[c-nsp] ISIS P2P Behaviour with L2 Switch

[Dhamija Amit]

 Hi

I have a below topology in which Router R1 is having Trunk connectivity to Layer 2 Switch and R2,R3 and R4 with access port connectivity with L2 switch with vlans 10 for R2 , 20 for R3 and 30 for R4.

                   --->(vlan 30) R4
R1 <---[layer 2 SW] ---> (vlan 10) R2
                   --->( vlan 20) R3

Now i am establishing ISIS P2P neighbourship with R1-R2 , R1-R3 and R1-R4.

When R1 sends ISIS hello ( let's say it's a P2P so it want to send hello to R2 only which it includes in IPV4 interface address TLV), When it comes to Switch , since ISIS Layer 2 Ethernet frame doesn't consists of any specific VLAN header when frame comes on switch , then from switch point of view it has no means to identify it comes from R1 (Vlan 10) , then will this hello will be broadcast to all the remaining routers R2,R3 and R4 ( as destination address is fixed multicast-address and there is no CAM table for it)  ?? or else how switch will ensure that this specific hello packet is originated from vlan 10 and should only be send to R2.??

Thanks
Amit