More CCNA Questions

• Which ISDN Q-series specification defines the LAPD protocol used on the D channel to encapsulate signalling requests?
  Ans: 1) ITU-T Q.920    2) ITU-T Q.921



• We want to include 6 equal-cost routes to the same subnet in the routing table. How do we achieve this?
  Ans: maximum-paths 6
  The maximum-paths command will include equal-cost routes to the same subnet in the routing table. By default Cisco IOS includes upto 4 equal-cost routes in the routing table, if we need more or less we use maxim-paths nr_of_paths.



• Given the network range 192.168.1.0/24 to 192.168.32.0/24. How many summary routes will be advertised?
  Ans: One.
  We have a block of 32 networks so we can replace this range using route summarization.
  Let's have a look at the 3rd otcet in binary.
  1 0000 0001 2 0000 0010 ... 10 0000 1010 ... 32 0010 0000 Now we can see that the first 2 bits are always the same, so we can now derive a supernet mask for this block. The first two octets are the same and so are the first two bits of the third octet, this will become all 1s in the supernet mask or 1111 1111.1111 1111.1100 0000.0000 0000 or 255.255.192.0. So the route advertised is 192.168.1.0/18



• The administrative distance of OSPF is?
  Ans: 110.
  For other routing protocols, The other values are
  Connected Interface   -   0
  Static Route   -   1
  EIGRP Summary Route   -   5
  External BGP   -   20
  Internal EIGRP   -   90
  IGRP   -   100
  OSPF   -   110
  IS-IS   -   115
  RIP   -   120
  EGP   -   140
  On Demand Routing   -   160
  External EIGRP   -   170
  Internal BGP   -   200