02-08-2007 10:12 AM - edited 03-05-2019 02:14 PM
Hi guys,
I have a setup like my all the switch ports are configured as trunk ports (dot1q)
i have vlans configured on the sever(win2003) (interface)and those are belongs to different vlans.
in that case how i can identify which sever belongs to which vlan from the switch.
"without knowing the server vlan information "
Please post your suggestions
Thanks,
Krishna.
02-08-2007 10:48 AM
Hi Krishna,
I do not fully understand what's being asked, but ....
You can find out what device is on what vlan by investigating the output of the "show mac-address-table [vlan x]" command.
The output can be combined with the output of "show arp" (cisco) or "arp -a" (windows) to match the mac- and ip-addresses. Ping the server IP-adresses before you issue the arp statements.
Regards,
Erik Tamminga
02-08-2007 11:00 AM
Hello Krishna,
If you know the mac address of that server you can go to the switch and issue the command:
show mac-address-table | inc "last few digits of the mac"
You will get on which VLAN this server was captured.
Let me know if this answers your question,
Remark: This is a workarround approach, however, you should know which server is connected to which VLAN because I understood in your scenario the taging of VLANs is done on the Win2003 server.
Regards,
Appreciate your rating,
02-08-2007 11:19 AM
Hi Haddad,
Thanks for your reply
thats what i am looking.
is it possible to test(find) the sever interface whether it support for dot1q tagging or not?
Thanks,
Krishna
02-08-2007 11:25 AM
Hello Krishna,
Go to the interface which is connected to the server and issue the command
switchport mode desirable
switchport trunk encapsulation dot1q
The above will let the switchport to try negotiating trunk via DTP.
Then go to the global configuratio mode and issue the command
show interface trunk
It will show you which interfaces did negotiate as trunk. If the interface negotiated a trunk then the server does support trunking using dot1q tagging. If not then your server interface card does not support it.
Another ways it go to the network card manufacturer webpage and check if the interface model that you have does support trunking or not. Usually, Intel based servers are not shipped with supported interfaces unless specified by customers. VMWARE servers support trunking on their NICs.
Let me know if this answers your question,
Regards,
02-08-2007 11:52 AM
Hi Haddad,
Thanks so much
is it possible do the testing in cisco cat OS ?
Thanks,
Krishna.
02-08-2007 11:58 AM
Hello,
Yes you can do this on Cat OS. Most of the commands are the same however you have to use the "set" before the command. If you want, you can look the CAT OS commands on cisco documentation. The link is:
Then you go the switches types and you choose the model you have and you get all the documentation.
Let me know if you need anything else, ;-)
Regards,
02-08-2007 12:19 PM
Hi Haddad,
I found the commands
i think it should be like this
set trunk 1/2 desirable
set trunk 1/2 on dot1q
sh port 1/2
I think this the way
is there any other options available to check this ?
Thanks for your help
Krishna
02-08-2007 12:24 PM
Hello,
To check which ports are in trunking mode you have to use "show port trunk"
Hope this helps,
Regards,
02-08-2007 12:30 PM
Hi ,
I think it show all the information about the trunk ports which is configured on the switch
however i need to find only about the particular port. whether it is negotiated or not (with dot1q)
I just translated the commands which you have posted on IOS.
Please suggest..
Thanks
Krishna
02-08-2007 12:42 PM
It will be
show port trunk 1/2
This will give you the status of this interface only,
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