Tag Archives: nms

Use python to talk to NNMi

One more post for people who work with NNMi 9.x. NNMi, being a jboss animal, has a pretty decent WS-I API to talk to the world. The interface is documented in the developer’s toolkit guide (available from the HP documentation site, need an HP passport account to access) and open.

Accessing the API is peanuts to any Java developer, but for the rest of us, it’s not straightforward. Well, with a little help from Python, everything is possible:

#!/usr/bin/python

from suds.client import Client
from suds.transport.http import HttpAuthenticated

t = HttpAuthenticated(username='system', password='NNMPASSWORD')

url = 'http://nnmi/NodeBeanService/NodeBean?wsdl'

client = Client(url, transport=t)

# Retrieve full node list
allNodes = client.service.getNodes('*')

print "Nodes in topology:", len(allNodes.item)

for i in allNodes.item[:]:
  print i.name,i.deviceModel

This small script connects to the NNMi NodeBean web service, retrieves the full list of managed nodes to populate the ‘allNodes’ object and from there it prints out the hostname and device type as discovered from NNMi. What you need is the suds library (available here, or installable with a few clicks in the Ubuntu software center).

Tech dive: Custom incidents in HP NNMi 9.10

This post is a tech dive into HP NNMi 9.10, intended to illustrate a way to create custom incidents. People that make a living from tuning and playing with NNM should find it rather interesting, others are encouraged to seek amusement elsewhere….

NNMi 9.10 is a substantial progress from NNM editions before 8.xx. It is an entirely new implementation, based on JBoss and designed as NNM should have been all along: Multithread, multiuser, with a decent database and an open (web services) API. Being new, certain things are done in a different way, and one of them is generating custom incidents.

Recently I was asked to implement in NNMi 9.10 a way to create an event and change the status of a network node whenever a certain condition occured. The nodes in question were branch office routers with ISDN interfaces as backup lines and the condition was the activation of the ISDN interface. The customer wants their NOC to be alerted whenever a branch office router activates the ISDN interface when the primary line goes down. The catch here is that a switch to the ISDN backup line is not regarded as an event from the NNMi perspective, since whenever the router detects that the primary route goes down, it turns it administratively down and brings up the ISDN interface, so there is no fault: The router is polled normally from the ISDN side from NNMi and no incident is created, the node remains green.

In previous versions of NNM, it was possible to change the internal OvIfUp event of NNM so that it triggered an external action, a perl script that manually changed the node status and created an NNM event. With NNMi 9.10, this is no longer the case. So, what do we do now?

The first step is to go to the configuration menu -> Custom poller configuration and create a custom poller collection, as above. Enable the custom poller and create a new one, with the name “ISDN Poller”.

Above is the poller creation form. The important stuff is the MIB expression and the MIB Filter variable. What we want is to check the operational status of the ISDN interface: The algorithm that the poller should do is to poll the interfaces of the router, filter out the ISDN interface via the “ifDescr” MIB variable and then check the value of the operational status of that interface. If this is “Up” the router should be set in the “Major” state. This is shown in the form above: The MIB filter is set to ifDescr and we select to poll the ifOperStatus object from the “MIB Expression” field: We create a new expression, select “ifOperStatus” from the MIB mgmt-2 interfaces tree and set the node status to “Major”.

The next step is to make this poller work for us, so we need to bind it to a policy, as shown below. Go to the “Policies” tab and create a new policy. Select the node group that you want the new custom poller to be applied to and type the MIB filter. The MIB filter will be matched to the “MIB Filter Variable” of the previous form, in our case, this is “Dialer1”, which is set to the router as the ISDN interface.

That’s it. After this configuration, the custom poller will be activated according to the defined policy: It will run only for the node group (Collection) you have specified, will poll only the interfaces that their description is “Dialer1”, which in our case are ISDN interfaces, and whenever the Operational Status (ifOperStatus) of these interfaces is set to “1”, which is “Up”, a new incident will be created and the node will turn orange on the map (Major status). Straightforward? No. Does it work? Yes.

Your Virtual Cisco IOS

Want to play with IOS but you don’t have a catalyst around? Try this. GNS3 is a marvelous and clever frontend to dynamips, dynagen and qemu which allow emulation/execution of IOS and JunOS code under a third operating system. That is, Cisco and Juniper virtualized on your desktop.

GNS3 topology of our virtual lab

What you will need is a decent PC with lots of memory (4GB to start with plus a fast CPU) and IOS/JunOS software images. The first is easy to do, for the second you will need access to licensed software or the actual hardware itself. My recommendation for the OS is Ubuntu with readily donwloadable and installable packages of all bits and pieces (# apt-get install gns3), however windows works just fine but with the 4GB constrains for a 32bit OS. Cool screenshots here.

How it works in a few words: MIPS and PPC based hardware (Cisco 26xx, 36XX, 37xx, 72xx) is emulated via dynamips running the IOS image unchanges. JunOS on the other hand is emulated with qemu using Olive, a stripped down version of JunOS, sort of an SDK. You design the topology via a snappy GUI (that is, GNS3), configure your virtual gear and then GNS3 fires up the emulators underneath. CPU and mem usage go skyhigh, but then, you have your own virtual private lab. Communication with the real world (the wire) is done via tap and bridge interfaces. Using a sniffer you can actually see real packets (with Cisco MAC prefixes and stuff) from your virtual devices swimming in your LAN.

What will work: All popular Cisco IOS devices with most linecards, JunOS Olive.

What will not work: Virtualizing dynamips itself is tricky. The emulator engine will work in a virtual host savagely consuming virtual CPU and memory resources, yet, the forged MAC addresses may not exit your hypervisor virtual switch. In vSphere, *sometimes* dynamips could emit packages only to other virtual machines running on the same ESX host, but this was not always the case… Also, note that performance is sluggish, so use GNS3 only as a demonstration and lab tool.

The car paradigm

Have you ever come across a situation where you have to explain something in 3 minutes to an audience which seems to have no clue what you are talking about? Use the car metaphor. It works.

Cars are ubiquitous. We all use them, either driving them or being simple passengers. We know their shape, size, their brands, the engine noise – some even¬†name¬†their cars. They are big or small, fast, slow, mean, cute. Making a parallelism of a solution or product with cars is easier, but you have to pick the right attributes. An example is systems and network management and why you need them. Try to drive your car without adjusted mirrors and no dashboard: You don’t know if there are other cars in your rear corners, so you cannot change lane easily or turn. You don’t know how fast you are going, neither if your engine runs too hot. You don’t know how much gas you have in your tank. Pretty awkward, right? Well, it’s the same with running an IT and network ¬†infrastructure without some kind of OSS or network management framework: As long as you drive straight and with a constant speed, everything is fine, yet, at some time, something will break down, a service will start spinning, storage pools will degrade or fill up, Will you be aware of these events before they occur and phones start ringing?