ccna certification exam questions and answers pdf

ccna certification exam questions and answers pdf

Routers in the network must identify all in order to perform appropriate operations Interface eth 0/0 The interface of each router activates RSVP and MPLS TE tunnel support. Network 5.5.5.5 0.0.0.0 area 0 Network 10.1.45.4 0.0.0.0 area 0 *Aug 18 09:06:07.919: SRM : used to control the delivery of LSPs to adjacent routers during the update process. Net 49.0001.0000.0000.0002.00 Traditional TTL operation 10.1.34.4 [MPLS: Label 400 Exp 0] 4 msec 0 msec 4 msec Fspec: ave rate=20000 kbits, burst=1000 bytes, peak rate=20000 kbits History: Ip address 10.1.24.2 255.255.255.0 Version : value is 1 33000 10.1.23.3 Send out from the Fa1/0 port. So, R2 replaces the tag with 300 and then throws it to R3 . Options: (No TOS-capability, DC) LS Type: Router Links The forwarding of IP packets in each hop router is based only on the destination address. Tunnel mpls traffic-eng autoroute announce 1.1.1.0 [115/20] via 10.1.12.1, FastEthernet0/0 Path option 10, type dynamic (Basis for Setup, path weight 20) After calculating the path, you need to reserve resources and distribute labels through RSVP . The RSVP path message is transmitted one hop along the calculated PATH and requests resources and labels. Then R7 will give the response and bring the label back. This tag distribution and resource reservation actions are also performed one by one. In this way,ccna certification exam questions and answers pdf, an LSP is finally established. Ip access-list standard accept-ldp permit 1.1.1.1 DIS send HELLO interval ordinary packet router of 1/3 (default 3.3s ) PHP penultimate jump pop-up mechanism 10.1.12.2 Complete MPLS TE configuration on R1 . Connection TCP: 2.2.2.2.31044 - 1.1.1.1.646 , indicates that the LDP connection is built on TCP 's 1.1.1.1 source port 646 , to the destination 2.2.2.2 of 31044 ports. Because the 2.2.2.2 address is large, it is the initiator. Last update from 10.1.123.2 on FastEthernet0/0, 00:01:32 ago Routing Descriptor Blocks: In order for the protection feature to work properly, you need to enable this feature on both LSRs . If one end does not support this feature, you can configure the feature in one segment and the mpls ldp discovery targeted-hello accept command on the other end to receive target-hello . The configuration of R2 is as follows (the tunnel is not configured temporarily ): Ip router isis *Aug 18 04:37:06.239: SESSION type 7 length 16: PATH If a tunnel1 establish priority than the tunnel2 high hold priority, then tunnel1 be able to seize tunnel2 Last update from 10.1.123.2 on FastEthernet0/0, 00:01:32 ago Routing Descriptor Blocks: Mpls traffic-eng tunnels mpls label range 200 299 IS-IS 10.1.12.2 This TLV by L2 router establishes a virtual link through a backbone network between Remote binding: tsr: 2.2.2.2:0, tag: 200 IDP and DSP can be borrowed from the concept of IP inside. IDP has something like the main network number. DSP has something like subnet number and host IP . Of course, the meaning of this IDP is relatively complicated. See The following figure: Allocation pattern (the Label Allocation) : independent control mode (Independent Control) During the establishment of the adjacency relationship, the neighbors send CSNPs to each other (the CSNP is not sent after the adjacency is established ). *Aug 18 09:06:02.699: version:1 flags:0000 cksum:5878 ttl:255 reserved:0 length:216 R1 goes from R2 and then goes to tunnel . The cost of this path is cost=10+1+1=12 Assuming the bandwidth of the local physical outgoing interface is 100M , the default reservable bandwidth of rsvp is 75% . Here is 75M. It is followed by a second number, which is used to indicate that the device restart needs to set the overload-bit time. After this time, the overload-bit is cleared. Phenomenon observation Fragment number : 0 Outgoing interface IS-IS routers belong to only one specific area Router(config-router)# max-area-address xx RFC 2763 Up Thresholds 15 30 45 60 75 80 85 90 95 96 97 98 99 100 1 10.1.12.2 12 msec 4 msec 4 msec Ip address 5.5.5.5 255.255.255.255 The TLV section contains fields for system characteristics, as shown below: Link state messages are used to propagate link and node information in the area (describe the topology of the local network) As long as the route prefix is ​​learned locally through the IGP , the route prefix is ​​assigned a label ( locally also assigns a POP label to the direct route ) Type block This is 1B , which contains a number of important bits: Router(config)#ip explicit-path name ccietea i L1 *Aug 18 11:26:02.546: 400 *Aug 18 09:06:07.919: Outgoing PathTear: N-SEL 1- byte selector, English: NSAP-Selector is similar to the port in TCP/IP , identifies the process (or service) on the device, and is 00 in NET . Path option 10, type dynamic (Basis for Setup, path weight 3) Let's experiment one by one: BandwidthOverride: disabled LockDown: disabled Verbatim: disabled 10.1.12.2 *Mar 1 00:00:32.639: %BGP-5-ADJCHANGE: neighbor 10.1.24.4 Up Fa0/0 10.1.12.2 3.3.3.3/32 Then, if you are in the tunnel port on R1 , use the following configuration: The local device will actively advertise the generated label mapping message to all LDP neighbors. The label header has a total of 32 bits and contains the following fields: [115/10] via 10.1.123.2, FastEthernet0/0 Mpls traffic-eng tunnels ip rsvp bandwidth On CISCO IOS , I verified the packet authentication and found that domain authentication, IIH message, CSNP , and PSNP do not carry authentication information. 1.0.0.2 Interface is up and sending maximum metric Interface eth 0/0 Multi-zone integrated IS-IS configuration metric Parameters: R1#traceroute 4.4.4.4 Link ID:: 0 !! R2 has two direct links to participate in MPLS TE . This is the first, which is F0/0 . It should be noted that usually the terminal systems in our live network environment, such as PCs , do not use ES-IS because these PCs are running 10.1.34.4 Net 49.0001.0000.0000.0003.00 101 Path maintenance The IP forwarding instance does not consider the available bandwidth and load capacity of the link. It is possible that the metric assigned by the link is not the same as the actual metric . The TLVs used are: The loopback0 address space of all devices is xxxx/32 , and x is the device number. *Aug 18 04:37:06.239: Error Value: 0x5 (No route available toward destination) Link State ID: 2.2.2.2 Advertising Router: 2.2.2.2 LS Seq Number: 8000001F Checksum: 0x580A Length: 60 !! Primary tunnel Mpls traffic-eng tunnels ip rsvp bandwidth Record Route: 10.1.34.3 10.1.13.1 18 State Type 7 length 16: Net 49.0001.0000.0000.0002.00 The label required for traffic in the TE tunnel. R5 configuration is as follows 722 The loopback0 address space of all devices is xxxx/32 , and x is the device number. Expense metric Located inside the ordinary area R1#show isis database State: Oper; Msgs sent/rcvd: 16/16; Downstream Up time: 00:05:38 R2.00-00 Interface tunnel0 10.1.13.3 CSPF ( Constrained Shortest Path First ) SPF algorithm with constraints Mpls traffic-eng reoptimize events link-up For the highest loopback port IP R1#show mpls traffic-eng tunnels PDU DN !! TE metric , the default is equal to the following IGP metric Interface Ethernet0/1 MPLS label SNPA Routing information diffusion in point-to-point links The LSP : R3.02-00 , here marked as non-dummy node 0 , then R3 is a the DIS , and that the LSP , is a dummy node the LSP . Level2 area Tunnel mpls traffic-eng priority 7 7 tunnel mpls traffic-eng bandwidth 20000 Conservative mode : Conservative Retention Fa0/0 R2.00-00 Router ospf 100 0x7056 Signalling: connected Router-id 4.4.4.4 *Aug 18 09:06:07.919: version=0 length in words=10 The L1 router only has the link state database of Level1 in the area , and contains routing information of all L1 routers in the area. Ip address 1.1.1.1 255.255.255.0 ip router isis IS-IS hierarchy Do not elect DIS , use CSNP to trigger database synchronization after the link is established . 4.4.4.0/24 Experimental configuration A very important problem in MPLS networks is the synchronization of LDP and IGP . The so-called synchronization means that both IGP and LDP recognize that a link is the outbound link of the message to be forwarded . For example, in the above figure, all four routers run OSPF and activate LDP . Then on R1 , if it goes to the route 3.3.3.3/32 , the next hop in the routing table is R2 (assuming we adjust the cost ), and at the same time we receive the bundle of 3.3.3.3/32 prefix sent by R2 . The label 401 , then IGP and LDP are synchronized at this time, and R1 can normally use R2 as the next hop to forward MPLS label messages.