ccna routing and switching exam prep

ccna routing and switching exam prep

55000 10.1.12.2 Tun Sender: 1.1.1.1 LSP ID: 521 ! Interface fas1/0 Ip unnumbered Loopback0 tunnel mode mpls traffic-eng tunnel destination 4.4.4.4 10.1.34.4 [MPLS: Labels 404/505 Exp 0] 0 ​​msec 0 msec 0 msec Area Address: 49.0001 ! Interface eth0 0/0 When using the Explicit method to establish a tunnel , you need to associate an explicit path . 5.5.5.5/32 The final R1 on the show isis database Used to publish a complete link state database on a router , CSNP is used to inform other routers of their own database may be outdated or lost LSP . Continue to show it: Indicates whether the LSP is from L1 router or L2 router . This field is 2bits . 00- not used; 01-level1 ; 10- unused; 11-level2 42000 LDP neighbor discovery 200 Mpls traffic-eng tunnels mpls label range 400 499 *Aug 18 04:37:06.239: Error Value: 0x5 (No route available toward destination) The configuration of R4 is as follows: Domain-password cisco Router ospf 1 Ip router isis Overview Local binding: tag: imp-null Regional information *Aug 18 11:26:02.546: I have already said it above. The final R1 on the show isis database If the highest bit (the leftmost bit) is 0 , the metric type is default metric . If it is 1 , it means the metric is not supported. Record Route: NONE Remarks If there is a loop (usually a problem with the IGP , such as a misconfiguration of the static route), the TTL in the tag header will prevent the tag packet from being forwarded indefinitely. Define source Oper: up The interface will be created. We just need to put the traffic into the tunnel port, there are still a lot of methods, we will continue to introduce in the following content. *Aug 18 09:06:07.919: SENDER_TSPEC type 2 length 36: IS-IS Level-1 Link State Database: Point3 *Aug 18 09:06:07.919: Path MTU: 4294967295 697 LSP Database LSP database *Aug 18 11:31:44.598: IS-IS adjacency and network type The main function of the ES-IS protocol is to provide mapping of NSAP addresses to SNPA addresses for network devices . So we have also defined an explicit null tag to handle the scenario described above. Parameter id=127, flags=0, parameter length=5 0 kbits/sec Network 5.5.5.5 0.0.0.0 area 0 Label 1 router warning label Tag rewrite with Fa0/0, 10.1.34.3, tags imposed: {303} Reservable BW (kbps) Attached-bit Or Tunnel Id Each IP packet forwarded to a router is the same before and after being forwarded through the router. Various bandwidth information 0x00000017 Mpls traffic-eng tunnels mpls label range 200 299 Tunnel mpls traffic-eng path-option 10 dynamic The TLV section contains fields for system characteristics, as shown below: Access-list 100 deny udp any any eq 646 access-list 100 permit ip any any Still this figure, but the configuration of R2 becomes: AutoRoute: disabled LockDown: disabled Loadshare: 0 bw-based auto-bw: disabled ! *Aug 18 04:37:06.239: version=0 length in words=10 LSP TLV field of Level 1 route We see that the Tunnel is up, and R2 goes to the 5.5.5.5 route, the outgoing interface is tunnel , and the TE tunnel is up. Complete sequence number packets ( CSNP ) Complete sequence number packet R5 configuration is as follows Fa0/0 The configuration of R2 is as follows: Config Parameters: IS-IS support for IPv6 Attached 75000 IS-IS supports ISO CLNP and IP environments Tag information from 10.1.15.0/24, shared local tag: 403 Outgoing Label L1 router re-releases external routes into IS-IS Then just fill in the configuration on R2 . I won't go into details here. Ip router isis Run OSPF on the entire network to announce direct connection and loopback interface. Use of OSI IS-IS for Routing in TCP/IP and Dual Environments A list of directly connected IP address prefixes is listed, which is only used in non-pseudo-node LSPs . Static mapping, when the network size is large, the configuration is surprisingly large. The enhanced features of IS-IS are defined in RFC 2763 , among which there is a mapping definition of dynamic host names. RFC 2763 introduces a new TLV , Type 137 , which is included in the LSP sent by the router participating in the dynamic mapping. ! *Aug 18 09:06:07.919: Controlled Load Service break bit=0 service length=0 0 kbits/sec 19 Tunnel mpls traffic-eng path-option 10 explicit name R2R4R5 Focus on the 2.2.2.2/32 entry. The current outgoing label is pop , which is an empty label. R1(config-router)#authentication key-chain test level-1 R1(config-router)# authentication mode md5 level-1 R2.00-00 LSP 302 Router ospf 1 ! *Aug 18 04:37:06.239: min unit=0 bytes, max pkt size=2147483647 bytes By default, the OSPF hold time ( dead-interval ) is MPLS is a forwarding technology based on packet labeling Link Sharing Detail: IS-IS allows the entire domain to be divided into multiple zones, using a two-level hierarchical structure. OSI has established standards for two network protocols for routing: ES-IS and IS-IS : One is a Point-to-Point IS to IS hello PDU . If CSNP is received and it is found that LSPs are lost , the router will retransmit the lost LSP . Tunnel mpls traffic-eng autoroute announce tunnel mpls traffic-eng priority 7 7 Remarks *Aug 18 04:37:06.239: SENDER_TEMPLATE type 7 length 12: Interface Loopback0 Net 49.0001.0000.0000.0001.00 Ip cef If R3-R5 , LDP is run , let R5 send the label packet, R3 receives the label packet, looks at the byte after the label stack, and finds the value is 4 , so it is determined to be an IPv4 packet, so the IPv4 header is The source and destination addresses are taken out for hashing to perform load balancing. Ip address 10.1.34.3 255.255.255.0 If the LSR receives an IP packet, check the FIB table. Assume that the FIB ( CEF table) related entries are output as follows: Then R1 will limit the establishment of targeted session of the peer , is 3.3.3.3 , which is R3 of LDP routerid , in addition, LDP session protection time is 30S , that is to say, 30S If the LDP neighbors yet up, targeted session will fail. Naturally, the protected tag information stored in the LIB is gone. Path calculation TOS 0 Metrics: 1000 !! default tunnel port advertised cost = 1000 L1 router Path option 10, type dynamic (Basis for Setup, path weight 3) Bytes tag switched 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). The configuration of R3 is as follows: Pop Label Filter the inbound label bundles advertised by LDP neighbors. 4.4.4.4/32, version 12, epoch 0, cached adjacency 10.1.12.2 The configuration of R2 is as follows: L1 5 10.1.56.6 4 msec * 4 msec IS-IS adjacency on a point-to-point link *Aug 18 11:26:02.546: 10.1.23.0/24 AutoRoute Device Configuration LDP certification 4.4.4.0/24 Oldtime Circuit Id The configuration of R2 is as follows (all configurations are omitted from the configuration of interface IP ): In general, any router that checks for a corrupted LSP will be corrupted by sending a remaining lifetime to 0 . *Aug 18 09:06:07.919: version=0, length in words=7 When forwarding, if the destination address is present in the area within, the direct use of L1 LSDB routes generated forward packets,ccna routing and switching exam prep, if the destination address is not in the region, the use of this area nearest L1 / L2router as an outlet outside the area network, whereby May cause sub-optimal routing Run IS-IS on the entire network to announce direct connection and loopback interface. The Address Interface IPv6 : type value 232 ( 0xE8 ), which corresponds to the IPv4 in " the IP Interface the Address" TLV , but the original 32 -bit IPv4 address to the 128 -bit IPv6 address. Outgoing tag or VC Can see outbound PATH and inbound RESV messages Fa0/0 LDP Id: 2.2.2.2:0 // 2.2.2.2 is router-id ; 0 is label gap R1(config)#key chain test Remaning timer This configuration is suitable for situations with explicit session endpoints. 2.2.2.0/24 See below for more details. 10.1.34.0/24 75000 Fa0/0 Link ID Tunnel: R1 , R2 , R3 , and R4 are in Transit AS 1234 . The IGP protocol running in the AS is OSPF. Hello data unit: sent periodically to determine whether other ISs are running IS-IS , establish adjacencies, exchange LSPs , and synchronize LSDBs . Route metric is 168, traffic share count is 1 75000 0/0/0 Next Hop Global Pool Sub Pool P2P Links: Multiacces Links: PATH/RESV Mpls traffic-eng tunnels ip rsvp bandwidth Fragment number : 0 20. Then we can use TE tunnel thinking to create two TE tunnels on R1 , as shown below: Interface eth0 0/0 *Aug 18 09:06:07.919: SENDER_TSPEC type 2 length 36: 2.2.2.0 [115/20] via 10.1.123.2, FastEthernet0/0 3.0.0.0/24 is subnetted, 1 subnets Frame-relay map ip 10.1.123.3 201 broadcast frame-relay map clns 201 broadcast R3.02 Interface loopback0 RSVP Signalling Info: Remote binding: tsr: 2.2.2.2:0, tag: 202 tib entry: 10.1.23.0/24, rev 12 ! Mpls traffic-eng tunnels mpls label range 400 499 Use the above command to view the TE metric. Ip address 10.1.12.2 255.255.255.0 R1#show ip cef 4.4.4.0 detail 4.4.4.0/24, epoch 0 R2#sh run | Bytes Label Integrated IS-IS ( IS-IS ) enables the IS-IS protocol to propagate routing information for protocols other than CLNP . Fa0/0 Label or VC Bytes Label Config Parameters: Set-overload-bit Contains information such as the tunnel sender address, LSP ID, etc. Fa0/0 Tunnel mpls traffic-eng record-route 10.1.23.3 Feature overview In this way, R2 will ignore the LDP hello packet received from the R1 on the interface , and then the LDP adjacency between R1-R2 will DOWN after a while. Pop Label Net 49.0001.0000.0000.0001.00 *Aug 18 09:06:07.919: Hop Addr: 10.1.12.1 LIH: 0x20000403 ---------- R4 configuration is as follows Such as PPP , HDLC Time since path change: 10 minutes, 34 seconds Number of LSP IDs (Tun_Instances) used: 521 Router(config-if)#tunnel destination ip-addr Mpls traffic-eng tunnels mpls label range 100 199 We see that on R1 , the outgoing label of the relevant route prefix is untagged . The R1 's routing table temporarily without any change. In this environment now, although R1 still be able to ping through 3.3.3.3 , but in fact has a problem, because it is a direct walk IPv4 packets, rather than the package label. Lan interface MAC address Router isis *Aug 18 09:06:07.919: min unit=0 bytes, max pkt size=2147483647 bytes 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. All interfaces of ospf area0 will automatically activate LDP. 1.0.0.0/24 is subnetted, 1 subnets This bandwidth is reserved for the TE tunnel . If the bandwidth value is not added after the command, the default is 75% of the interface bandwidth. Ip address 2.2.2.2 255.255.255.255 Pop Label Test the transmission process of the data stream, observe the phenomenon The router generates a label locally for each IGP prefix and distributes it to the LDP neighbor. It also receives labels for the specific prefix from other LDP neighbors. The router stores the local label and the remote label (which the LDP neighbor sent to me) in the LIB . Admin: up Oper: up Path: valid Signalling: connected IGP System ID: 2.2.2.2 !! Set overload-bit to suppress external routing Record Route: NONE Fa0/0 Record Route: NONE 204 Tunnel mpls traffic-eng record-route Certification Information IS-IS Level-1 Link State Database: Et0/1 The PATH message is sent to the end of the hop by one hop; the RESV message is sent to the headend router in the opposite direction. Next, look at R3 : R3 configuration is as follows (Note that, Area0 and area1 must activate the MPLS the TE ): RFC1195 !! Change to 33M MTU , then it is possible to first slice and then pass, and then use this slice number to indicate ( 0 is the first segment, 1 bit second segment, and so on), the maximum length of a single LSP is 1492 bytes, the most Can be divided into 255 pieces. IS-IS performs fragmentation when generating LSPs instead of generating large LSPs first , and then fragmenting them at the network layer (for example, IP ), thereby achieving the negative effect of reducing CPU resource waste.