After writing the first article I was left with couple bits that I wanted to mention but they didn’t quite fit. So I have decided to write up a follow up where I would like to outline what I think would be the ideal process and some other notes on questions commonly asked.
How (not) to interview – part I
This Article will be bit unusual for this blog as it is not about any technology but it is about my experience with interview process. I had the opportunity of experiencing it from both sides many times and quite intensively during the last year or so. And I made quite a few observations that I think are worth sharing.
source system services from a routing instance
Let me start with couple of statements that would explain the issue in broader terms. JUNOS is system based on fairly old version of FreeBSD UNIX (I think something like version 4.X). The BSD serves as the underlying layer for services that run like daemons on top of the OS. This is great for many reasons as you can do thing like separate various functions completely in daemons. Or you can use some existing BSD packages without much work allowing for faster implementation of needed features. Also BSD in general is quite good for for the way it treats the kernel/network stack (which is different from Linux). So how does this look like? In the traditional JUNOS the logic would be something like this:
SLA probe IP-monitoring default route withdrawal
When an SRX is your wan facing router/firewall you might want to continuously test your connectivity. That is when the RPM probes do come in handy. The RPM probes are very similar to ip-sla from cisco but way more limited. On their own they just provide statistics which is nice but not very helpful. Juniper also has a feature called ip-monitoring that works in conjunction with the rpm probes and can take a result of an rpm probe and take some action on it.
ex3300 – removing virtual chassis (autobonding)
The ex3300 has a feature out of the box which is that specific ports are by default used for virtual chassis function. This might be handy in some situations but most of the time it is annoying and bit obscure. This short article will explain how to disable this feature completely and permanently.