When to use save runnning config to startup config?

[christianmj]

Hi Cisco guys

I am very rusty in Cisco switch use.

I have changed the maximum MAC adresses in the port security section on an interface. Should I now save running config to not loose that change if the router reboots?

Could somone please explain to me or link to a document that explains when to use save running config to startup config in generel.

Many thanks in advance                   

[Richard Burts]

I generally use the principle that we should not save the changes immediately after making them and should verify that they have the desired effect and then should save the changes.

HTH

Rick

[John Blakley]

I agree with Rick...make sure it's doing what you want before you save changes. A good use of that would be configuring aaa without testing. If you make a change to that, save changes, log out, and then try to log back in and you realize that you can't, then you've hosed up the config and will have to console in to fix the change, or worst case scenario would have to do a password recovery...

HTH,
John

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[christianmj]

Thank you Richard and John for your replys. I am sure that the change has the desired effect. If I do not save the change to startup config, will the change go away if the switch reboots?

My question is, do you alway have to save the changes - after the effect is verified, or in my case, does the switch remember the port security change without me having to save the configuration to startup config.

[John Blakley]

In all cases, you'll need to save the config in order to survive a reboot. Port security, depending on the change is a little different. You can enable port security on a port and have it learn addresses. If you don't use the sticky option when learning the mac addresses on the port, or if you don't manually specify the mac addresses that should be on the port, the switch will not remember the addresses that it learned after the reboot. If you use the sticky option, or manually specify the mac addresses and then save the config, the mac addresses that were learned are saved to the config and will be there after a reboot.

HTH,
John

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[christianmj]

Thanks John for your reply

I have changed the maximum max adresses on an interface with port security. Will that change persist after a reboot of the switch if I do not save the running configuration to startup configuration after the change?

[John Blakley · Accepted solution]

That particular change will not stay if you don't save the config.

HTH,
John

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