cisco certified network associate exam questions

cisco certified network associate exam questions

TCP connection: 3.3.3.3.41954 - 1.1.1.1.646 Ip unnumbered Loopback0 tunnel mode mpls traffic-eng tunnel destination 5.5.5.5 !! set overload-bit The configuration of R2 is modified as follows: Each of our IS generates an LSP , and the first segment of the LSP is numbered 0 . But if my LSP is particularly large, it exceeds the interface. R2 , R3 , R4 , and R5 are MPLS VPN Backbone routers. The Backbone IGP protocol running is OSPF , and the process ID is used. Switched Record Route: 2.2.2.2(200) 4.4.4.4(403) Label (Link ID) Designated Router address: 10.1.23.3 (Link Data) Router Interface address: 10.1.23.2 Number of MTID metrics: 0 We complete the experiment as long as the R2 and R4 configuration domain-password can, Rl is a zero-configuration ( Domain Authentication actually level2 LSP embedded for authentication TLV ). Test 2 : SET-overload-ON-Startup 'bit the wait-for-BGP Two modes: frame mode ; ATM mode ( cell mode ), we mainly study frame mode IS reachability Is a sequence of LSRs that switch a labeled packet through an MPLS network or part of an MPLS network. Tib entry: 3.3.3.3/32, rev 13 Here are some examples of FEC : This will cause the route of R2 to change. The outgoing interface of the route to 5.5.5.5 and 55.55.55.55 becomes e0/1 . So R2 goes to Pop Label Let's look at the picture. If R1 to R6 want to establish a TE tunnel , which is the optimal path, and the bandwidth requirement is 30Mbps , what is the calculation process? First of all, thanks to the flooding of link state information in the zone, " OSPF or IS-IS for MPLS TE extensions ", OSPF Router with ID (1.1.1.1) (Process ID 1) If not manually set metric , the re-release came default metric is 0 , that is, R2 routed the metric is R2 is S0 / 0 port Level-1 metric Mpls traffic-eng tunnels mpls ip Certification Information IGP Id: 1.1.1.1, MPLS TE Id: 1.1.1.1 Router Node id 1 The checksum calculation knows the end of the packet starting from the field after the remaining time-to-live field in the LSP . When the LSP copy is propagated between routers in the network, its checksum field is not modified. Use the lockdown keyword (note that the above configuration is configured in the TE tunnel port). A value of 0 indicates that the maximum number of three area addresses is supported . By default, the value is 0 , and the actual value is in the range of 1-254 . Mpls traffic-eng tunnels mpls label range 400 499 Type-10 Opaque Link Area Link States (Area 0) State: dynamic path option 10 is active NNHop ( Next-Next Hop Router ): Next hop router, next hop of the PLR next hop router My Address: 10.1.12.1 Set-overload-bit on-startup 120 Expense metric 0/0/0 In this way, B receives a label packet with a label value of 22 sent by A , and pops the label to obtain an IP packet, and then forwards it to C , and then C only needs to search and forward the FIB table of the IP packet . 558 RFC1195 ! 0 kbits/sec 201 *Aug 18 04:37:24.735: %LINEPROTO-5-UPDOWN: Line protocol on Interface Tunnel0,cisco certified network associate exam questions, changed state to down Interface fas1/0 R1#show mpls ldp neighbor Ip address 10.1.12.1 255.255.255.0 The local device will actively advertise the generated label mapping message to all LDP neighbors. Mpls ldp discovery targeted-hello accept from accept-ldp Router ospf 1 0x00000026 We see that in the LFIB of R3 , going to the destination of 1.1.1.1 , there are two label paths for load balancing. Next we R1 on shutdown Fa1 / 0 mouth, then R1 on a look: Priority : Priority. The DIS priority of the interface used to elect the DIS in the broadcast LAN . The higher the priority value, the more likely the router becomes a DIS . 4 10.1.45.5 0 msec * 0 msec The agreement was released as RFC1195 . 202 R1#show ip ospf database opaque-area self-originate Show ip route isis Tunnel mpls traffic-eng autoroute announce tunnel mpls traffic-eng priority 7 7 75000 10.1.34.4 [MPLS: Labels 403/505 Exp 0] 0 ​​msec 4 msec 0 msec BoS MPLS TE tunnel 5.5.5.5/32, version 22, epoch 0, cached adjacency 10.1.34.3 Se1/0 RFC 3277 End LSP ID : End LSP ID . Indicates the last LSP ID of the LSP range described in the TLV field . The above output is the opaque-area LSA of type10 flooded by each router in area0 in this environment . You can take a closer look at it, for example, look at R1 itself to generate LSA10 : *Aug 18 09:06:07.919: 1.1.1.1 (Strict IPv4 Prefix, 8 bytes, /32) Type 2 length 48: Next-address 10.1.34.4 All routers run IS-IS Session_Attibute CSPF ( Constrained Shortest Path First ) SPF algorithm with constraints In operational contexts , a tunnel can be removed from one path and palced onto another. Mpls traffic-eng tunnels mpls label range 300 399 Router ospf 1 1800s , and is a fixed value 19 Tag C 1.1.1.0 is directly connected, Loopback0 5.0.0.0/24 is subnetted, 1 subnets Let's start with a brief introduction: Ip cef Priority 0 : 9375000 IS-IS routers belong to only one specific area Since the IP packet is generated on the initial router, the CEF table is searched . With the " show ip cef detail " command, you can see from the output whether the route is pushed into the label. The distribution label is based on The prefix in the CEF table is assigned. Use show isis hostname to view the mapping of host names Explicit Route: 10.1.12.2 10.1.23.2 10.1.23.3 10.1.34.3 OutLabel : FastEthernet0/0, 200 RSVP Signalling Info: IS-Extended R2.01 R1(config-keychain)#exit *Aug 18 04:37:06.243: STYLE type 1 length 8 : My Address: 10.1.12.1 Explicit Route: 10.1.12.2 10.1.23.2 10.1.23.3 10.1.34.3 Next we R3 and R5 activate the forwarding adjacency, then R3 and R5 will be advertised in this region of the Tunnel- ( L in the manner of direct links). Mpls traffic-eng router-id loopback0 mpls traffic-eng area 0 Interface tunnel0 Bw[1]: [115/20] via 10.1.24.2, Serial0/0 *Aug 18 09:06:07.919: version=0, length in words=7 Now we configure MPLS LDP-IGP synchronization on R1 and R2 : Ip explicit-path name R3R4 enable next-address 10.1.23.3 Intermediate system adjacent router 0/0/0 Explicit Route: 10.1.23.3 10.1.34.3 10.1.34.4 4.4.4.4 R1#show mpls ldp discovery detail Mpls traffic-eng tunnels ip rsvp bandwidth Link Link Tunnel mpls traffic-eng path-option 10 dynamic Router-id 2.2.2.2 OSPF version1 was released as RFC1131 in October 1989 . The 1990 Nian 12 Yue has IP routing extensions Integrated IS-IS Tunnel mode mpls traffic-eng tunnel destination 4.4.4.4 75000 In CISCO IOS routers, IOS cannot automatically allocate bandwidth-based link (interface) metrics. Regardless of the bandwidth of the link, the default IS-IS metric for all interfaces is 10 , of course you can modify it. The maximum metric for a full path is 1023 . Of course, the IETF has extended the default metric . Virtual link PSNP Address, see what the next IP address is, and then send the PATH message to the next hop. This behavior continues backwards until the LDP Id: 2.2.2.2:0 // 2.2.2.2 is router-id ; 0 is label gap PHP penultimate jump pop-up mechanism Network 10.1.23.2 0.0.0.0 area 0 Tunnel mode mpls traffic-eng tunnel destination 5.5.5.5 Ip rsvp bandwidth !!tunnel establishment and retention priority ! Mpls ldp igp sync holddown msecs Such as PPP , HDLC Ip explicit R1toR5 *Aug 18 04:37:06.239: Error Code: 24 (Routing Problem) Network 10.1.45.4 0.0.0.0 area 0 mpls traffic-eng router-id loopback0 mpls traffic-eng area 0 The configuration of R2 is as follows (all configurations are omitted from the configuration of interface IP ): VPN tags are distributed by BGP . In any case, LFIB is always used to forward inbound tagged messages. ADV Router LSP Seq Num Downstream active mode : Downstream Unsolicited As a result, the size of the LSPDB is greatly reduced. Note that the above picture is just an abstraction and simulation concept. The ABCD four routers actually have ISIS adjacencies (in IS-IS broadcast). In the network, adjacencies are formed between routers of the same level on the same network segment, including all non- DIS routers. This is different from OSPF . However , after DIS , everyone The resulting LSP volume is reduced. That is to say, although all routers on the IS-IS broadcast network form an adjacency relationship, the synchronization of the LSDB is still guaranteed by the DIS . The LSP stability and reliability has been guaranteed. The operation of the SPF algorithm is naturally faster.