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SG500 Trunk Port to Cisco 3560 Trunk not passing traffic

jwhite
Level 1
Level 1

Hello All!

So i have a very odd situation were a SG500 Trunk port / Uplink port will not communicate with a Cisco cat. 3560 trunk port.   No vlan traffic at all.  ports are live, but nothing will pass through not even vlan 1. 

 

3560 Port config:

interface GigabitEthernet0/48
 description Connection to SG500 Port 49
 switchport trunk encapsulation dot1q
 switchport mode trunk
 switchport nonegotiate
 priority-queue out 
 mls qos trust dscp
!

This port was just built from scratch to try and see if we can get traffic flow.
interface GigabitEthernet0/49

description Connection to SG500 Port 49 Trunk test
 switchport trunk encapsulation dot1q
 switchport mode trunk
 switchport nonegotiate

 

SG500 config:

interface gigabitethernet1/1/49
Switchport mode trunk
switchport trunk allowed vlan 2,3,4,5,6,21,31,51

 

Any thoughts or suggestions would be GREATLY appreciated.  Please feel free to ask any questions needed. I really appreciate it!

 

 

7 Replies 7

Mark Malone
VIP Alumni
VIP Alumni

HI you could try match the trunk on each side see if that fixes it , one side full trunk the other only certain vlans  sg500

Allowed VLANs on trunks: The list of allowed VLANs on a trunk has not been updated with the current VLAN trunking requirements. In this situation, unexpected traffic or no traffic is sent over the trunk.

Thanks.  I did issue the command to the SG500:
Switchport trunk allowed vlan add all

and it just added the defined vlans in the switch.  Must be by design??

did you try hardset the 3560 side then if the sg500 wont allow it, it should really be equal each side of a trunk

Mark,

 

Sure did..  Even issued a command on the 3560 to allow VLAN's 1-1000 just to be safe.  Still no passing traffic.   

Had this also happen on another 3560, same issue no traffic passing.  Odd.  Not an IOS compatibility issue by chance could it?

3560's running 12.2

Thanks again.  

wouldnt have thought it was an ios issue on something so simple , if you do a show int trunk on the 3560 does it show anything

If you set a port on each side to be access can you pass traffic on your default vlan

 

Is the sg switch still in layer 2 mode , show system mode

I'll see if we can pass traffic on VLAN 1 if we plug into just a standard non-trunk port. 

SG is in Layer 3.  Double checked that.

 

Would the Native VLAN have anything to do with it? I don't think so, just double checking. 

camc_8011
Level 1
Level 1

hi jwhite,

 

You could have solved the same stage, and still can not get fixed.

 

Cristobal Marecos

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