This is the blog of Ronald Bartels that wanders on and off the subject of problem management (that is how it started). Mostly now the topics are about IoT and SD-WAN.
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Denying your spanning tree
As I suspected, the customer had disabled spanning tree due to
concerns about the speed of failover. They had also managed to patch a
layer 2 loop into their network during a minor change, causing an
unchecked loop to circulate frames out of control, bringing down their
entire cell site. I explained to them the value of STP, and why any outage caused by it
would be better than the out of control loop they had. I was told to
mind my own business. They didn’t want to enable spanning tree because
it was slow. Yes, I said, but only when there is a loop! And in that
case, a short outage is better than a meltdown. Then I realized the customer and I were in a loop, which I could break by closing the case. Newer technologies (such as SD-Access) obviate the need for STP, but if you’re doing classic Layer 2, please, use it.
Firewalls are becoming increasingly important in today’s world. Hackers and automated scripts are constantly trying to invade your system and use it for Bitcoin mining, botnets or other things. To prevent these attacks, you can use a firewall on your system. IPTables is the strongest firewall in Linux because it can filter packets in the kernel before they reach the application. Using IPTables is not very easy for Linux beginners. We have created easywall - the simple IPTables web interface . The focus of the software is on easy installation and use. Access this neat software over on github: easywall
When building a DDoS mitigation service it’s incredibly tempting to think that the solution is scrubbing centers or scrubbing servers. I, too, thought that was a good idea in the beginning, but experience has shown that there are serious pitfalls to this approach. Read the post of at Cloudflare's blog: N o Scrubs: The Architecture That Made Unmetered Mitigation Possible
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