Mailing List Archive: ASR920 - new lines in config after reboot

ASR920 - new lines in config after reboot

May 16, 2021, 6:27 AM

Post #1 of 3 (450 views)

As strange as the ASR920 routers can behave at times, I've never seen this
one before. Wondering if anyone else has.

We have a remote site with a ASR920-12CZ router running 3.16
(03.16.05.S.155-3.S5) which has been fine for quite a while now (years).
Yesterday there was a power outage at the site and everything was out for
several hours.

Once the power situation was fixed, I went to the site and turned the UPS
back on, powered up the 920, etc. Everything seemed to go fine -- I did
have to reboot the 920 a couple of times to get it to boot, though I've
seen that behavior before (it stalls 80% of the way through the boot, after
it displays the full cisco banner but before it starts bringing interfaces
up). Anyway, it came back up, everything seemed fine. I left.

This morning I noticed that our rancid installation is complaining that the
router's config changed. Of course it did, it rebooted so times will be
different, etc. But I also found lines inserted into each interface's
config.

interface GigabitEthernet0/0/0
description Site-UPS
no ip address
+ ip broadcast-address 0.0.0.0
negotiation auto
service instance 1 ethernet
encapsulation untagged
bridge-domain 1

interface GigabitEthernet0/0/8
description Cust: <Customer name and id>
no ip address
+ ip broadcast-address 0.0.0.0
media-type auto-select
negotiation auto
service instance 56 ethernet
encapsulation untagged
service-policy input 50M
service-policy output 500M
bridge-domain 56

interface BDI1
description Untagged site MGT addresses
ip address 10.0.1.1 255.255.255.0
+ip broadcast-address 10.0.1.0

The "ip broadcast-address" has somehow been added to every interface, both
physical and bridge-domain. In some cases it's not 0.0.0.0, it's the
subnet the interface is on -- though not really the broadcast.

In any event, I was on-site and the only one touching the box. I certainly
didn't add them, and we don't do any ZTP or automated configuration, etc.
Also didn't change the IOS, etc. So I'm trying to find out how it suddenly
got in there.

Shawn
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Re: ASR920 - new lines in config after reboot [ In reply to ]

bryan at shout

May 19, 2021, 1:35 AM

Post #2 of 3 (450 views)

Permalink

That to me smells like a change in your config-register.

Not saying I know how it changed or why, but that is one of the bits.
(0x0400, if I recall correctly.)

On 5/16/21 3:27 PM, Shawn L wrote:
> As strange as the ASR920 routers can behave at times, I've never seen this
> one before. Wondering if anyone else has.
>
> We have a remote site with a ASR920-12CZ router running 3.16
> (03.16.05.S.155-3.S5) which has been fine for quite a while now (years).
> Yesterday there was a power outage at the site and everything was out for
> several hours.
>
> Once the power situation was fixed, I went to the site and turned the UPS
> back on, powered up the 920, etc. Everything seemed to go fine -- I did
> have to reboot the 920 a couple of times to get it to boot, though I've
> seen that behavior before (it stalls 80% of the way through the boot, after
> it displays the full cisco banner but before it starts bringing interfaces
> up). Anyway, it came back up, everything seemed fine. I left.
>
> This morning I noticed that our rancid installation is complaining that the
> router's config changed. Of course it did, it rebooted so times will be
> different, etc. But I also found lines inserted into each interface's
> config.
>
> interface GigabitEthernet0/0/0
> description Site-UPS
> no ip address
> + ip broadcast-address 0.0.0.0
> negotiation auto
> service instance 1 ethernet
> encapsulation untagged
> bridge-domain 1
>
> interface GigabitEthernet0/0/8
> description Cust: <Customer name and id>
> no ip address
> + ip broadcast-address 0.0.0.0
> media-type auto-select
> negotiation auto
> service instance 56 ethernet
> encapsulation untagged
> service-policy input 50M
> service-policy output 500M
> bridge-domain 56
>
> interface BDI1
> description Untagged site MGT addresses
> ip address 10.0.1.1 255.255.255.0
> +ip broadcast-address 10.0.1.0
>
> The "ip broadcast-address" has somehow been added to every interface, both
> physical and bridge-domain. In some cases it's not 0.0.0.0, it's the
> subnet the interface is on -- though not really the broadcast.
>
> In any event, I was on-site and the only one touching the box. I certainly
> didn't add them, and we don't do any ZTP or automated configuration, etc.
> Also didn't change the IOS, etc. So I'm trying to find out how it suddenly
> got in there.
>
> Shawn
> _______________________________________________
> cisco-nsp mailing list cisco-nsp@puck.nether.net
> https://puck.nether.net/mailman/listinfo/cisco-nsp
> archive at http://puck.nether.net/pipermail/cisco-nsp/
>
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Re: ASR920 - new lines in config after reboot [ In reply to ]

shawn at rmrf

May 19, 2021, 3:45 AM

Post #3 of 3 (450 views)

Permalink

Thanks -- someone else suggested that as well, and it does seem to make
sense.

From the logs it appears to have always been 0x2102, but that doesn't mean
that something strange didn't happen or that it's actually telling the
truth about what it's set to. I may have to add this to the list of
strange ASR920 behavior we've been keeping (it seems to be growing).

Shawn

On Wed, May 19, 2021 at 4:35 AM Bryan Holloway <bryan@shout.net> wrote:

> That to me smells like a change in your config-register.
>
> Not saying I know how it changed or why, but that is one of the bits.
> (0x0400, if I recall correctly.)
>
>
> On 5/16/21 3:27 PM, Shawn L wrote:
> > As strange as the ASR920 routers can behave at times, I've never seen
> this
> > one before. Wondering if anyone else has.
> >
> > We have a remote site with a ASR920-12CZ router running 3.16
> > (03.16.05.S.155-3.S5) which has been fine for quite a while now (years).
> > Yesterday there was a power outage at the site and everything was out for
> > several hours.
> >
> > Once the power situation was fixed, I went to the site and turned the UPS
> > back on, powered up the 920, etc. Everything seemed to go fine -- I did
> > have to reboot the 920 a couple of times to get it to boot, though I've
> > seen that behavior before (it stalls 80% of the way through the boot,
> after
> > it displays the full cisco banner but before it starts bringing
> interfaces
> > up). Anyway, it came back up, everything seemed fine. I left.
> >
> > This morning I noticed that our rancid installation is complaining that
> the
> > router's config changed. Of course it did, it rebooted so times will be
> > different, etc. But I also found lines inserted into each interface's
> > config.
> >
> > interface GigabitEthernet0/0/0
> > description Site-UPS
> > no ip address
> > + ip broadcast-address 0.0.0.0
> > negotiation auto
> > service instance 1 ethernet
> > encapsulation untagged
> > bridge-domain 1
> >
> > interface GigabitEthernet0/0/8
> > description Cust: <Customer name and id>
> > no ip address
> > + ip broadcast-address 0.0.0.0
> > media-type auto-select
> > negotiation auto
> > service instance 56 ethernet
> > encapsulation untagged
> > service-policy input 50M
> > service-policy output 500M
> > bridge-domain 56
> >
> > interface BDI1
> > description Untagged site MGT addresses
> > ip address 10.0.1.1 255.255.255.0
> > +ip broadcast-address 10.0.1.0
> >
> > The "ip broadcast-address" has somehow been added to every interface,
> both
> > physical and bridge-domain. In some cases it's not 0.0.0.0, it's the
> > subnet the interface is on -- though not really the broadcast.
> >
> > In any event, I was on-site and the only one touching the box. I
> certainly
> > didn't add them, and we don't do any ZTP or automated configuration, etc.
> > Also didn't change the IOS, etc. So I'm trying to find out how it
> suddenly
> > got in there.
> >
> > Shawn
> > _______________________________________________
> > cisco-nsp mailing list cisco-nsp@puck.nether.net
> > https://puck.nether.net/mailman/listinfo/cisco-nsp
> > archive at http://puck.nether.net/pipermail/cisco-nsp/
> >
>
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