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Configuration changes 11 years 6 months ago #33051

Hi all,

For a long time I have this question with me that I wanted to get an explanation of.
Basically, I have worked in a Network Operation Center (NOC) as first line support, and often I get phone calls complaining that certain IP addresses are unreachable. After checking that all physical connections are fine and restarting their router still does not help, this is then handed to the first line support people. And what they often do is make minor changes to the configuration and it works.
So now sometimes I ask myself, do configurations in router change automatically? if this router never had a problem before and was working fine, how come suddenly it doesn't work any more? And administrators have to add or remove something from the configuration file?? So does this have to do with people getting into the config and mess around and then exit back? Seems a bit weird to me...

So what is the cause for a router that always was working, and to suddenly not functioning properly any more, regarding the configuration file? :?:
Kenneth Chong

are we talking about... 11 years 6 months ago #33087

Hello Kchong and how u doing.

Well since u reboot client equipment from ur side (NOC) what equipment are we talking about here? is it Link star Modem, Hughes Modem, IDirect series Modem, .... (VSAT Network) or radio equipments like alvarion, mikrotik and others?

I have had alot of issues with my clients who run on IDirect modems. There have always been complaints from Clients using IDirect Modems here in My country. Concerning the issue of loosing a config? well u knw IDirect Modem Routers make use of Option Files, Link star Modems u have to commission with the Parameters Fobsky supplies and i think Hughes makes use of Option file too.

Now for what will make a modem / router loose it's config well may be someone is telnetting into ur equipment. Most Installers on site forget to change default password.

You see it's just like OPSEC (Operations Security). We have to trash all areas of leak, areas we feel are vulnerable and thus analyze and solve.

Holla Back Man

C0DE - 3

c0de - 3
Take Responsibility! Don't let failures define you

HI.. 11 years 5 months ago #33103

Well i'm just talking about cisco routers.
It's just sometimes strange for me why suddenly some routes or servers are unreachable, while it was always working.. And then I see administrators getting into the configuration file and do some changes and it works..

So once again, my question is does these configuration change by itself? Because before it was always working...

Kenneth Chong

Mr Chong... 11 years 5 months ago #33107

Honorable Mr Chong 5 out of 100 routers / devices encounter config errors. Now to answer ur question configurations can not alter nor change them selves except the router firmware is outdated. Well i have not heard nor experienced a cisco router altering it's config by it self except some other Admin does it. (Which Cisco router are we talking about? Linksys by Cisco or the Main Cisco router it self)

In Sum Routers cant loose its config (except bad firmware issues)..

Which Cisco equipment are u experiencing this issue.

Holla Back KChong

C0DE - 3

c0de - 3
Take Responsibility! Don't let failures define you

Re: Configuration changes 11 years 5 months ago #33114

The answer is... it depends...
Config may have been altered by another admin.
The new running config may not have been saved so the config is vulnerable to a power cycle.
In some cases getting your copy commands can screw things up, like typing copy start run instead of copy run start...
There could be an interface issue with an interface experiencing errors and going in to error_disable mode, or maybe it's not actually the router at all and the admins are telnetting to a switch and unshutting Interface Vlan 1 (or some other Interface Vlan if it's a L3 switch) which may have been erroneously shut down, although again, that'd be another admin doing something he maybe shouldn't be doing.

It'd be handy to know precicely what sort of device we're talking about here, and better yet, what commands are being executed ;)

hi 11 years 5 months ago #33122

Ok, thanks guys for the explanation. It's a little bit more clear for me now...
Kenneth Chong
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