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New Member

Linking two SF300-8 switches, and gvrp

Having spent ages trying to propogate VLANs from one SF300 to another, I think that I have finally done it.  It would appear that one has to set up GVRP on both sides of the trunk, AND manually create the VLANs on the slave switch.  I can now successfully ping machines on both switches that share the same VLAN.

However; if I try and ping a machine on the slave switch from outside of the VLAN i.e. from a routed connection on the master switch, it fails, whereas pinging a machine on the master switch succeeds.

What am I doing wrong?

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Green

Linking two SF300-8 switches, and gvrp

Hi Nigel, GVRP is essentially a terrible (and useless) protocol.

GVRP won't assign anything unless it is predefined of what it can assign, the manually configuration/overhead required is greater than just actually configuring the port.

The configuration you mentioned is basically telling me you manually built the trunk as vlan 1 untag, 11 and 42 tag. The GVRP should do that for you if properly set up.

For GVRP to successfully work the port must be sending the GVRP join messages, the receiving interface must be configured to receive the join messages and then the VLAN database of the advertising switch must have those VLAN manually built/defined as they are being carried in the messages...

If you need some configuration assistance, feel free to post what is your goal, I'm sure myself or someone can help you out if you provide a network diagram and config files.

-Tom
Please mark answered for helpful posts

-Tom Please mark answered for helpful posts http://blogs.cisco.com/smallbusiness/
6 REPLIES
New Member

Linking two SF300-8 switches, and gvrp

Hi Nigel, thank you for using our forum, my name is Luis I am part of the Small business Support community. Could you please reach out to our Small Business Support Center and open a Service Request to address this issue? One of our Engineers may be able to work with you and diagnose the root cause. You can find the appropriate contact information for SBSC in the below link.

http://www.cisco.com/en/US/support/tsd_cisco_small_business_support_center_contacts.html

I hope you find this answer useful

Greetings,

Luis Arias.

Cisco Network Support Engineer.

Green

Linking two SF300-8 switches, and gvrp

Hi Nigel, the switches by default are layer 2 and do not permit intervlan communication. Your router device must support both VLAN and/or the appopriate routes for route the subnets. If you are unable to communicate between VLAN it is because the router is not correctly configured at this time.

-Tom
Please mark answered for helpful posts

-Tom Please mark answered for helpful posts http://blogs.cisco.com/smallbusiness/
New Member

Linking two SF300-8 switches, and gvrp

Hi Tom,  Both switches are set to L3. I do now have the setup working, I think that it's beceause i hadn't added "

allowed vlan add 11,42 tagged " to the "Switchport general" line.

What I still do not understand is that GVRP propogates the VLANs to the other switch, but you cannot allocate a port to them because they are dynamic, so what's the point?......am I missing something?

I got around this by creating the VLANs manually, then all was well.

It would really help if there was a section in the reference guide that had an example of two switches linked in this manner, as I'm sure that there must be other people in the same position i.e. started with a single switch and had to add another as their business grows.

Green

Linking two SF300-8 switches, and gvrp

Hi Nigel, GVRP is essentially a terrible (and useless) protocol.

GVRP won't assign anything unless it is predefined of what it can assign, the manually configuration/overhead required is greater than just actually configuring the port.

The configuration you mentioned is basically telling me you manually built the trunk as vlan 1 untag, 11 and 42 tag. The GVRP should do that for you if properly set up.

For GVRP to successfully work the port must be sending the GVRP join messages, the receiving interface must be configured to receive the join messages and then the VLAN database of the advertising switch must have those VLAN manually built/defined as they are being carried in the messages...

If you need some configuration assistance, feel free to post what is your goal, I'm sure myself or someone can help you out if you provide a network diagram and config files.

-Tom
Please mark answered for helpful posts

-Tom Please mark answered for helpful posts http://blogs.cisco.com/smallbusiness/
New Member

Linking two SF300-8 switches, and gvrp

Hi Tom,  I did get to the point where VLANs on switch A were being advertised to switch B, where they were shown as 'dynamic' VLANs, so I think that my GVRP setup is probably correct.  However, on switch B I could not attach any ports to the dynamically discovered VLANs, as they are 'Not created by user' (which is the error message that you get).  So my real question is; what is the point of dynamically learnt VLANs if you can't assign ports to them?

P.S. thanks for your help by the way

Green

Linking two SF300-8 switches, and gvrp

Hi Nigel, if you make a port within the GVRP activation database, the port is standby to receive the GVRP join messages. Meaning the port is essentially locked looking for those advertisements and also advertising that they can join.

So the problem is this... what good does any of this do for you in terms of client connections? In order for GVRP to function outside of the trunk configurations, any device connecting to the switch would have to support GVRP on the network card to be able to dynamically receive VLAN information from the GVRP database.

So essentially, between switches GVRP works ok because both sides support the protocol and give advertisement. But if you assign another port as a GVRP port, the switch side works perfectly well but if the other connecting side (such as a computer) does not support GVRP it doesn't do anything.

So if you need a port facing toward a client side, you need to remove that port from GVRP to manually assign the desired configuration so it can traverse the trunk as you desire.

-Tom
Please mark answered for helpful posts

-Tom Please mark answered for helpful posts http://blogs.cisco.com/smallbusiness/
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