i have Two building with own L3 and L2 network

eng.bandar · ‎07-21-2011

I have two buildings in the same city, there are in each building a private network

each building has

STP and VTP
L3 and L2
VLans

First building using 6509 as L3 without juniper dives

Second building using 6509 as L2 and using juniper as L3

We have fiber optic connect two buildings together

How we can connect those two networks without any Impact in the both networks

i will but diagram and some config

Jon Marshall · ‎07-21-2011

If you do not need the same vlan in both buildings and it sounds like you don't because they are not connected at the moment then i would connect them using either -

1) multiple (2) L3 links

or

2) a L3 etherchannel

so you would route between the 2 buildings. Use a /30 subnet for the IP addressing at each end or 2 x /30 networks if you use multiple links. Then run OSPF between the 6500 and the Juniper L3 switch.

I would recommend against using L2 because of extending the L2 domain between the buildings means STP will have to run over the links and there may be inconsistencies between Cisco and Juniper implementations of STP.

Jon