Keegan, don't get me wrong, I am not suggesting that even if version numbers were happily encoded in robust comments that this would be the same as actually digesting the configuration. If the function of checking using 'fancy versioning' is not an operational best practice, what do you suggest (all-knowing/singing/dancing tool which understands the configuration and your intent aside)? You say IF NTP or CPP were configured differently - with a large enough network there will always be configurations which have differences. With that as an operational constant, how do you determine which devices have the latest iteration of your line vty configuration. How often will a change not be rolled out to every router. This is again related to the size and churn of the network, but my practical estimation is that once you get into thousands of routers there will almost always be some that get missed. Comprehensive auditing is very important, and arguably more useful than version checking - but it requires that you make knowledgeable and complete assertions. I assert the my snmp config should look like the snmp snippet version 77 is easier to grok than "make sure our community string is not set to public" (and repeat hand-crafted audit logic for every segment of the config). What if some of the configs don't match the defined versions? This is why it may make sense to break snippets into functional areas. "Just fix it" might be sane for a banner, but squashing an interface mtu change that was put there for a reason could end in tears. I consider this bit out of the scope of the question, but yes it is another important problem. On Thu, Feb 27, 2014 at 10:03 PM, Christopher Morrow < morrowc.lists@gmail.com> wrote:
Putting aside the fact that snippets aren't a good way to conceptualize deployed router code, my gut still tells me to question the question here. The first is does this stuff change often enough to warrant a fancy versioning solution? I have yet to see NTP deployed in a different way
On Thu, Feb 27, 2014 at 8:38 PM, Keegan Holley <no.spam@comcast.net> wrote: than when I first learned to configure it. Next, when it does change how often is it not rolled out to every router. If NTP or CPP or SNMP or some other administrative option were configured differently across my
sure, so you're saying that a large bit (maybe) of the router config is 'one size fits all' and 'never changes' where 'never' is really 'very infrequently'.
sure, agreed... but there are parts of the config that do change more frequently (depending on the network perhaps)... how do you go about seeing which version / setup is deployed EXCEPT by building a home-grown 'config parser' and seeing that 'what is deployed matches mostly what I have in my config store for this router/class-of-router/network' ?
It's a shame that vendors of network equipment don't have to manage large networks of their own equipment under constrained opex environments (no fair comparing contracted work where you bill for time + materials, that's the wrong incentive set)... I bet that'd get them to fix stuff up right quick.
network I would want to audit it and fix not version control. What if some of the configs don't match the defined versions? It may be better to create standard templates and version them in SVN or GIT and then use config backups to track which devices have the standard configs. There are some for pay tools that can search for certain statements on various boxes and either alert or remediate when differences are found.
On Feb 26, 2014, at 4:22 PM, Ryan Shea <ryanshea@google.com> wrote:
Howdy network operator cognoscenti,
I'd love to hear your creative and workable solutions for a way to track in-line the configuration revisions you have on your cisco-like devices. Let me clearify/frame:
You have a set of tested/approved configurations for your routers which
IOS style configuration. These configurations of course are always refined and updated. You break these pieces of configuration into logical
for example a configuration file for NTP configuration, a file for control plane filter and store these in some revision control system. Put aside for the moment whether this is a reasonable way to comprehend deployed configurations. What methods do some of you use to know which version of a configuration you have deployed to a given router for auditing and update purposes? Remarks are a convenient way to do this for ACLs - but I don't have similar mechanics for top level configurations. About a decade ago I thought I'd be super clever and encode versioning information into the snmp location - but that is just awful and there is a much better way everyone is using, right? Flexible commenting on other vendors/platforms make
use sections, this a
bit easier.
Assume that this version encoding perfectly captures what is on the router and that no person is monkeying with the config... version 77 of the control plane filter is the same everywhere.