how many questions are there in ccna exam

how many questions are there in ccna exam

Router(config-router)#mpls traffic-eng area x Ip address 10.1.23.2 255.255.255.0 L1\L2 router will inject this external route in Level1 area and Bacbbone. Local tag Network 10.1.23.2 0.0.0.0 area 0 All Layer 2 routers must have a unique system ID within the domain ! 0/0/1 Pop tag Attributes are explicitly assigned to the TE tunnel through administration action. A router can have up to 254 th Area ID . Of course, generally one router belongs to one area, and the situation of multiple areas may be used for merging, splitting or changing of areas (see below). IGP System ID: 2.2.2.2 *Aug 18 11:26:02.546: ! Pop tag Router-id 4.4.4.4 75000 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 . Interface based : Per-Interface Mpls traffic-eng router-id loopback0 mpls traffic-eng area 0 Router alarm tag For the highest loopback port IP i L2 2.2.2.0 [115/20] via 10.1.24.2, Serial0/0 Now let no shutdown R1 of Fa1 / 0 mouth, then R1 and R3 open the LDP session protection. It can be seen that we allocated 33M bandwidth for the tunnel with priority 6. The total reserved bandwidth of the original interface is 75M , and it is divided into 33M , so there is 42M . We can also see because we have modified the priority. The reservable bandwidth of the tunnel of level 6 is therefore lower, and the reserved bandwidth is also changed. Mpls traffic-eng tunnels ip rsvp bandwidth *Aug 18 09:06:07.919: Path Latency (microseconds):0 10.1.23.0/24 Signalling: connected ! Keep priority RFC 3787 In order to ensure the simplicity of the experimental environment first, I will ignore the existence of the R4 and R4 direct links. When you don't exist,how many questions are there in ccna exam, you will be there. The configuration of R4 is as follows: Network 10.1.45.4 0.0.0.0 area 1 FastEthernet0/0, Src IP addr: 10.1.12.2 Addresses bound to peer LDP Ident: Type escape sequence to abort. Tracing the route to 6.6.6.6 R3.00-00 supporting agreement Untagged Interface loopback0 C 1.1.1.0 is directly connected, Loopback0 2.0.0.0/24 is subnetted, 1 subnets Type 2 length 36: Interface fast 0/0 Or Tunnel Id 10.1.34.4 Interface Ethernet0/0 Basic Experiment 1 ( OSPF ) Verify that you receive the LDP Hello from the other party. 906 R4.00-00 Bytes Label LSP Seq Num Tunnel priority The configuration of R2 is as follows (all configurations are omitted from the configuration of interface IP ): Circuit type : 01 means L1 router, 10 means L2 router, 11 means L1/2 router The L1 router only forms an adjacency with the L1 router (or L1/L2 router ) in this area. Device Configuration Reservable Global Pool BW: 75000 kbits/sec Both data packets have the same format and each carry a collection of LSP summary information. The difference is that the CSNP carries summary information of all known LSPs in the link state database of the router , and the PSNP carries one of the subsets. To distinguish Level-1 , Level-2 link state database, the router generates Ll , L2 of independent SNP packets. 1.1.1.1/32 LSRs maintain only one LDPsession for each label space Config Parameters: Label 0 explicit null label TE can provide a solution to avoid link overload by controlling traffic or partial traffic. Let's make a comparison: Level2 area Link State ID: 2.2.2.2 Advertising Router: 2.2.2.2 LS Seq Number: 8000001F Checksum: 0x580A Length: 60 Ip address 4.4.4.4 255.255.255.255 ! LSP Seq Num ! *Aug 18 11:31:44.598: 10.1.23.3 lab environment *Aug 18 11:31:44.598: LSP Seq Num Network 10.1.12.2 0.0.0.0 area 0 Signalling: connected AutoRoute: disabled LockDown: disabled Loadshare: 20000 bw-based Solution: Establish a targeted LDP neighbor relationship between R2 and R4 Tunnel mpls traffic-eng priority 6 6 Activate the MPLS TE extension for each router's OSPF and manually set the RouterID for MPLS TE . Reference book 558 FastEthernet0/0, Src IP addr: 10.1.12.2 Addresses bound to peer LDP Ident: LS age: 29 Exist in the message OSPF and ISIS also have mechanisms for periodic flooding Mpls traffic-eng router-id loopback0 mpls traffic-eng area 0 ! Signalling: connected State: Oper; Msgs sent/rcvd: 13/13; Downstream Up time: 00:04:05 Holdtime Type 1 length 8 : Only when a neighbor solicitation label mapping message to the local strip prefix , local will announce the label mapping messages to neighbors MPLS TE information distribution Interface Tunnel0 *Aug 18 11:31:44.598: Controlled Load Service break bit=0 service length=0 Verify that you receive the LDP Hello from the other party. R1.00-00 ( ... omit... ) 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 ) R3.00-00 Each ES belongs to a specific area, when the ES finds the nearest IS by listening to the HELLO ( ISH ) grouping of the intermediate system . Outgoing interface 10.0.0.0/24 is subnetted, 4 subnets IS-IS Level-1 LSP R1.00-00 Let's take a look at the routing table for R1 : 101 10.1.34.3 A router can have up to 254 th Area ID . Of course, generally one router belongs to one area, and the situation of multiple areas may be used for merging, splitting or changing of areas (see below). i ia 10.1.24.0 [115/148] via 10.1.123.2, FastEthernet0/0 i ia 10.1.45.0 [115/158] via 10.1.123.2, FastEthernet0/0 i ia 10.1.34.0 [115/158] via 10.1.123.2 , FastEthernet0/0 C 10.1.123.0 is directly connected, FastEthernet0/0 LSP Tunnel R1_t0 is signalled, connection is up InLabel : FastEthernet0/0, 400 R2# show ip route Expense metric is optional. The transmission cost of the link is not supported. Local binding: tag: 101 IS-IS packet format ISIS default flooding period is 15 minutes by lsp-refresh-interval Review Tunnel: Local binding: tag: 104 Mpls ldp router-id loopback0 mpls label range 200 299 interface fast0/0 75000 Free mode : Liberal Retention Label 0x26DC (Link Data) Router Interface address: 0.0.0.13 Number of MTID metrics: 0 ! Pop tag Experimental phenomena Remote binding: tsr: 2.2.2.2:0, tag: imp-null 0/0/0 In fact, this is a metric trick, but when we are thinking about it, remember to take the virtual path of the tunnel into consideration. In R1, this L1 router attempts to perform route summarization. The result is a failure. This is similar to OSPF . Routers in the area cannot be routed. Because we want to flood the LSP , the routers in the area must know the area. For details of the topology, if the L1 router is allowed to perform route summarization, does it lose the nature of the link state routing protocol? 3.3.3.0 [115/20] via 10.1.123.3, FastEthernet0/0 10.0.0.0/24 is subnetted, 3 subnets R1#show mpls traffic-eng tunnels Broadcast network Reservable Bandwidth[3]: *Aug 18 09:06:07.919: SESSION_ATTRIBUTE type 7 length 16: PLR ( Point of local repair ): Local repair point, this is the head end of the backup tunnel Ip router isis interface Serial0/0 <0x0-0xFFFFFFFF> Attribute flags Or Tunnel Id Use of OSI IS-IS for Routing in TCP/IP and Dual Environments TE metric is a parameter used to build a TE topology that is completely different from the IP topology (although by default it is equal to IGP metric ) Configure MPLS TE tunnel on R1 . Then apply the ACL on R2 , connect to the interface of R1 , in the direction DR Pop tag Network 10.1.23.2 0.0.0.0 area 0 mpls traffic-eng router-id loopback0 mpls traffic-eng area 0 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. Interface tunnel0 Network 4.4.4.4 0.0.0.0 area 0 1230 Advertising Router: 1.1.1.1 LS Seq Number: 80000001 3 100 It was dismantled and then continued to be removed. Tunnel mpls traffic-eng record-route 2.2.2.0/24 Interface eth0 1/0 However, there may be such a problem that the LDP connection between R1 and R2 is broken for some reason, but between R1 and R2 . *Aug 18 04:37:06.239: Path MTU: 1500 *Aug 18 09:06:02.699: SESSION_ATTRIBUTE type 7 length 16: ! Mpls traffic-eng tunnels ip rsvp bandwidth UP 28 Regional association. The L1/L2 router sets this field in the L1 LSP it generates to notify the L1 routers in the same area to connect themselves to other areas. Usually, the L2 backbone area is connected. When the router in the L1 area receives the L1 LSP from which the ATT bit sent by the L1/2 router is set , it creates a default route to the L1/2 router so that data can be routed to other areas. Although the ATT bit is defined in both the L1 LSP and the L2 LSP , it will only be set in the L1 LSP , and only the L1/2 router will set this field.