Switching

Hi

When we will use dot1q-tunneling ether-type 0x8100 or 0x9100 and what is the different between  in the KB 13544 they use 0x8100 and in the technical Doc example they use 0x9100 "http://www.juniper.net/techpubs/en_US/junos9.3/topics/example/qinq-tunneling-ex-series.html" 

To configure Q in Q so in which case we will use them and what is the different

Hi,

0x8100 is standard ethertype for single tagged frames (802.1Q), it can be used(and it is) for QinQ tunneling but you should be careful with other vendors configuration, as defaults vary.

 0x88a8 is the standardized value for QinQ (802.1ad) and I would suggest to use this type instead of 0x9100(non-standard QinQ ethertype), especially in a multivendor environment.

Hi dpapana

so please correct me if I am wrong

 0x88a8 is standardized value and this should be user in multi vendor environment

0x9100 is non-standard  we can use it if only have EX switches

but know I have confusion  now if the 0x8100  it's only for the single tag ethertype how we can use it also as ethertype for QinQ as (in the example)

Thanks for your usual support

0x9100 can be used with other vendors also, the problem is that this value is depricated, other vendors by default send 0x88a8 and therefore it's better to use this standardized value.

0x8100 can be used in QinQ by stacking 2 Vlan tags, in this case both tags are with ethertype 0x8100, the problem is that some devices just need a way do differentiate double tagged frames from single tagged ones.

Regarding QinQ there's a lot of different interpretation, for instance IEEE sees QinQ=802.1ad(0x88a8), while Cisco calls QinQ=802.1Q (the double tagged frames with both tags 0x8100).

Thanks a lot for your valuable information just one more thing   

the  " set ethernet-switching-options dotes-tunneling  ether-type XXXXX " it should be configured in all the path ( services provider ) or just in the edge routers that facing the customer  where the

"set vlans qinqvlan  vlan-id xxx dot1q-tunneling  customer-vlans xxxx "  is configured

You can configure this only on Edge devices.