Nmap vs. OpenNMS Meridian

If you're a sysadmin, or anyone who's had to deploy network services, you've almost certainly had to use Nmap at some point or other. Need to see what devices are on your LAN? Nmap can tell you that. Want to check which ports your web server has open to the internet? Nmap is your friend.

Nmap is a powerful command-line tool and has many options that require some reading of documentation to get the best out of (although generally straightforward). If the thought of working at the command-line scares you (presumably not if you're reading this review), then you may want a much simpler tool, or at least check out Zenmap GUI.

Incentivized

I would recommend all system administrators use some form of network monitoring if they are not already doing so, and I'd definitely recommend people consider OpenNMS if they're shopping around. Small businesses will benefit from the low-cost of entry (it's free!), whilst getting all the enterprise features. Larger businesses can benefit from paid support plans.

However, there's no getting around the fact that you will require some advanced networking and sysadmin knowledge to get the most out of OpenNMS, or at least, be prepared for a steep learning curve. If you don't have the resources to devote this time initially, you may struggle.

Incentivized

• NMap provides a very fast and a very thorough network "sweep" that allows you to quickly map out exactly what's on your network.
• NMap is highly configurable. The "canned" choices are very good in most instances, but using various switches and options, you can create a very specific scan and get exactly the results you're looking for.
• NMap is easy to use. Even a new administrator will be able to use the graphical version (Zenmap) with efficiency right away.

Incentivized

• Report on SLA
• Group network areas
• Discovery of elements

Incentivized

• exporting, There's a serious lack of ability to export the information in a readable format to present to VPs and such. I always find myself doing a lot of data massaging to get it in a pretty format
• some scans can trigger sensitive IDS/IPS
• SYN scans can be particularly aggressive and cause problems on remote systems.

Incentivized

• We've had a few issues with delayed alerting.
• I haven't quite figured out how to make topologies work yet, but I haven't spent a ton of time on it either.
• We've also had a bit of trouble importing some MIBs, but that usually boiled down to working with the vendor to make sure we had the right MIBs and dependencies.

Incentivized

There is a very large support community and a robust selection of add-ons and scripts. Once you get the use down this is one of the most powerful tools and you can find anything you are looking for as far as examples on the web. While not having official support its not lacking by any means.

Incentivized

Alternatives to Nmap (other IP scanners) are often much more limited in what they can do; They often only allow you to scan a specific subset of ports or a limited number of IP addresses in one command. Nmap is unrestricted in that regard. What makes Nmap stand out above the rest, is the complete network analysis package you get with it. It allows IP scanner, network deep-dives, hardware analysis, vulnerability analysis, encryption detailing, and so much more, in one free application

Incentivized

OpenNMS's more attractive GUI and its price break were the main reasons our company chose to explore and use this product. However, it never managed to actually replace Nagios which had a much more established hold within the company. Perhaps we were over-monitoring, but our company claimed a $100k loss per hour of downtime.

Incentivized

• Nmap with Wireshark is free, so it's been a great combo team to gather info and test.
• It's allowed us to avoid fines from false positives and to fix actual issues ourselves.
• Great for finding hosts, helps keep the network secure.

Incentivized

• Initial adoption required quite a lot of resources and time to get everything right. Totally worth it for us; just be prepared for a gradual process that will get better and better with time.
• Once setup and running smoothly, it provides us with all the reporting we could hope for, at near zero cost.
• With OpenNMS, we're able to offer a much more reliable service to our customers, and spend a lot less time dealing with issues.

Incentivized