![]() ![]() Once the IS-IS demon get enabled each router builds its IIH for the supported levels and send them out all the IS-IS capable interfaces (ISO enabled Interfaces in JunOS and CLNS enabled interfaces in IOS), these hellos or PDUs are carrying the desired information to negotiate the protocol parameters, these parameters include: IS-IS has two hierarchical levels (L1 and L2) and two network types (Point-to-Point and Broadcast) so it's essential to have different types of hello messages or PDUs for serve these networks since the data-link layer for broadcast and P2P links have different style of addressing so they need different treatment, due to this differences there are three IIH PDUs and they are identified in the IS-IS PDU Type field in the IS-IS 8-bit common header that is attached to all the IS-IS messages as the following:Įach of which acting slightly different, Level1 and Level-2 LAN hellos or PDUs are used in broadcast network, whereas P2P hello is used in P2P links (P2P hellos can be used on Ethernet links in some circumstance). ![]() Like other routing and signaling protocols IS-IS has built-in automatic neighbor discovery mechanism which is known by IIHs (IS-IS Hello PDUs), because IS-IS is not IP based protocol the IIH PDUs and all other IS-IS PDUs are directly encapsulated on the data-link layer. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |