ISIS Question

kafifi13

Hello all. I'm days away from taking my BSCI and i'm trying to go over the little details of each subject. I've already failed this test a couple of times coming somewhat close. 700 was my best score. I feel confidant everytime but this time. Anyway my question is on ISIS. When I do a show clns neighbors and for my SNPA address and I see HDLC listed is that telling me that it's a point to point link? If i were to see a DLCI 301 that is obviously that i'm connected via frame relay. Does that make sense? Just trying to understand the little details.

kalebksp

SNPA (Sub Network Point of Attachment) shows the layer 2 address. Frame-relay uses DLCIs, so that is why it show a DLCI number. If you were to look at the Ethernet SNPA it would be a MAC Address. HDLC doesn't have layer 2 addresses, so it simply says HDLC.

kafifi13

HDLC can be used for both Framing and P2P is that correct?

ccnpninja

for the exam, just know that if you issue "show clns neighbor" et see HDLC, it means that the local router is connected to his neighbor in a point to point fashion, let's say leased line for example. If you see a DLCI number, it means IS-IS is running on Frame-Relay.
HTH