I was asked from developers to tell about git how we use it in operations team (aka SRE/DevOps). In an ideal world, developers should teach operation guys how to use git at scale. But sometimes reality is far away.
Route leaks or even hijacks are one of the biggest flaws in global routing.
Using DNS-based load balancing doesn’t save you from the failure. DNS server doesn’t know if the backend is up or down. It just responds without carrying about the state of the backend.
In my previous lighting blog post, I described how it’s possible to null route the whole datacenter by having fat-finger syndrome.
If you use Clos topology you should be aware that there are no direct links between leaves or spines. So, if you announce the default route unconditionally, you know what happens - traffic destined to
::/0) is blackholed. And what happens if you want to announce the default route conditionally? Let’s say I need to announce
only if an arbitrary community
123:1 exists. For instance:
As usual, the latest update broke OSX again. In most cases there are few options to fix this piece of crap:
We had an issue where the whole IPv6 block /32 was blackholed due to fat-fingers syndrome. The mask for the prefix was accidentally missed and IPv6 traffic just went off.