ccna exam tips

ccna exam tips

The password is inserted in Level2 LSP , CSNP , and PSNP . The command is as follows (in the routing process): Each transport layer entity is assigned an NSAP address. The NSAP address is the network layer address of the CLNS packet . It is used to identify the device. It consists of an initial domain part ( IDP ) and a domain-defined part ( DSP ). These two parts are detailed below, let us understand this. R1 has already completed the collection of its own TEDB information, and the calculation process of the tunnel path is completed on R1 . *Aug 18 09:06:07.919: One is the LAN on to Ll Router ( Level-1 to the IS the Hello PDUs the IS LAN ), a method in LAN on to L2 of Router (a to the IS LAN the Hello PDUs the IS Level-2 ) The TLV field of the LSP . Here, in addition to the system ID that contains the neighboring IS , there is a bunch of metrics. 10.1.23.2 1.1.1.1 *Aug 18 09:06:07.919: 10.1.45.5 (Strict IPv4 Prefix, 8 bytes, /32) 0 kbits/sec BandwidthOverride: disabled LockDown: disabled Verbatim: disabled R1#show mpls ldp bindings (View the LIB table of R1 ) 3.3.3.3 Type 2 length 36: ! Min unit = 0 bytes,max pkt size = 1500 bytes R2#show mpls traffic-eng fast-reroute database Mpls traffic-eng tunnels mpls label range 400 499 ! Next-address 10.1.12.2 Take a look at the routing table for R1 : Label Ip cef OutLabel : FastEthernet1/0, implicit-null RSVP Signalling Info: The IETF 's draft-ietf-isis-ipv6-05.txt specifies what IS-IS adds to support IPv6 . It is mainly a newly added two TLVs ( Type-Length-Values ) supporting IPv6 routing information and a new NLPID ( Network Layer Protocol Identifier ). IS-IS is not like RIP and OSPF . These two protocols have separate versions of RIPng and OSPFv3 support IPv6 . *Aug 18 09:06:07.919: ERROR_SPEC type 1 length 12: Set-overload-bit suppress interlevel redistribute connected level-1 10.1.12.2 Session hold time: 180 sec; keep alive interval: 60 sec Discovery hello: holdtime: 15 sec; interval: 5 sec Discovery targeted hello: holdtime: 90 sec; interval: 10 sec Intermediate system adjacent router (Tunnel0) Destination: 4.4.4.4 Although R5 and R6 can learn each other's routes, they cannot communicate with each other because routing black holes appear on R2 and R3 . The solution is to use MPLS , we turn the Core into an MPLS domain: The L1 and L2 IIH PDUs on the LAN are sent to different multicast MAC addresses: L1 is 0180-C200-0014 , L2 is Net 49.0001.0000.0000.0001.00 1.1.1.1 Priority 0 : 9375000 Network 10.1.34.3 0.0.0.0 area 0 mpls traffic-eng router-id loopback0 mpls traffic-eng area 0 Election order of DIS We see the above output, R1 , R2 , R3 all generate LSP , and the asterisk entry is issued by R1 itself. In addition, there is a special IS-IS uses a simple two-layer structure. The IDP and HODSP are combined to be used as the area ID of the Layer 2 route , and the remaining system IDs are used as the first layer of routing. 10.1.12.2 [MPLS: Label 200 Exp 0] 4 msec 0 msec 0 msec The configuration of R4 is as follows: *Aug 18 04:37:06.239: SESSION type 7 length 16: Mpls ip Mpls traffic-eng tunnels ip rsvp bandwidth The forwarding behavior of such IP packets may cause link transitions in some networks, while other links have a low probability of use. Note that at this time, although the LDP adjacency between R1 and R2 has been broken, in principle, LDP does not adjacency, in the case of synchronizing, Just throw the next hop of the traffic that meets the conditions to the tunnel interface. Copy this value. Inter-area IP routing changes; Modify the ldp hello message sending interval, the default 5S L1/L2 router re-releases external routes into IS-IS ( to level-1-2 ) Its ingress and exgress LSRs Tunnel mpls traffic-eng forwarding-adjacency 10.1.12.2 Set-overload-bit on-startup 120 i L2 EXP 75000 Bw[7]: Mpls ldp session protection for 1 duration 30 The fields of the same background color described above are all corresponding. O 0 kbits/sec Oper: up Two processes: neighbor discovery process, session establishment process 10.1.12.0/24 RSVP Path Info: HELLO message OutLabel : Ethernet0/0, 204 RSVP Signalling Info: Router ospf 1 No frame-relay inverse-arp Duration refers to the time required to obtain continuous protection (based on the target LDP session ) after the LDP link adjacency is DOWN . The default is permanent. In this way , we can exchange visits between 5.5.5.5 and 6.6.6.6 , on R6 . Ip address 10.1.45.4 255.255.255.0 Ip cef With PHP's penultimate hop pop-up mechanism, C allocates POP labels for local direct-connected prefixes and advertises them to other LDP neighbors. Tunnel mpls traffic-eng path-option 10 dynamic *Aug 18 09:06:07.919: 10.1.12.2 (Strict IPv4 Prefix, 8 bytes, /32) Path option 10, type dynamic (Basis for Setup, path weight 3 ) LSP midpoint frr information: LSP identifier IS-IS is IIH Overview We went to traceroute on R1 6.6.6.6 R1#traceroute 6.6.6.6 LDP discovery sources: 569 Version/ Protocol ID extension: Value is 1 Can form adjacencies with other L2 (or L1/L2 ) routers ! Oldtime Circuit Id Route summary example 2 on the L2 router Network 10.1.34.3 0.0.0.0 area 0 Upon receipt of this PATH message, the tail router will return a RESV (reserved) message along the same path used by the PATH message, except that the direction is reversed. The RESV message contains the label that RSVP assigns to the tunnel . *Aug 18 09:06:02.699: Tun Dest: 5.5.5.5 Tun ID: 0 Ext Tun ID: 1.1.1.1 Cross-region TE Tunnel ( OSPF ) Experimental configuration Mpls traffic-eng tunnels ip rsvp bandwidth Router(config-if)#tunnel mpls traffic-eng path-option x {dynamic | explicit {name path-name | RSVP extension to LSP tunnel If the MPLS payload is an IPv4 or IPv6 packet, CISCO IOS is used in a destination-based load balancing environment. R1.00-00 Ip explicit-path name R2R4R5 enable next-address 10.1.12.2 State TE with Layer3 Mpls traffic-eng tunnels ip rsvp bandwidth *Aug 18 09:06:07.919: Token bucket fragment (service_id=1, length=6 words Name: R1_t0 Status: IS-Extended R2.01 Mpls traffic-eng tunnels ip rsvp bandwidth LSP link state data unit !! 10.1.23.2 is also unchanged ! Label Mpls traffic-eng tunnels ip rsvp bandwidth OSPF is LSADB Collect IP routing information obtained through other routing protocols IGP Neighbor: ID 10.1.23.2 OSPF is encapsulated in an IP packet with the protocol number of 89. MPLS TE configuration and experiment Next, R1 calculates another alternative path to R7 through the existing information : R1-R2-R4-R5-R7 , this path passes CSPF Bytes tag CEF 's hash algorithm to select the battle interface. Note that if there is an IP (unlabeled) path and a labeled path has the same metric, only the labeled path is used for packet forwarding. This is because in some cases, traffic that passes through an unlabeled path cannot reach its destination. For example , on a P router in an MPLS VPN environment . So far, the basic configuration has been completed. Now let 's create a TE Tunnel on R2 and R5 : Router-id 3.3.3.3 Affinity: 0x00000000 After the configuration is complete, the level 2 LSP sent by R2 will carry the cipher text authentication TLV information (the level 1 LSP is not carried). If this configuration is maintained, we will find that R2 can only learn the R1 release. Routing, this is because level1 LSPs are not authenticated. After completing this experiment, R3 and R4 complete the configuration. Router isis ! 19 !! OSPF cost of the interface DIS no backup DIS , DIS can be preempted, DIS to 3 transmission times frequency Hello PDU Prefix 104 13 i L1 10.1.34.0 [115/20] via 10.1.123.3,ccna exam tips, FastEthernet0/0 C 10.1.123.0 is directly connected, FastEthernet0/0 i* L1 0.0.0.0/0 [115/10] via 10.1.123.3, FastEthernet0/0 Is-type level-1 metric-style wide The first label is applied on the ingress LSR and the label belongs to one LSP. The path of the packet through the MPLS network is bound to that one LSP. All that changes is that the top label in the label stack is swapped at each hop The ingress LSR imposes one or more labels on the packet. The intermediate LSRs swap the top label (the incoming label) of the received labeled packet with another label (the outgoing label) and the transmit the packet on the outgoing link. The egress LSR Of the LSP strips off the labels of this LSP and forwards the packet.