1: | |
A: | An Intermediate System is the ISO term for a router. |
2: | |
A: | A Network Protocol Data Unit is the ISO term for a packet. |
3: | |
A: | An L1 router has no direct connections to another area. An L2 router only routes inter-area traffic. An L1/L2 router routes both inter-area and intra-area traffic and acts as an inter-area gateway for L1 routers. |
4: | |
A: | The borders of IS-IS areas are between routers, on links. The borders of OSPF areas are defined by the routers themselves . |
5: | |
A: | The Network Entity Title is an address by which a router identifies both itself and the area in which it resides. |
6: | |
A: | The NSAP Selector should be set to 0x00 in a NET. |
7: | |
A: | The System ID uniquely identifies a router within an IS-IS domain. |
8: | |
A: | The portion of the NET preceding the last seven octets is the area address. |
9: | |
A: | IS-IS does not elect a BDR. |
10: | |
A: | The Pseudonode ID is the last octet of a LAN ID. Its purpose is to distinguish LAN IDs which are originated by a single router which is the DR on multiple LANs. |
11: | |
A: | The MaxAge of an IS-IS LSP is 1200 seconds (20 minutes). |
12: | |
A: | OSPF increments the age up to MaxAge; IS-IS decrements the age down to 0. A new OSPF LSA has an age of 0, whereas a new IS-IS LSP has an age of MaxAge. |
13: | |
A: | The refresh rate of an IS-IS router is 900 seconds (15 minutes). |
14: | |
A: | A Complete Sequence Number Packet contains a full listing of all LSPs in a database. A CSNP is periodically sent by the Designated Router on a broadcast network to maintain database synchronization. |
15: | |
A: | A Partial Sequence Number Packet contains a listing of one or more LSPs. It has two uses: On point-to-point networks, it is used to acknowledge the receipt of LSPs. On broadcast networks, it is used to request LSPs. |
16: | |
A: | An IS-IS router uses the Overload bit to inform its neighbors that it is experiencing a memory overload and cannot store the entire link state database. |
17: | |
A: | The Attached bit is used by L1/L2 routers to inform L1 routers that it is attached to the L2 backbone. |
18: | |
A: | The ISO specifies four metrics: Default, Expense, Delay, and Error. Cisco supports only the Default metric. |
19: | |
A: | The maximum value of any of the IS-IS metrics is 63. |
20: | |
A: | The maximum metric value of an IS-IS route is 1023. |
21: | |
A: | L1 IS-IS metrics apply to intra-area routes, and L2 IS-IS metrics apply to inter-area routes. |
22: | |
A: | Internal metrics apply to routes to destinations within the IS-IS domain. External metrics apply to routes to destinations external to the IS-IS domain. |