IOS SLB versus CSM

Hi,
trying to figure out a possible solution for a 6500 and got a bit confused. According to my knowledge, IOS SLB is working either in L2 (MAC) or L3/4 (NAT), to ensure load balancing. CSM comes in the game, but offers much more, extending to L4/7. Are the two solutions substitude or complementary? Is it true that only with an CSM can you get HTTP probes to check your load balanced server farm? What other differences do you know about these two solutions?
In the paper http://www.cisco.com/en/US/partner/products/hw/modules/ps2706/products_configuration_example09186a0080094066.shtml
it is stated that "To run Cisco IOS SLB software, you must configure the mode using the show ip slb mode [csm | rp] command before any configuration. In the show ip slb mode command, the rp argument is default. You can only configure csm argument if you have the Content Switching Module (CSM)."
While in
http://www.cisco.com/en/US/partner/products/hw/modules/ps2706/products_configuration_example09186a008009452d.shtml
cisco states that "You cannot run Cisco IOS® SLB software on the same switch as the CSM."
Any ideas on that?
Thanks in advance

there are 2 ways to configure the csm.
You can use the same ios slb command and just tell the switch that there is a csm with the command 'ip slb mode'.
Or you can use the 'module contentswitching ' command.
If you use the first method, you can't use both a CSM and ios slb on the same switch.
If you use the second method, it is ok to have both ios slb and csm.
IOS SLB offers L4-7 loadbalancing solution.
Just be aware that as soon as you do L7 or do some nating, you poor performance with ios slb compare to a CSM.
One advantage of ios slb is the capacity to do radius loadbalancing [inspecting radius packet to identify framed ip, ...]
This is why in CMX solution we combine both ios slb and csm.
IOS SLB is used to loadbalance radius and the CSM is used to loadbalance the rest of the traffic.
Personally, I would say if you just need some vpn or firewall loadbalancing, ios slb is enough.
If you need HTTP or any other traffic wthe CSM is a better choice.
Regards,
Gilles.

Similar Messages

  • Cisco IOS SLB or CSM?

    I am trying to inform myself if Cisco IOS supports Server Load Balancing (SLB) without the CSM. It appears this software has been integrated into a hardware module known as a Content Switching Module. (CSM)
    Aside from cost and being a hardware module (faster) in a IOS based Catalyst 6500, Is there a functional advantage / disadvantage of using the Cisco CSM over Cisco IOS Server Load Balancing or vice versa. Any comments would be appreciated. Thanks.
    Mark

    IOS SLB shares the same software code base as Cisco IOS and has all the software features sets of Cisco IOS software. IOS SLB is recommended for customers desiring complete integration of SLB technology into traditional Cisco switches and routers.
    The CSM is specifically designed to meet the demands of large Internet service providers (ISPs), Co-location facilities, Application service providers (ASPs), and Enterprise web server farms.
    These links might help you gain a better understanding:
    http://www.cisco.com/univercd/cc/td/doc/product/software/ios121/121newft/121limit/121e/121e8/iosslb8e.htm#xtocid32
    http://www.cisco.com/en/US/partner/products/hw/modules/ps2706/products_qanda_item09186a0080092384.shtml
    http://www.cisco.com/warp/customer/cc/pd/si/casi/ca6000/prodlit/ccsm_ds.htm

  • CSM - IOS SLB failover ?

    I can't see this from the documentation, but as far as I can see the configuration commands on the switch are the same for IOS SLB and for the CSM. Does this mean that if you have an CSM which fails, the subset of functions supported by IOS SLB will be ?
    I realise performance would be less and only 500 VIPs would be supported etc.
    Thanks
    Simon

    Simon,
    I do not think this is the case. If you look closely at the configuration you will see the command ip slb mode csm. This causes all SLB functions to be offloaded to the CSM. The default is ip slb mode rp which is IOS based. If the CSM fails then SLB will stop working. You will need to enter the command ip slb mode rp for it to work again.
    If you are running version 2.1 or above it is recommended you run ip slb mode rp and use the configuration command
    module ContentSwitchingModule X where X is the module number
    and the slb commands under this.
    Cheers
    Phil
    Cheers
    Phil

  • IOS SLB and probe failure

    Hello,
    we use server-load-balancing with IOS 12.1(19)E1
    We have a problem if the server receives more connections following error messages “REAL 192.168.197.8 (HSSAT1-LX) has changed to PROBE_FAILED” and few seconds later “REAL 192.168.197.8 (HSSAT1-LX) has changed to OPERATIONAL” appears and so on.
    We checked the server and they works proper.
    What could be the reason for probe failed?
    My configuration:
    ip slb probe HS-PROBE tcp
    interval 5
    ip slb serverfarm HSSAT1-LX
    nat server
    predictor leastconns
    failaction purge
    probe HS-PROBE
    real 192.168.197.8 99
    reassign 2
    inservice
    real 192.168.197.9 99
    reassign 2
    inservice
    ip slb vserver HS.SAT1.DE
    virtual xxx.xxx.xxx.xxx tcp www
    serverfarm HSSAT1-LX
    advertise active
    inservice standby allvips
    How does a TCP probe works? – I could not find more exact information in the documents to configure probes.
    Is it better to use another probe (icmp)? – or without any probe?
    When does it make sense to use probes?
    Best regards
    Stefan

    HI Stefan,
    tcp probes do a complete TCP 3-way handshake and normaly terminate the session. A problem which I had some times timeout for a session to be established might be to short if the server is "heavy" loaded.
    Probing on a specific method (TCP HTTP ...) is most of the times the better solution. Imagine a WEB-Server which is properly pingable but the httpd died due to some internal error. If you would probe on a per ping basis the loadbalancer will never notice this but if you monitor tcp-port 80 by a tcp probe or better a http probe you will notice this and the server would be taken out of the serverfarm. Even better but afaik not possible in IOS SLB is to probe a certain page e.g. index.html. As you know that the httpd is up and running and pages can be displayed.
    Regarding the probing issue it might be usefull to read the follwing link describing healthmonitoring with the CSM
    http://www.cisco.com/en/US/products/hw/switches/ps708/products_installation_and_configuration_guide_chapter09186a00801c5899.html#1024967
    Hope that helped.
    Best Regards,
    Joerg

  • IOS SLB and Stateless failover

    Trying to compare CSM and IOS SLB features. Read where the CSM can have "stateful" failover (maintains sessions) in a box-to-box scenerio. I also read where the IOS SLB can only provide "stateless" failover (I assume during failover, state/connection information is lost) using HSRP.
    Can anyone confirm what I have written?
    Your help is much appreciated.

    That is correct.
    The CSM can maintain state on connections on a failover using the "replicate csrp" command. This command is not available on IOS SLB.
    The following are links to the CSM commands and IOS SLB commands for your reference...
    CSM Config guide, release notes and commands:
    http://www.cisco.com/univercd/cc/td/doc/product/lan/cat6000/cfgnotes/csm_3_1/index.htm
    IOS SLB commands: http://www.cisco.com/en/US/customer/products/sw/iosswrel/ps1835/products_command_summary_chapter09186a008008805e.html
    IOS SLB config guide:
    http://www.cisco.com/en/US/customer/products/sw/iosswrel/ps1835/products_configuration_guide_chapter09186a00800ca75d.html
    hope that helps
    -Steve

  • IOS slb questions

    Hi,
    1. It is true that ip slb probe http is not working on 6509 without CSM card?
    2. Did someone had tested how many IOS SLB client connections can support a 6509 with SUP1A /MSFC2 without CSM card?
    Thanks,
    Yuti

    The Cisco CSM accommodates a wide range of common IP protocols?including TCP and User Datagram Protocol (UDP). Additionally, the Cisco CSM supports higher-level protocols, including HTTP, FTP, Telnet, Real Time Streaming Protocol (RTSP), Domain Name System (DNS), and Simple Mail Transfer Protocol (SMTP).
    The Cisco CSM allows full regular expression pattern matching for policies based on URLs, cookies, and HTTP header fields. The Cisco CSM supports any URL or cookie format?allowing it to load balance existing Web content without requiring URL or cookie format changes.

  • IOS SLB Loab Balance Questions

    Forgive me if this is the wrong forum but it was the closest one I found relating to my issue.
    I've trying to load balance four of our radius servers using IOS SLB. The config works well and the radius servers are accepting requests fine. I follow this article which wasn't too bad to follow:
    http://www.cisco.com/application/pdf/en/us/guest/netsol/ns377/c649/cdccont_0900aecd800eb95f.pdf
    My two questions are:
    1. Sticky Option
    I understand it's used to make sure the client's accounting information
    goes to the correct real server, but I'm not sure how it really works
    and what's the best time to set it to.
    Eg:
    ip slb vserver RAD-UDP-1646
    virtual 210.x.x.224 udp 1646
    serverfarm RADFARM
    sticky 86400 group 10
    inservice
    a/ The documentation says "This configuraion causes the sticky database to store its entries for 86,400 seconds of inactivity". What do they mean by "inactivity" - no radius packets coming through? inactivity from the user's end?
    b/ It also says "the client's IP address is added to the IOS SLB database..." - is this the client's framed IP that the ISP assigns to the customer???
    c/ And what would be the optimum time to set the sticky timer to be?
    2. SLB connection statistics
    core1-router#sh ip slb reals
    real farm name weight state conns
    203.x.x.74 RADFARM 8 OPERATIONAL 0
    203.x.x.78 RADFARM 8 OPERATIONAL 0
    203.x.x.79 RADFARM 8 OPERATIONAL 0
    203.x.x.80 RADFARM 8 OPERATIONAL 2
    When you disconnect, the slb stats still show you as being connected to
    the real server (and both udp ports) which isn't very accurate. There is a default "delay" time which handles TCP disconnections and after being disconnected for 10 sec, the SLB stats are updated to reflect this (I've verified this works)- but nothing about how it handles UDP disconnections??? This
    would skew the stats and give us a very bad misrepresentation of the
    number of current and valid connections. Is there anyway to correct this???
    Thanks.
    Andy

    Inactivity for IOS SLB means that after specified time of inactivity, the client will be free to be load balanced to another server. As long as they remain active without an idle time , they will remain connected to the same real server. For the client's IP address which is added to the IOS SLB database I think it is the frammed IP address which the ISP assigns. The optimum time for the sticky timer will be its default value or say 60 seconds.

  • IOS SLB and IBM Workload Manager

    Does anyone know if IOS SLB can function similar to Multinode Load Balancing (MNLB) in that the IOS router acts as a Services Manager which contacts the OS390 Worload Manager (WLM) who then reports back the best OS390 server for a particular connection.
    Under MNLB, the Local Director performs the task as the Services Manager, but can a IOS SLB router perform this task?
    Thank you for your help.

    Steve, thank you for the reply. I have a large-scale OS390 WLM request as I'm told that this is the method for providing server load-balancing in a sysplex environment. I wonder why it is not supported in version 4.X. Do you happen to know the long term goal for OS390 load balancing support?
    I appreciate your help, Thank you

  • IOS SLB RADIUS loadbalancing

    Hi Guys,
    can anyone confirm or point out errors in this config that I wish to pop on our 6509. We don't have a test environment, so I need to get as much feedback as I can on this.
    Thanks in advance,
    James
    no natpool WSB_RADIUS 10.176.57.115 10.176.57.115 netmask 255.255.255.128
    no serverfarm WSB_RADIUS
    no serverfarm WSB_RADIUS_NAT
    no policy WSB_RADIUS_NAT
    no vserver WSB_RADIUS
    no probe WSB_RADIUS_AUTH udp
    ip slb serverfarm WSB_RADIUS
    nat server
    real 10.176.57.38
    faildetect numconns 8 numclients 1
    inservice
    real 10.176.57.39
    faildetect numconns 8 numclients 1
    inservice
    real 10.176.57.40
    faildetect numconns 8 numclients 1
    inservice
    real 10.176.57.41
    faildetect numconns 8 numclients 1
    inservice
    ip slb vserver WSB_RADIUS
    virtual 10.176.57.115 udp 1813 service radius
    serverfarm WSB_RADIUS
    idle radius request 2
    inservice standby WSB
    interface Vlan130
    standby 130 name WSB

    IOS SLB provides RADIUS load-balancing capabilities for RADIUS servers. In addition, IOS SLB can load-balance devices that proxy the RADIUS Authorization and Accounting flows in both traditional and mobile wireless networks, if desired. IOS SLB does this by correlating data flows to the same proxy that processed the RADIUS for that subscriber flow.
    http://www.cisco.com/en/US/products/sw/iosswrel/ps1833/products_feature_guide09186a00802081ce.html#wp2889077

  • IOS SLB Exclusively for Internal Clients

    We would like to turn up IOS SLB in dispatched mode on (core) SUP720 MSFCs in an HSRP environment. We would sequester the farm(s) of IIS and Citrix servers on an 'SLB VLAN', with our internal client base on an 'Office VLAN'. All databases and other supporting servers for the SLB servers are also on the 'Office VLAN'.
    Question: are there any issues, caveats, or compromises related to the back-end SLB servers accessing required resources on the Office VLAN? I am thinking that normal database and supporting traffic initiated by the SLB servers would just traverse the MSFC (as the default gateway) via inter-VLAN routing and that only the client-initiated, VIP-destined traffic on the Office VLAN would be handled by the IOS SLB feature and policies. In this thinking, supporting traffic replies from the databases back to the SLB server would use the routed SLB server's real IP address.
    Thanks in advance for any input and experiences with this topology. I'm hoping that this is a forest-for-the-trees situation, but I haven't seen many references to an all-internal deployment of either IOS SLB or appliance-based SLBs.
    Thanks,
    Gene

    If you are using dispatched mode, it needs to be L2 adjacent.In dispatched mode, the virtual server address is known to the real servers and IOS SLB redirects packets to the real servers at the media access control (MAC) layer.Phase I of IOS SLB implements dispatch mode only for packet redirection.In this mode, the real servers must be Layer 2 adjacent to the device redirecting packets,not beyond an additional router.

  • IOS SLB dns probe

    Hi,
    I'm trying to configure a DNS probe using IOS SLB, but it's not working.
    I followed the manual on how to configure a DNS probe, but it just doesn't make any sense.
    When using DNS probes on an ACE, you give a hostname which the DNS server should resolve to a configured IP Address.and configure an ip address, which makes sense.
    On the IOS SLB, it is not the case. Two variables can be configured:
    Router(config-slb-probe)# address ip-address]
    (Optional) Configures an IP address to which to send the Domain Name System (DNS) probe.
    Router(config-slb-probe)# lookup [ip-address]
    (Optional) Configures an IP address of a real server that a Domain Name System (DNS) server should supply in response to a domain name resolve request.
    What am I missing. Could someone please clearify??
    Tnx!

    To verify that a probe is configured correctly, use the show ip slb probe command:
    Router# show ip slb probe
    It may help you in troubleshooting purpose
    For the further description for configuration for the DNS Probe following guide may help you
    http://www.cisco.com/en/US/docs/ios/12_2/12_2z/12_2za/feature/guide/slbza5.html#wp2434837

  • Cisco IOS SLB

    Hello Guys,
    I am wondering if cisco 3750 Series support Cisco IOS SLB for SMTP protocol,  Can anyone help me in this?
    Thanks in advance,
    Jagdev

    Hi Jagdev,
    Cisco supports IOS SLB only on Cat 6k, 7x00
    Siva

  • Cat 6500 SupEng MSFC II IOS SLB performance

    Hello,
    anyone know which are the current cat 6500 Supervisor Engine II MSFC II IOS SLB performance ? I need to know the max tcp/udp cuncurrent active session and the max tcp/udp setup rate.
    Thanks a lot.
    Best regards
    Fabio Bellini

    check out the following link for the performance details :
    http://www.cisco.com/en/US/products/hw/modules/ps2706/products_data_sheet09186a00800887f3.html

  • IOS SLB and FWSM

    Hi, this may be a silly question but is there any problem with configuring IOS SLB on a 6509 which also has a FWSM module in it and the Servers being load balanced are behind the FWSM?

    The only thing to consider is that by FWSM, you most likely will be running multiple VRFs on the switch and IOS-SLB has some limitations regarding VRF.
    IOS-SLB probes are sent to the global routing table (VRF default) and you will need to 'no advertise' and add static routes to null0 to the VRF for the virtual IPs.
    Other than that, IOS-SLB works fine with the FWSM and VRF...

  • IOS SLB inservice standby

    Hi,
    I would like to know what is the main purpose of use the "standby" at the "inservice standby <group>" defined under the virtual server?. It's just a information ("as description") to associate the HSRP standby into this virtual server or it's have another function?.
    Thanks,
    Marcelo

    Marcelo,
    IOS SLB "inservice standby" is used where you require stateless redundancy for vservers across 2 SLB routers or switches. Using this command makes the vserver state follow the HSRP state of the relevant interface, to prevent the situation where one router is processing routing traffic but the other router is active and listening for traffic directed to the vserver address. It is much more than a description for the HSRP group, it is the mechanism to allow redundancy to function.
    This page has details0
    http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122cgcr/fipr_c/ipcprt1/1cfsflb.htm#1001434
    Regards, Peter

Maybe you are looking for

  • Follow Up to iMac G5 Crash n Burn

    If you go here you will read of an issue my wife was having. We thought it was resolved and this is a follow up to that/those issues. In the end it was a defective hard drive. Which Apple replaced after confirming what Diskwarrior® had identified aft

  • Updateable View ORA-2014

    Okay you helped me with the insert on a view with this note although you never completely answered all my questions: http://technet.oracle.com:89/ubb/Forum2/HTML/005469.html Now I need help with an update on a view. I have an instead of update trigge

  • I cannot access the email I used when I originally...

    Hi there  I feel like I'm in the seventh circle of Hell! I have had Skype for a long time and used an old work email address to set up my account. I now have a new lap top and am setting up Skype. I have forgotten my password. The forgotten password

  • Regarding workflor archiving

    Hi all, we are in process starting workflow archiving and the scenario as below adding a dedicated application server to the existing setup due to huge data and planning to run archiving jobs in the particular server only. ran couple of Test jobs, in

  • Export single table from Production

    Dear Experts I have to export a single table from Production and import that into Quality. In SCC8 we have a option in expert mode (SingleCopy option tables) will this help me in exporting the data of a single table if yes but which profile do we sel