to
# preserve the original URL that the browser requested.
# To preseerve the URL that the browser requested, you can use the %p parameter as part of
# the redirect string.
# The configuration would then appear as:
# serverfarm REDIRECTFARM
# nat server
# no nat client
# redirect-vserver WWW2
# webhost relocation www2.test.com/%p
# inservice
# The following example shows the resulting redirect message which is sent back to the
# client:
10.20.211.100.80 > 10.20.1.100.34893: FP 1:64(63) ack 329 win 2048 (DF)
0x0000 4500 0067 7d95 4000 3e06 d60b 0a14 d364 E..g}.@.>......d
0x0010 0a14 0164 0050 884d 7093 b53b 4e0b e8a8 ...d.P.Mp..;N...
0x0020 5019 0800 2800 0000 4854 5450 2f31 2e30 P...(...HTTP/1.0
0x0030 2033 3032 2046 6f75 6e64 200d 0a4c 6f63 .302.Found...Loc
0x0040 6174 696f 6e3a 2068 7474 703a 2f2f 7777 ation:.http://ww
0x0050 7732 2e74 6573 742e 636f 6d2f 7370 6f72 w2.test.com/spor
0x0060 7473 2f0d 0a0d 0a ts/....
# In other cases, you may need to redirect an HTTP request to an HTTPS VIP, on the same or
# on a remote CSM. In that case, the URL request must change from http:// to https://
# You can do this by using the parameter ssl 443
# The configuration would then be as follows:
# serverfarm REDIRECTFARM
# nat server
# no nat client
# redirect-vserver WWW2
# webhost relocation www2.test.com/%p
# ssl 443
# inservice
# The following is the resulting redirect message sent back to the client.
10.20.211.100.80 > 10.20.1.100.34888: FP 1:65(64) ack 329 win 2048 (DF)
0x0000 4500 0068 2cda 4000 3e06 26c6 0a14 d364 E..h,.@.>.&....d
0x0010 0a14 0164 0050 8848 7088 b087 21e5 a627 ...d.P.Hp...!..'
0x0020 5019 0800 f39e 0000 4854 5450 2f31 2e30 P.......HTTP/1.0
0x0030 2033 3032 2046 6f75 6e64 200d 0a4c 6f63 .302.Found...Loc
0x0040 6174 696f 6e3a 2068 7474 7073 3a2f 2f77 ation:.https://w
0x0050 7777 322e 7465 7374 2e63 6f6d 2f73 706f ww2.test.com/spo
0x0060 7274 732f 0d0a 0d0a rts/....
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