CDP neighbor detail

[Mohd Khairul Nizam]

I'm trying to trace the connection between Main SW and Distribution SW

from main SW , i follow the sh cdp neig detail
but when i ssh to the IP of the neighbor SW, it seem like it going to different SW

How is it possible ? 

[Daniele Giordano]

Hi, could be a duplicated IP? Or an overlapped IP between vlan 1 and vlan 8?

Can you try to change the IP of the switch Behind_sariffdesk#?

Regards.

[mohammed01701]

Hi!

Behind_sariffdesk is this WS-C3750-48P switch, which is connected on the interface GigabitEthernet2/1/2 on slmyklmcr-SSMY? If that is yes then every thing is correct:

Vlan 1 is only Native.. 

The question is which interface is directy connect to the  Distribution SW?

/Mohammed

[Mohd Khairul Nizam]

No it is not correct.

From the CDP neighbor, you expect the WS-C3750-48P is suppose to be slmyklm22-02 not Behind_sariffdesk SW.

that why, if i ssh to 10.49.220.56 i suppose to get slmyklm22-02.

[mohammed01701]

Hi!

Can you post show cdp nei from slmyklm22-02?

What switch is Behind_sariffdesk, can you also post show cdp nei and show version?

/Mohammed

[STEPAN JANKOVIC]

Hello,

It is true that 10.49.220.56 is configured on slmyklm22-02, but it is also true that it effectively belongs to Behind_sariffdesk (Vlan 8) :-) 

I would encourage you to get more insight by evaluating arp tables and mac-address tables. When you ping 10.49.220.56, you will see its MAC address in ARP table. Then you can check, where is this MAC address located by evaluating MAC address tables of switches. Most probably you will see again, that this belongs to Behind_sariffdesk. You will need to examine slmyklm22-02 by console, because it may be misconfigured for remote access.

Regards

Stepan

[STEPAN JANKOVIC]

Hello,

what is the best next efective step: break into slmyklm22-02 (skip config, boot without it, modify paswords and console settings, orrect ip adress configuration etc....(outage)). This will definitely solve the problem.

There are also ways how to put behind_shariffdesk out of service. Fastest way is to disconect it from network for a short while and try again to connect to slmyklm22-02. You may clear your ARP table after disonnecting behind_shariffdesk and before conneting to slmyklm22-02. If you will not be able to connect, you will have to break into misconfigured slmyklm22-02 and review config.

Regards

Stepan