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how to enable rspan on a vlan

thenone
thenone asked
on
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Last Modified: 2012-06-27
ok in my 3650 switch I went to

switch(#): vlan database
switch(#): vlan 500

then how do I enable rspan on this vlan?
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Commented:


You need a dedicagted reflector vlan to begin with, here is my config;

SW1
vlan 699
 remote-span
!
monitor session 1 source vlan 4 , 699 rx
monitor session 1 destination interface Fa0/19 ingress vlan 4    (sniffer physical location)
!
SW2
monitor session 1 source vlan 4 rx
monitor session 1 destination remote vlan 699 reflector-port Fa0/7  (use any unused interface)


harbor235 ;}
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Commented:
Sorry,  sw1 was not the physical sniffer location, reflector port is

SW1
vlan 699
 remote-span
!
monitor session 1 source vlan 4 , 699 rx
monitor session 1 destination interface Fa0/19 ingress vlan 4
!
SW2
monitor session 1 source vlan 4 rx
monitor session 1 destination remote vlan 699 reflector-port Fa0/7  (use any unused interface)


harbor235 ;}

Author

Commented:
yes but how to I enable rspan on the vlan that I created. I can only do configs in the vlan database because we don't have vtp setup.
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Commented:


In the example vlan 4 is the monitored vlan, 699 is the reflector vlan. For rspan to work
it needs a source vlan (vlan 4) and to get span from anywhere in the switch mesh you need to get it there via a reflector vlan

harbor235 ;}

Author

Commented:
I understand but does the switch have to be on vtp server mode.

Author

Commented:
The swicth is in client mode?
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Commented:

VTP does not have to be on but is recommended, it does not matter which switch you are on. The chief requirementis that the reflector vlan is availble throughout the switch mesh.

here is a good doc;

http://www.cisco.com/en/US/docs/switches/lan/catalyst6500/catos/5.x/configuration/guide/span.html#wp1020120


harbor235 ;}

Author

Commented:
My question is in order to enable rspan on the vlan the switch has to be in server mode. If I enable server mode will it mess up my current vlan's
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Commented:

no, server mode refers to VTP being enabled and the switch is either a server or client mode for vlan propagation. If you are not using VTP then you need to have all the vlans trunked, VTP is just much simplier. The idea behind rspan is that it does not matter what switch you are on.

harbor235 ;}

Author

Commented:
so basically go into vlan database and then type in vtp server, then go to config t, then set vlan 500 rspan correct?
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Commented:

I am not sure of your topology or the number of vlans you have but be careful here. The question was setting up rspan which i have provided the config for. VTP is another story, If you do not have many vlans this should not be a big deal, however, by default cisco switches are vtp servers, who ever has the lowest mac address takes over and can potentially wipe out the vlan data base.

BE CAREFUL HERE

I would do the follwoing;

Backup configs before hand

Set up a new VTP domain with unique domian name and authentication, that way if you add other switches they will not be in the proper VTP domain and will not join.

set the remaining switches to VTP client mode.

Setup RSPAN as mentioned above.

harbor235 ;}

Author

Commented:
ok we only have 2 switches I am dealing with. Setting up a vtp domain would be an overkill. I have one poe switch that will have traffic monitored. I then have a core swicth with one port that will be do the monitoring. So setting a vtp domain will not work because both switches have different purposes and different configs. If I change both switches to be vtp server and setup vlan with rspan capability won't this work?
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Commented:


Ok, fine, then just make sure th evlans you need are trunked between the switches and add th reflector vlan, VTP is not necessary.

harbor235 ;}

Author

Commented:
evlans you need are trunked between the switches? Do you mean make sure that the vlans are setup the same on both switches?

Author

Commented:
so setup a new vlan on both switches call it 444. Enable rspan on that vlan. Correct?

Author

Commented:
I think I know what you are saying now. Make a new vlan on both switches. Put both swicthes ports into that new vlan. Then create a seperate vlan for the rspan? Correct?
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