THAI CPE

Spanning Tree Protocol (STP), สาเหตุที่ทำให้เกิด loop, การหา Root Bridge, Mode การทำงาน, Blocking,



Managing Configuration Files Configuration Guide, Cisco IOS XE Release 3S

• [li]Given the IP address 172.16.170.15 255.255.224.0, the subnet = 172.16.160.0/19, the host IP address range = 172.16.160.1 to 172.16.191.254, and the subnet broadcast IP address = 172.16.191.255
  
  [/li]
  [li]
  
  7 collision domains and 2 broadcast domains shown in the exhibit.
  
  [/li]
  [li]
  
  5 collision domains and 2 broadcast domains shown in the exhibit.
  
  [/li]
  [li]10.159.255.254/13, 10.158.255.255/13 and 10.153.0.1/13 are valid for hosts that belong to the 10.152.0.0/13 subnet.
  
  [/li]
  [li]The ff00::/8 prefix denotes a multicast type of IPv6 address.
  
  [/li]
  [li]With IPv6, for router and prefix discovery purpose are router solicitation and router advertisement used.
  
  [/li]
  [li]The first 3 bits IPv6 global unicast addresses is 001.
  
  [/li]
  [li]Given the IP address 10.106.170.145 255.248.0.0, subnet = 10.104.0.0/13, host IP address range = 10.104.0.1 to 10.111.255.254, and the subnet broadcast IP address = 10.111.255.255
  
  [/li]
  [li]Robert is sending an instant message to Mary. The message will be broken into a series of packets that will traverse all network devices.
  
  
  
  The source MAC = 0000.000c.0123, source IP = 10.1.2.2, destination MAC = 0000.000c.0124, and destination IP = 10.1.3.3 that will populate these packets as they are forwarded from Router2 to Router1.
  
  [/li]
  [li]Frame Relay is Layer 2 WAN protocol uses DLCI as the virtual circuit identifier.
  
  [/li]
  [li]Packet over SONET:
  The Cisco POS interface supports Cisco HDLC and PPP encapsulation.
  The Layer 2 frame is encapsulated into a generic HDLC header (not Cisco proprietary HDLC) and placed into the appropriate SONET Payload Envelope.
  
  [/li]
  [li]GRE + IPsec is mechanisms are often used together to allow dynamic routing over a secured site-to-site VPN tunnel
  
  [/li]
  [li]IPv4 DHCP operations:
  If the DHCP clients and servers are on the same subnet, DHCP uses UDP broadcasts to communicate with the clients and servers.
  If the client and server are on different subnets, DHCPDISCOVER and DHCPREQUEST messages are sent via UDP broadcasts, but DHCPOFFER and DHCPACK messages are unicast.
  
  [/li]
  [li]VRF is Cisco router feature allows multiple independent routing table instances to co-exist within the same router at the same time.
  
  [/li]
  [li]Refer to the exhibit.
  
  
  
  Company 1 has merged with Company 2. Company 1 is using RIPv2 as its IGP and Company 2 is using EIGRP as its IGP. EIGRP also is running between R1 and R2 over the WAN link.
  The Company 1 RIP routes appear as external EIGRP routes within Company 2.
  The Company 2 EIGRP routes appear as RIPv2 routes within Company 1.
  Configure mutual route redistribution between RIPv2 and EIGRP on the R1 router is action must be taken.
  
  [/li]
  [li]Statements about these partial Cisco IOS/IOS-XE configurations:
  

  interface e0
  ip address 192.168.1.1 255.255.255.0
  ip nat outside
  !
  interface e1
  ip address 10.1.1.1 255.255.255.0
  ip nat inside
  !
  ip nat inside source static 10.1.1.2 192.168.1.2

  
  10.1.1.2 is the inside local address.
  This is an example of static one-to-one Network Address Translation.
  
  [/li]
  [li]

  interface Ethernet0
  ip address 192.168.3.1 255.255.255.0
  ip nat inside
  !
  interface Ethernet1
  ip address 192.168.4.1 255.255.255.0
  ip nat inside
  !
  interface Serial0
  ip address 172.17.38.1 255.255.255.0
  ip nat outside
  !
  ip nat inside source list 1 interface Serial0 overload
  !
  access-list 1 permit 192.168.3.0 0.0.0.255
  access-list 1 permit 192.168.4.0 0.0.0.255

  
  Configuration is necessary to support this output:
  

  RouterX# show ip nat translations
  
  Pro  Inside global        Inside local      Outside local    Outside global
  TCP  172.17.38.1:1050    192.168.3.7:1050  10.1.1.1:23      10.1.1.1:23
  TCP  172.17.38.1:1776    192.168.4.12:1776  10.2.2.2:25      10.2.2.2:25

  
  
  [/li]
  [li]Neighbor discovery protocol in ICMPv6 is IPv6 feature replaced and enhanced the IPv4 ARP functions.
  
  [/li]
  [li]DSL-based Internet services for residential users:
  At the DSL service provider location, a DSLAM is used to terminate and then aggregate the DSL connections over an ATM network.
  The most commonly installed DSL variant for residential deployments is ADSL.
  Most residential deployments use PPPoE encapsulation where the end user PC or the DSL CPE will require a PPP username and password configuration.
  
  [/li]
  [li]Given the Class C IP network of 192.168.1.0, using VLSM, subnets meet the requirements in the exhibit:
  
  
  
  192.168.1.0/27
  192.168.1.32/27
  192.168.1.64/28
  192.168.1.80/28
  192.168.1.96/30
  
  [/li]
  [li]Refer to the exhibit:
  
  
  
  Transport and application layers of the TCP/IP model operates end-to-end (Host A to Host B).
  
  [/li]
  [li]Applications require the network to have the least amount of jitter, delay, and packet loss:
  VoIP
  Cisco TelePresence
  
  [/li]
  [li]per-vlan rapid spanning tree (rapid-pvst) is the default spanning-tree mode of an NNI port on a Cisco ME3400 switch.
  
  [/li]
  [li]Transparent bridging operations:
  A bridge operates at the data link layer.
  A bridge sends unknown unicast frames out on all ports except the incoming port.
  
  [/li]
  [li]According to this show output:
  

  SW1#show port-security interface fa0/1
  
  Port Security              : Enabled
  Port Status                : Secure-up
  Violation Mode            : Shutdown
  Aging Time                : 0 mins
  Aging Type                : Absolute
  SecureStatic Address Aging : Disabled
  Maximum MAC Addresses      : 10
  Total MAC Addresses        : 1
  Configured MAC Addresses  : 0
  Sticky MAC Addresses      : 0
  Last Source Address:Vlan  : 1110.353f.c091:2
  Security Violation Count  : 0

  
  Dynamically learned MAC addresses on the port that are stored in the running configuration.[/li]

B-)

[li]The permit 172.16.32.0 0.0.15.255 access-list entry permits exactly 172.16.32.0 to 172.16.47.255 IP address range.

[/li]
[li]On the Cisco ME 3400 switch, spanning tree is enabled by default on NNI type of switch port.

[/li]
[li]Refer to the two show output examples below. The switch with the e8ba.70b5.7180 MAC address is the root bridge for VLAN 80.

[img]http://dc662.4shared.com/img/xYhQhUPV/s3/sptn2.JPG[/img]

[/li]
[li]Refer to the Cisco IOS XR commands exhibit.
[quote]RP/0/RSP0/CPU0:PE7#install activate disk0:asr9k-video-p-4.1.0
                                    ^
% Invalid input detected at '^' marker

RP/0/RSP0/CPU0:PE7#show user all
Tue Sep 20 21:39:00.331 UTC
Username: admin
Groups: root-system
<output omitted>[/quote]
The router administrator is trying to activate a software package on the router but is not able to do so. The router needs to be in the admin EXEC mode.

[/li]
[li]During the BGP route selection process on Cisco routers, weight is BGP attribute examined first, to determine the best path to use.

[/li]
[li]NSP is type of service provider responsible for offering backbone connectivity services to other service providers.

[/li]
[li]Cisco IP NGN service providers can offer multiple services to their customers by using IP/MPLS is type of technology in their core networks.

[/li]
[li]ISPs use BGP is protocol to establish peering sessions in an Internet exchange point environment.

[/li]
[li]You are enabling OSPF on a router and notice that all the Fast Ethernet and the Gigabit Ethernet interfaces have the same OSPF cost of 1. Change the OSPF auto-cost reference bandwidth is single configuration can make in router ospf configuration mode so that the Fast Ethernet interfaces have a higher OSPF cost than the Gigabit Ethernet interfaces.

[/li]
[li]On Cisco IOS XR software.
[quote]router ospf 1
area 0
  interface gi0/0/0/0[/quote]
Is set of commands enables OSPF area 0 on the Gi0/0/0/0 interface that has an IPv4 IP address.

[/li]
[li]Statements about OSPFv2 or OSPFv3 authentication:
OSPFv3 uses IPsec for authentication and encryption.
On Cisco IOS XR platforms, OSPFv3 authentication can be configured at the OSPF routing process, area, or interface level.
OSPF authentication on Cisco IOS and IOS XE platforms can be configured per area or per interface.

[/li]
[li]In IS-IS routing, the NSEL must always be 00 to identify the router.

[/li]
[li]You have just enabled IS-IS on the lab testing network. You notice that IS-IS is not using the optimal path selection based on the interface bandwidth. Currently, the IS-IS routing process seems to be selecting the best path based on the hop count.
Change the default IS-IS metric on each of the router interfaces to better correspond to the interface bandwidth is configuration change can make to cause IS-IS to select the optimal path based on the interface bandwidth.

[/li]
[li]You have installed a new router and configured OSPF on it. However, this new router is not able to establish an OSPF neighbor relationship with the neighbor OSPF router. Conditions could cause this problem:
Mismatched OSPF area ID between the new router and the neighbor router.
Mismatched OSPF hello/dead interval between the new router and the neighbor router.
Mismatched OSPF authentication data between the new router and the neighbor router.
Mismatched interface MTU between the new router and the neighbor router.

[/li]
[li]Refer to the Cisco IOS XR configuration:
[quote]router isis 1
net 49.0001.0100.0200.1001.00
address-family ipv4 unicast
  metric-style wide
address-family ipv6 unicast
  metric-style wide[/quote]
This router belongs to area ID 0001.

[/li]
[li]MPLS PHP is implemented to increase the performance on the egress edge LSR. PHP allows the egress edge LSR to perform only one lookup to route the IP packet based on destination IP address and routing table.

[/li]
[li]Refer to the exhibit.

[img]http://image.free.in.th/z/it/smpls.gif[/img]

MPLS LDP operations:
The incoming label for 10.2.10.1/32 is 16010 (which is allocated by the local router), and the outgoing label is 22 (as advertised by the next-hop router).
The ImpNull outgoing label for the 192.168.102.0/24 network means that the outgoing label should be removed when sending packets to the 192.168.112.40 next-hop router, when the incoming label is 16003.
The outgoing label of 22 for 10.2.10.1/32 is learned from the 192.168.112.40 LDP neighbor.

[/li]
[li]On Cisco IOS XR software, LDP is enabled on each interface, using the interface command under mpls ldp (MPLS LDP configuration mode).

[/li]
[li]REP configurations on a Cisco ME 3400 switch port:
The port where the segment terminates is called the edge port.
With REP, at least one port is always blocked in any given segment-that is, the alternate port.
Use the rep segment number command to enable REP on the switch port.
The port must be an NNI type and must be in trunk mode.

[/li]
[li]A VLAN is a logical grouping of switch ports that belong to these:
The same IP subnet
The same broadcast domain

[/li]
[li]Refer to the configuration:
[quote]SwitchX#configure terminal
SwitchX(config)#interface fa0/11
SwitchX(config-if)#switchport mode trunk
SwitchX(config-if)#end[/quote]
VLAN 1 traffic is sent untagged on the fa0/11 trunk port.

[/li]
[li]Refer to the partial configurations:
[quote]!ME3400
!
ip routing
!
vlan 10
vlan 20
interface Fa0/1
switchport access vlan 10
interface Fa0/2
switchport access vlan 20
![/quote]
[quote] interface vlan 10
  ip address 192.168.10.1 255.255.255.0
!
interface vlan 20
  ip address 192.168.20.1 255.255.255.0
![/quote]
Is additional configurations are required to enable inter-VLAN routing for VLANs 10 and 20 on the Cisco ME 3400 switch using the metro IP access image.

[/li]
[li]Refer to the topology diagram in the exhibit.

[img]http://image.free.in.th/z/ij/spng2.gif[/img]

Interface configuration commands on the Cisco ME 3400-1 switch Fa 0/1 interface are required to support the VLANs for Customer A to be trunked across the service provider network:
switchport mode dot1q-tunnel
switchport access vlan 30

[/li]
[li]2002::/16 is IPv6 address block is reserved for 6to4 tunneling.

[/li]
[li]When upgrading a Cisco ASR 1001 Router, to run the router using individual subpackages is the request platform software package expand file bootflash:image-name command required.

[/li]
[li]Cisco 12000 GSR is Cisco router platform supports running either the Cisco IOS or IOS XR operating system.
The CRS-1 platform natively runs the IOS XR operating system. The c12000 platform, originally being an IOS router, can be upgrade to run IOS XR. However, c12000 hardware, including line cards (LC) as well as route processors (RP), must be checked for XR compliance.
TURBOBOOT refers to a fresh boot of the router from ROMMON. TURBOBOOT is required if an IOS router is being converted to IOS XR or as a last resort disaster recovery in the case of CRS-1. If the router is already running an IOS XR image, there is no need to TURBOBOOT the router for an upgrade or downgrade.
A new c12000 platform can be ordered prebaked as an IOS XR router; however, there will always be cases where an IOS running c12000 needs to install IOS XR.

[/li]
B-)