Difference between %LINK-5-UPDOWN and %LINEPROTO-5-UPDOWN in Switch ?

[akshaydeeti1996]

Hi Everyone,

Can someone please help me understand below ?

1. Explanation on %LINK-5-UPDOWN message ?

2. Explanation on %LINEPROTO-5-UPDOWN message ?

3. Scenario when ONLY %LINK-5-UPDOWN occurs ?

4. Scenario when ONLY %LINEPROTO-5-UPDOWN occurs ?

5. Scenario when both %LINK-5-UPDOWN and %LINEPROTO-5-UPDOWN will occur ?

Thank you for reading !!

[balaji.bandi]

%LINK-5

notifications

5

Normal but significant condition

LOG_NOTICE

1. Explanation on %LINK-5-UPDOWN message ?   - After this, you see UP or DOWN - this means Physical port UP or Down

2. Explanation on %LINEPROTO-5-UPDOWN message ?  - After this, you see UP or DOWN - this means  Link protocol  UP or Down

3. Scenario when ONLY %LINK-5-UPDOWN occurs ?  - same as above if the Physical Interface goes down, the protocol automatically goes down associated with Interface.

4. Scenario when ONLY %LINEPROTO-5-UPDOWN occurs ?  - same as above  - depends on partner status.

5. Scenario when both %LINK-5-UPDOWN and %LINEPROTO-5-UPDOWN will occur ?  - Link protocol UP Down can be based on Physical Interface status/ also with Partner negotiation.

[akshaydeeti1996]

Thanks for your response Balaji.

Let's say, Port1 of a switch is connected to a PC with ethernet cable. At this point, both %LINK-5-UPDOWN and %LINEPROTO-5-UPDOWN will occur. Correct ?

Now, the cable is ONLY unplugged from PC (but is still plugged in Port1 of switch). At this point, ONLY %LINEPROTO-5-UPDOWN will occur. Correct ?

Regards,

Akshay

[balaji.bandi]

This what happens when the device connected to port go down :

%LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet2/0/37, changed state to down
%LINK-3-UPDOWN: Interface GigabitEthernet2/0/37, changed state to down
%LINK-3-UPDOWN: Interface GigabitEthernet2/0/37, changed state to up
%LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet2/0/37, changed state to up

[akshaydeeti1996]

Balaji,

So, what is the scenario when ONLY "%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/1, changed state to down" message is generated.

In your first response, you have mentioned that "depends on the partner status". Can you please elaborate more on what is the partner status ? I want to simulate this in my lab.

In your second response, I see that both %LINEPROTO-5-UPDOWN and %LINK-3-UPDOWN messages are generated.

Thanks,

Akshay.

[MHM Cisco World]

protocol down, you can use serial and use one side PPP and other side HDLC and then you will see the physical is up but protocol is down.
that one case.