BLT first connection

Now that you have put everything at work by following instructions in "INSTALL" files provided with the distribution you are left with a nice blank screen...

From now on, you first need to set up your BGP session with a BGP LS aware device.
You can have a look at this document to gain a better idea of current implementations. Here below the configuration that you will need on a Cisco IOS XR router (from 5.1.2 onwards) :

Note that Cisco IOS XRv virtual router demo version could be very convenient for this purpose...

!! BGP config :
router bgp 1
 !! BGP LS AF activation
 address-family link-state link-state
  remote-as 1
  !! BLT do not accept incoming connections, 
  !! so passive mode guarantees that BLT will not receive any TCP SYN
  session-open-mode passive-only
  address-family link-state link-state
!! IGP config : here below OSPF and ISIS DB are both injected into BGP
router isis 1
 distribute bgp-ls
router ospf 1
 distribute bgp-ls

Now back to BLT, you can configure your BGP session parameters :

  • click on "Administration"
  • then "Networks", "Add network"
  • provide peer ASN (yes you can do eBGP or iBGP), peer IP address
  • click on "Add community"
  • add an IP subnet containing IP addresses of all the nodes you want to monitor, along with a SNMP community stringi. These are most commonly Loopback adresses reserved for inband management, you don't need to provide SNMP connectivity to each and every router-id.

If you have a look at the logfile, you'll see BGP session establishment, and SNMP polling tasks triggered when BGP LS updates are correctly handled by BLT

Upon refresh, your network devices should appear on the map. You can now rearrange nodes and links by clicking on the blue pen icon (top left of the window) Save your work by clicking on the floppy icon.

You can also check that all data is saved inside blt-data.xml file, located in your rundir, especially x-y coordinates of the devices.

Disconnect from BLT : "user admin", "disconnect"
and connect again to check that everything has been saved and restored properly.

Tags : blthowto