Trunking issue

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Jun 19th, 2008
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Issue between two switches.

Switch1 is uplink switch (WS-C3524-XL),FastEthernet0/24 in vlan 1 by default, is connected to Switch2(WS-C2960-48TT-L) to Gi0/1.

When i put Gi0/1 in

interface GigabitEthernet0/1

switchport mode trunk

speed 100


it does not make any change , but when i put Switch1 port f0/24 into

switch port mode trunk i lost the connectivity.

i suspect issue in switch2 g0/1 port because when it is configured for trunk or in vlan1 i do not see any change.

vlan1 is management vlan .

pls suggest !!!

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thotsaphon Thu, 06/19/2008 - 10:36
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Can you post the errors you mentioned?

Are all interfaces up?

please post a "show int status o" command n both interfaces?

Hopes you are testing connections from the vlan1. If not, Have all switches been added the vlans?



rohitraizaday Thu, 06/19/2008 - 19:32
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Both switch have same vlan database, issue is all the vlan are not communicating except vlan1.

thotsaphon Fri, 06/20/2008 - 04:01
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I should use either "dot1q" or "ISL" on both switches. Seems you are using Vlan1 as a native vlan. So dot1q will let vlan1 go without tagging but ISL does. Let's check WS-C3524-XL.

please do "sh inter trunk" command.That will explore what is happening.



rohitraizaday Fri, 06/20/2008 - 05:19
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Thanks for you help, but issue has been fixed.

uplink switch port was not supporting truck.

After changing port it start working.


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