Unanswered Question
May 28th, 2009


i ' ve a problem.

There 2 LAN , Site 1 and Site 2

Site 1 and site 2 have a number 1 cisco 3550 l3 and number 2 cisco 2950

cisco 3550 l3 of site 1 is connect to a cisco 3550 le of site 2 with a routed port.

I must realize a Remote SPAN from site 2 to site 1.

i must create in all two site a new vlan.

in the site 2 there is a pc that i want to sniffing.

I create a remote SPAN port with source the port of pc that i want to snif and destination a vlan.

in the other site i must do to the same with a sorce of new vlan and the destination the fastethernet where i want to connect my pc for to snif.


how can i do for to CONNECT THE new vlan (for example vlan id 10) of two site?

I THINK a TUNNEL GRE from 2 site but i down't know if is a good solution.

WHAT IS a mode of to connect a vlan of two sites connect to level3 ?

thanks for your help


I have this problem too.
0 votes
  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 0 (0 ratings)
fcostalunga Fri, 05/29/2009 - 00:22

i've read the explain but i don't find the solution a my problem.

I must connect a singe vlan of 2 sites.

the vlan id is the number 50.

i must create a remote span using the vlan 50 and with a tunnet i hope that pass all traffic.

I don't see an example of this situation.

The 2 sites in connected in ospf with a fiber , and gigaport set in router port.



Giuseppe Larosa Fri, 05/29/2009 - 02:16

Hello Francesco,

you need to connect a L2 trunk port of switchA site A to an interface on RA.

the trunk has to carry vlan50 in the list of allowed vlans.

RA has an 802.1Q subinterface like

int gi0/0.50

encapsulation dot1q 50

! xconnect commands here


on the other side you need to do the same:

switchB connect with trunk to RB

and RB has to be configured in similar way.

note: on both sides the subinterface has no ip address.

The L2TPv3 tunnel carries frames with tag 50 to the other router.

the scenario should be:

SwitchA--RA --- IP WAN --- RB--SwitchB

RA |<------------------->|RB


Hope to help



This Discussion