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Community Member

VTP configuration

Guys,

After reviewing our network I have found that we have switches configured as server, client and transparent. There is no obvious reason why the guy who looked after the network has done this, I think he has just forgotten to review the config of each switch after it has been implemented.

We have nine switches in our environment. The weekend just gone I reviewed the configured, configured all switches bar one as transparent, then configured the core switch with the correct VLAN information, confirmed and tested this, then set each device to client and let them pick up the information from the core device. After doing this I set them back to transparent. I know I will have to do this each time I add a new VLAN but the likelihood of me doing this is only small in the future. So now mey configuration is one server and eight transparent.

Am I exposing myself at all by only having one server? Should I have two configured as server? As I have understood this is not necessary? Although I have been proven wrong many a time before!

Thanks

Darren

1 ACCEPTED SOLUTION

Accepted Solutions

Re: VTP configuration

In addition to the good information by Glen, I find that Transparent mode gives you more control over where you extend your broadcast domains. In such sitations you are specifically required to configure the vlan on switches.

Therefore transparent mode is better suited to static enviroments where you are not constantly moving ports between vlans across access switches.

In your case, it is not necessary to configure the switch as a client in order to learn additional vlans.

Once the switch has learned all the VLANs through VTP and then you subsequently change the mode back to transparent, any additional vlans can be added manually to the switch(s)

It is alway good practice to ensure that VLANs are cleared of trunks where the are not necessary. If certain VLANs are not necessary at the edge, then VTP pruning should be enabled.

It is generally recommended that you should have two VTP server within the domain, specifically for redundancy purposes.

Previously most switches default to VTP server, therefore it is always prudent to ensure that you check VTP mode and revision before adding it to the network.

However, if your network remains constant and hosts are generally assigned geographically then there is little advantage in using or configuring switches as VTP clients.

I would not expect new VLANs to be added to the core device and then trunked to all access-switches. Otherwise broadcasts will be flooded across all trunks which have that VLAN memeber where the broadcast originated.

HTH

Allan.

4 REPLIES
Purple

Re: VTP configuration

If you want to just create vlans on the server and have them propagated then run server/client . If you leave the others as transparent then you would have to manually create the vlans on all the transparent switches . If you run client server then yes it is a good idea to run 2 servers . Choose one design or the other , either client/server or make everything transparent.

Re: VTP configuration

In addition to the good information by Glen, I find that Transparent mode gives you more control over where you extend your broadcast domains. In such sitations you are specifically required to configure the vlan on switches.

Therefore transparent mode is better suited to static enviroments where you are not constantly moving ports between vlans across access switches.

In your case, it is not necessary to configure the switch as a client in order to learn additional vlans.

Once the switch has learned all the VLANs through VTP and then you subsequently change the mode back to transparent, any additional vlans can be added manually to the switch(s)

It is alway good practice to ensure that VLANs are cleared of trunks where the are not necessary. If certain VLANs are not necessary at the edge, then VTP pruning should be enabled.

It is generally recommended that you should have two VTP server within the domain, specifically for redundancy purposes.

Previously most switches default to VTP server, therefore it is always prudent to ensure that you check VTP mode and revision before adding it to the network.

However, if your network remains constant and hosts are generally assigned geographically then there is little advantage in using or configuring switches as VTP clients.

I would not expect new VLANs to be added to the core device and then trunked to all access-switches. Otherwise broadcasts will be flooded across all trunks which have that VLAN memeber where the broadcast originated.

HTH

Allan.

Community Member

Re: VTP configuration

Guys,

Thanks as always for your valuable input.

I have decided to convert one of the other switches currently in 'transparent' mode to 'server'. All others will be left in this mode (transparent).

Cheers,

Darren

Community Member

Re: VTP configuration

Hi,

I have some switches running server/client mode. In case I want to chagne VTP mode to transparent, Can i straight away go ahead in production netowrk ? Will that impact any way on existing VLAN database of client/server switch ?

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