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  • 1.  Spectrum and lldp/cdp

    Posted Nov 06, 2017 04:37 PM

    Hello all,

    There's something that I don't understand how Spectrum auto discovery is running, I have 2 cisco devices which are physically linked together by layer 2. Inside of Oneclick, I can't find that link but when I check CDP table under Oneclick Component details, I can see correctly that link.

     

    I have already activated all possible options in VNM (protocols, address table, ip source, traffic and so on) and in discovery console too, then I created again those two devices,run discovery connection but I have always a same result. I saw another detail that disturbed me : lldp table doesn't show a same result as cdp table. It means I found that link in cdp part and not in lldp part. Is it the cause of that link missing ? How can I force Spectrum to take into count the information of cdp and bypass lldp table ?

     

    I have Spectrum 10.1.1 under Linux.

     

    Thanks for your helps.

     

    Regards



  • 2.  Re: Spectrum and lldp/cdp

    Posted Nov 07, 2017 11:24 AM

    Hello, cisco CDP doens't necessaraly discover the phisical connection, but LLDP usualy does, and on link connections i think that the phisical connection is more usefull than Logical because on logical If one of the in between devices fall you migth have a false notion because the oper status of the ports can be up.



  • 3.  Re: Spectrum and lldp/cdp

    Broadcom Employee
    Posted Nov 08, 2017 04:38 AM

    Hello Phucsi

     

    Cisco CDP tables can selected to discover subnets, when using seed routers to define a larger discovery as follows:

    Populate the Seed Routers List

    You can populate the Seed Routers list to have Discovery determine the routed subnets from this list.

    Follow these steps:

    1. In the Seed Routers field, enter addresses or host names to build a list of one or more seed routers and click Add.
    2. From the Discovery Type drop-down list, choose one:
      • Routers only
        Discovers only the routing devices within the IP range or host name.
      • Routers and only local LANs in IP/Host Name Boundary List
        Discovers only the routed subnets within the IP range or host name.
      • Routers and all local LANs
        Discovers all subnets that are routed by the routers that are discovered in the IP range or host name.
    3. Depending on how you want CA Spectrum to discover subnets, choose one of the following options:
      • Select the 'Scan Subnets Using ICMP/SNMP Sweep’ option and then select the maximum subnet size that you want to discover.
      • Select the 'Discover Subnets Using:' option and then select either 'ARP tables,' 'Cisco CDP tables,' or both.
      • Continue setting configuration parameters in the other view sections, as needed.
      Seed Routers information has now been added to the Discovery configuration.

      Populate the Seed Routers List

      You can populate the Seed Routers list to have Discovery determine the routed subnets from this list.

      Follow these steps:

      1. In the Seed Routers field, enter addresses or host names to build a list of one or more seed routers and click Add.
      2. From the Discovery Type drop-down list, choose one:
        • Routers only
          Discovers only the routing devices within the IP range or host name.
        • Routers and only local LANs in IP/Host Name Boundary List
          Discovers only the routed subnets within the IP range or host name.
        • Routers and all local LANs
          Discovers all subnets that are routed by the routers that are discovered in the IP range or host name.
      3. Depending on how you want CA Spectrum to discover subnets, choose one of the following options:
        • Select the 'Scan Subnets Using ICMP/SNMP Sweep’ option and then select the maximum subnet size that you want to discover.
        • Select the 'Discover Subnets Using:' option and then select either 'ARP tables,' 'Cisco CDP tables,' or both.
        • Continue setting configuration parameters in the other view sections, as needed.
        Seed Routers information has now been added to the Discovery configuration.

    https://docops.ca.com/ca-spectrum/10-2-2/en/managing-network/modeling-and-managing-your-it-infrastructure/discovering-and-modeling-your-network/define-a-discovery-configuration#DefineaDiscoveryConfiguration-DiscoverConnectionsDuringScheduledDiscovery

     

     

     

    Also, have you tried enabling the "Traffic Resolution" protocol, in the discovery console?

     

    regards

    shane



  • 4.  Re: Spectrum and lldp/cdp

    Broadcom Employee
    Posted Nov 08, 2017 07:20 AM

    Unfortunately you can't disable just one of the Discovery Protocol Tables.

     

    How to Discover and Model the Network - CA Spectrum - 10.2 to 10.2.2 - CA Technologies Documentation 

    Discovery Protocol Tables  (enabled by default) - Determines whether Discovery uses the Discovery Protocol tables when mapping device connectivity. Supported discovery protocols include Cisco, Nortel, Cabletron Switch, Extreme, Alcatel, Foundry, and Link Layer.

     

    To further troubleshoot this, enable the "Debug AutoDiscovery" (to On) in the "AutoDiscovery Control" subview of VNM model. Then try to discover connections (select one of the model, right-click, select Reconfiguration --> Discover Connections). Once the discover connection action has finished, disable the AutoDiscovery debug mode.

    Review the $SSPECROOT/SS/ADiscDebug_yymmdd_hhmmss file.

     

    If you need further assistance, please open a case at CA Technical Support, attach the ADiscDebug_yymmdd_hhmmss file, $SPECROOT/Install-Tools/.history file, sapwalk2 output of the 2 Cisco devices (the sapwalk2 utility is located in $SPECROOT/bin/ directory) and the connection information (i.e.: Cisco1-Port_25 <--> Port_14-Cisco2).

     

    sapwalk2 syntax:

    sapwalk2.exe -i <IP_Address> -v v2c -s 1 -c <community> -o device_name.walk

     

    Thanks,

    Silvio