[AusNOG] Work experience in networking/telecoms/DCs? Getting my foot in the door?

Chris Bennett chris at ceegeebee.com
Wed Dec 24 11:17:22 EST 2014


> You just gave me shudders with the memories of that one Andy, I've
> seen that happen on a very big network, 

This kind of war story (I've done it too) is one of the simplest
examples of where policy-based deployment / SDN can be harnessed.

>From the puppet/chef/ansible world, you would express the addition of
a vlan in plainer english terms, and your orchestration system goes
off and does it (without any of the risk of omitting the word 'add' :)
).

> my favorite though is adding VLAN's to an ether channel port
> directly and not to the port-channel directly 'sigh'.

Yup, I've seen a customer work interface by interface slowly killing
the redundancy in a port-channel as they amend the vlan list on the
physicals.

However there are still some older switches (3750's in my experience)
with certain code releases where you amend the vlan list on the
port-channel, it applies to the running config of both port-channel &
physical, but then in startup-config, only commits the vlan to the
port-channel.  It's left as an exercise to the reader as to what
happens on next-boot for the port-channel on that switch :)

This where the programmer part of a network engineer is needed - I
wrote an explicit test in my monitoring system that detects a vlan
mismatch between the running & saved version of a config so myself &
colleagues never get caught by this kind of problem again :)

Regards,

Chris


More information about the AusNOG mailing list