[c-nsp] ISR detects interface status with delay

[Martin T]

In order to illustrate this behavior I made a short video where IOS
detects that interface Fa0/0 went down with almost 13 seconds delay.
Usually this delay is around 5 to 8 seconds, but sometimes up to 15
seconds. Video can be seen here:
https://www.dropbox.com/s/yb9o379935s3hou/20150206_110347.mp4 PHY chip
should detect this within micro- or milliseconds and as seen from the
video, LED's indicating the link status went off immediately when I
removed the cable, but why does it take so long for IOS to detect
this?



thanks,
Martin

On Thu, Feb 5, 2015 at 3:44 PM, Martin T <m4rtntns at gmail.com> wrote:
> Hi,
>
> I have a Cisco WS-C2960G-24TC-L switch(IOS
> c2960-lanbasek9-mz.150-2.SE7.bin) and Cisco 1841 router(IOS
> c1841-advipservicesk9-mz.151-4.M1.bin) connected like this:
>
> sw1[Gi0/3] <-> [Fa0/0]r3
>
> If I pull out the cable from "sw1" port Gi0/3, then "r3" detects this
> with 5 - 7 second delay. I configured "carrier-delay msec 0" under
> "r3" interface Fa0/0, but this did not help. For example here:
> http://s1.postimg.org/9zf76q0el/cable_removed_from_sw1_Gi0_3.png "sw1"
> detects that the port Gi0/3 went down at 15:10:57 - 15:10:58, but "r3"
> detected this 15:11:04 - 15:11:05. Clock in all the devices is exactly
> the same. What might cause such behavior?
>
>
> thanks,
> Martin