About CCNA ICND2 certification: ICND2 (640-816), short for Interconnecting Cisco Networking Devices Part
2 is required to be passed when a candidate is pursuing two-exam CCNA
certification path. The other exam that needs to be passed is CCENT. This
exam tests a candidate's knowledge and skills required to successfully
install, operate, and troubleshoot a small to medium size enterprise branch
network. The exam covers topics on VLSM and IPv6 addressing; extending
switched networks with VLANs; configuring, verifying and troubleshooting
VLANs; the VTP, RSTP, OSPF and EIGRP protocols; determining IP routes;
managing IP traffic with access lists; NAT and DHCP; establishing point-to-
point connections; and establishing Frame Relay connections.
- ISL: A Cisco proprietary trunking protocol, associated with
Ethernet.. Supported by Catalyst switches and routers. ISL uses
"encapsulation" of Ethernet frame for multiplexing multiple VLANs
over a trunk line.
- 802.1Q: This is an IEEE standard for the VLAN
trunking protocols, associated with Ethernet. A VLAN identifier is inserted
into the frame header, a technique called frame tagging.
- 802.10: A Cisco
proprietary method for transporting VLAN information inside the standard
802.10 FDDI frames.
- LANE : LANE stands for LAN Emulation and is
associated with ATM. This is an IEEE standard for transporting frames over
ATM networks.
To verify any configuration change, "show vtp" privileged
executive command can be used. This command displays, among other things,
VTP domain name, VTP password if any, VTP pruning mode (enabled or
disabled) and the IP address of the device that last modified the
configuration.
- NAT allows several hosts be connected to Internet by using fewer
globally unique IP addresses. This in turn results in conserving the scarce
public IP addresses. The terms public / global is used in the sense that
the IP addresses are globally unique and officially registered.
- NAT
supports load sharing on inside machines. The inside machines are accessed
in a round robin fashion, thus sharing load.
- NAT offers some degree of
security since IP addresses are not easily traceable. This is because, the
actual host IP that is accessing the Internet is translated into outside IP
address and vice versa. Thus, NAT offers protection against hacking.
- One
disadvantage of NAT is that it increases delay. This is obvious since
address translation is involved.
- Another disadvantage of NAT is that,
when an application uses physical IP address, it may not function properly.
This is because the physical IP address is changed by NAT.
1. The command: show frame-relay pvc 100 displays the traffic statistics
for PVC 100. The out put include input packets, output packets, BECN
packets, FECN packets, etc.
2. The command show interface serial 0 displays
whether the interface is up, line protocol is up, LMI type, LMI DLCI, among
other details.
3. The command frame-relay lmi displays the LMI traffic
statistics.
4. The command that displays the current map entries is: show
frame-relay map.
The command 'show ip ospf interfaces' shows the summary information for
OSPF interfaces. The information provided include autonomous system number,
router id, designated router id, backup designated router id, hello time,
and adjacent neighbors.