cisco final exam

cisco final exam

RSVP extension for LSP tunnel : Forwarding tagged messages R2.00-00 LSP link state data unit In this way, R1 sends data to 3.3.3.3 and sends it directly in the form of IPv4 packets. This seems to be no problem in this topology, and it can pass, but there may be problems in the MPLS VPN environment. Because packets are transmitted in the MPLS VPN Backbone , they are often tagged. Then shut down the e0/1 port of R2 : Type : 0x8848 (Multicast) The upper layer carries MPLS , looking for LFIB My Address: 10.1.23.2 Explicit Route: 10.1.12.2 10.1.23.2 10.1.23.3 10.1.34.4* The IGP will advertise the link with normal IGP metrics. At this time, the traffic that traverses this interface is the traffic for label switching. Basically, if the LDP session is not established, OSPF will not establish adjacencies on this link, and HELLO will not be sent at all (of course, there is a basic word here, that is, there are two cases) . ! *Aug 18 09:06:07.919: HOP type 1 length 12: InLabel : - Interface eth 0/1 Interface eth0/0 RFC1195 75000 Note that, at the moment if desired by modifying the tunnel interface ip ospf cost so as to adjust the route cost , which for autoroute be calculated characteristics associated tunnel routing interface is not valid, use the tunnel mpls traffic-eng autoroute metric commands to configure. Initialization message Support tag distribution in DoD ( Downstream-on-Demand ) mode Interface eth 0/0 Interface fa0/0 mpls ip Ip address 10.1.56.6 255.255.255.0 *Aug 18 04:37:06.239: Token bucket fragment (service_id=1, length=6 words parameter id=127, flags=0, parameter length=5 ! CSPF calculates the path My Address: 10.1.12.1 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 ) Tunnel mpls traffic-eng autoroute metric absolute resolution if the configuration of R2 is changed to: Circuit type : 01 means L1 router, 10 means L2 router, 11 means L1/2 router System Id Router isis Tunnel mpls traffic-eng priority 7 7 tunnel mpls traffic-eng bandwidth 20000 ISO 9542 *Aug 18 04:37:06.239: Error Node: 10.1.12.2 Remote binding: tsr: 2.2.2.2:0, tag: imp-null Router ospf 1 Ip vrf forwarding VPN-A The configuration of R1 is as follows: Ip rsvp bandwidth Experimental phenomena 0 kbits/sec Network 10.1.23.2 0.0.0.0 area 0 mpls traffic-eng router-id loopback0 mpls traffic-eng area 0 SNPA is equivalent to the Layer 2 address of NSAP or NET . neighbor is a neighbor of the LDP routerID accept acl to match the prefix Label 1096 R1#show isis da R3.02-00 detail 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 State: Oper; Msgs sent/rcvd: 16/16; Downstream Up time: 00:05:38 R4.00-00 neighbor is a neighbor of the LDP routerID accept acl to match the prefix 12 0/0/0 Then from the tunnel0 port, cost=1+1=2 , better, so the routing table of R2 changes: Then show it: R1(config)#router isis Then you need the top-level tag, which looks at the next hop. The next hop is 5.5.5.5 , so be sure to find the 5.5.5.5 tag. As we have seen from the routing table, at this point R2 goes to 5.5.5.5 and actually enters the TE tunnel , then: // Prerequisites for binding a label to a route prefix locally Also called a pseudonode, it is a virtual router in a broadcast multi-access network, created by DIS. Generate a default route to this device as the egress route by ATT bit with its nearest L1/L2 router The work of RSVP continues to work based on the sequence of this IP address. Interface Serial0/0 OSPF 's LSA MPLS LDP-IGP synchronization configuration Interface eth0 1/0 The database is also calculated by the CSPF algorithm, and the result is the path of the tunnel — a sequence of IP addresses. Record Route ( RRO ) Interface tunnel0 So now, we will change the loopback port address of R2 to 2.2.2.2/24 and change it to /24 to see what happens. Event caused reoptimize Router ospf 1 1230 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. View message Router-id 2.2.2.2 IS-IS adjacency and network type Interface eth 0/1 Reservable Bandwidth[0]: The PATH message is delivered from the headend router to the following router, then the next hop router will remove its own IP from the ERO . [1]: 75000 kbits/sec So using this feature (an IS-IS process to configure multiple NET addresses), you can achieve: 0 kbits/sec *Aug 18 09:06:07.919: average rate=250000 bytes/sec, burst depth=1000 bytes 2.2.2.2 is directly connected, Loopback0 5.5.5.5 [110/31] via 5.5.5.5, 00:00:01, Tunnel0 10.1.12.0/24 is directly connected, Ethernet0/0 10.1.23.0/24 is directly connected, Ethernet0 /1 *Aug 18 09:06:07.919: min unit=0 bytes, max pkt size=2147483647 bytes 0/0/0 *Aug 18 09:06:07.919: Controlled Load Service break bit=0 service length=0 Router bgp 123 Mpls ldp router-id loopback0 FastEthernet0/0, Src IP addr: 10.1.12.2 Addresses bound to peer LDP Ident: Interface eth 0/0 Message Every downstream neighbor 30S sending RESV message ! Address-family ipv4 vrf VPN-A no synchronization How to view opaque LSA-10 on CISOC IOS router ? Mpls traffic-eng router-id loopback0 mpls traffic-eng area 0 4.4.4.4/32, version 12, epoch 0, cached adjacency 10.1.12.2 InLabel : - Mpls traffic-eng tunnels mpls label range 400 499 Both are link state routing protocols, which require routers in the area to exchange link state information, and link state information is collected in the link state database. Et0/1 Wait for the message to view the adjacency. Next, the DIS election process begins . 1/0/0 AutoRoute basic configuration *Aug 18 04:37:06.239: Incoming PathError: !!R2 sends a patherror message to R1 *Aug 18 04:37:06.243: Tun Sender: 1.1.1.1, LSP ID: 20 Mainly used to replace type 2 TLVs to provide larger metrics. In addition, it also supports IS-IS based MPLS TE Router-id 4.4.4.4 !! Use strict next hop directly in this area The label can be ejected on the (the penultimate hop). C only needs to find the FIB table to forward the received IP packet. i L2 For certification IGP Neighbor: ID 10.1.12.2 10.1.23.0/24 The unit is Bytes , multiplied by 8 is 100Mbps The ACL filters out LDP packets. This prevents LDP adjacency between R1 and R4 from being established. Let's observe the phenomenon. Prefix Remote binding: tsr: 2.2.2.2:0, tag: 202 tib entry: 10.1.23.0/24, rev 12 Interface Ethernet0/0 The establishment of an OSPF adjacency involves a more complex process. Maximum reservable bandwidth : 9375000 Number of Priority : 8 Local A0/0 ADSPEC Seq# Checksum Opaque ID !! configured for the device net address, a plurality of, up default . 3 th Headend frr information: Protected tunnel Network 10.1.23.2 0.0.0.0 area 0 Each priority corresponds to an available bandwidth supporting agreement Test . 5 : SET 'bit-overload-the suppress interlevel Tspec: ave rate=60000 kbits, burst=1000 bytes, peak rate=60000 kbits RSVP Resv Info: Mpls ldp session protection for 1 duration 30 Network 55.55.55.55 area 0 General Parameters break bit=0 service length=8 ! Ip address 2.2.2.2 255.255.255.255 Reservable BW (kbps) Equivalent load balancing in CEF Fa0/0 Network 10.1.34.3 0.0.0.0 area 0 lab environment Support tag distribution in DoD ( Downstream-on-Demand ) mode [3]: 75000 kbits/sec Router-id 5.5.5.5 Ordered control mode : Odered Control ADSPEC R3.00-00 PSNP 132 Device Internet segment 10.1.xy.0 / 24 , where xy is the device number, X small y large IS-IS 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. Consider in detail the details of the adjacency relationship establishment process: The RESVTear message is similar to the RESV except that it is sent when the tail router responds to the received PathTear message. Reserved bandwidth changes (significant changes) *Mar 1 00:00:32.759: ISIS-Upd: Important fields changed Area-password cisco Session_Attibute The PATH message carries a label request object, which is hopped and hopped from the tunnel first-end router to the tail router. The configuration of R4 is as follows: TE with Layer3 Ip unnumbered Loopback0 tunnel mode mpls traffic-eng Mpls traffic-eng tunnels mpls label range 100 199 R2 (config-router)#authentication key-chain test level-2 R2 (config-router)#authentication mode md5 level-2 Priority 6 : 9375000 Then configure it on R1 : Note that at this moment, 2.2.2.0/24 will not be learned on R4 . This external route is completely suppressed on R2 . Src 1.1.1.1, Dst 4.4.4.4, Tun_Id 0, Tun_Instance 163 RSVP Path Info: Router isis Interface eth 0/0 Explicit_route DIS , initially composed of the local SystemID + unique local circuit ID . The router starts to listen to ESH , ISH , IIH at the same time . After receiving the label from the tail router, the penultimate hop router uses the label as the outbound label of the TE tunnel , and assigns a label to the tunnel and places the label in the label object in the RESV message. Send it to its own upstream router. The interface of each router activates RSVP and MPLS TE tunnel support. R1#show ip ospf database Tunnel destination 4.4.4.4 tunnel mode mpls traffic-eng Mpls traffic-eng tunnels mpls label range 200 299 Fa0/0 The IS-IS area defined in ISO 10589 is the stub area. Attached defines four metric types. CISCO IOS only supports the default metric . R2#show ip route Mpls traffic-eng router-id loopback0 mpls traffic-eng area 0 R2-PE1#show mpls forwarding-table detail Each IP packet forwarded to a router is the same before and after being forwarded through the router. Frame-relay map ip 10.1.123.1 301 broadcast 1.1.1.1 My Address: 10.1.45.4 Shared-Explicit (SE) FLOWSPEC PSNP (partial serial number PDU ) Mpls traffic-eng tunnels mpls label range 400 499 2.2.2.2 10.1.23.0 That is , the direct link of R2-R3 is imported into 49.0001 , but the default route generated by R3 does not come together. Router ospf 1 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 The LSP carries the TLV for authentication. 3.3.3.3 [110/65537] via 10.1.12.2, 00:00:47, FastEthernet0/0 1.0.0.0/24 is subnetted, 1 subnets R1#traceroute 4.4.4.4 End host. For example , the ISO CLNP workstation searched by the ES-IS protocol . Outgoing Configure this hidden command on the penultimate hop router (that is, R2 in the figure above ): Pop tag CSPF maximum arbitration LFIB label forwarding information base *Aug 18 09:06:07.919: 5.5.5.5 (Strict IPv4 Prefix, 8 bytes, /32) Reservable Bandwidth[0]: The configuration of R6 is as follows: R1.00-00 Detailed information By default, summaries go into Level 2 if no routing level option is indicated. For this to work, adjacent LSRs must agree on which label to use for each IGP prefix., and each intermediate LSR must be able to figure out with which outgoing label the incoming label should be swapped !! Re-release the local direct loopback 2.2.2.0/24 to level1 Mpls traffic-eng router-id Loopback0 mpls traffic-eng area 0 Reservable Bandwidth[4]: Ip cef * 10.1.123.2, from 2.2.2.2, via FastEthernet0/0 Switched Experimental configuration Reservable Bandwidth[6]: NSAP can be understood as something like an IP+ port number. *Mar 1 00:00:32.783: ISIS-Upd: Sending L1 LSP 0000.0000.0002.00-00, seq 37, ht 1199 on Mpls traffic-eng router-id loopback0 mpls traffic-eng area 0 Point-to-point link 10.1.12.2 Each IP packet forwarded to a router is the same before and after being forwarded through the router. LDP discovery sources: Configuration example 1 : Manual re-optimization Moreover, since the default duration is indefinite, these entries will remain. Of course, if you modify the configuration on R1 : Router ospf 1 My Address: 10.1.12.1 Three-way handshake mechanism: Interface fas1/0 Fa0/0 Then you need the top-level tag, which looks at the next hop. The next hop is 5.5.5.5 , so be sure to find the 5.5.5.5 tag. As we have seen from the routing table, at this point R2 goes to 5.5.5.5 and actually enters the TE tunnel , then: 6 Activate LDP on all devices. To facilitate observation, specify the label range for each device . For example , the label range of R1 is 100. Router isis Impact of route summarization on MPLS The CLNS address is required even if it only provides routing for IP . EXP Label 1 router warning label R1#show mpls forwarding-table (this is the LFIB table of R1 ) Understand the forwarding process of data in the MPLS domain SRM ( Send Routing Message ): Send routing information message L2 rouer redistributes external routes into IS-IS !! Change to 33M Prefix Establishment of LIB and LFIB tables RFC 3786 *Aug 18 11:31:44.598: AutoRoute: disabled LockDown: disabled Loadshare: 20000 bw-based auto-bw: disabled First of all, these three commands all work on the route obtained by the route calculated by the TE tunnel with the autoroute feature enabled . The above command changes the cost of the tunnel interface itself . For IP applications , 1 byte defines AFI in the NSAP address , at least 2 bytes defines the actual area information, 6 bytes defines the system ID and Ip address 1.1.1.1 255.255.255.255 i L1 10.1.34.0 [115/20] via 10.1.123.3, 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 State: explicit path option 10 is active Mpls traffic-eng tunnels ip rsvp bandwidth Note: LDP or TDP only generates labels for routing entries of the IGP protocol, and does not generate labels for BGP routing entries. Holdtimer : If the adjacency relationship is not established, the receiving router creates an adjacency relationship and identifies the adjacency type ( L1 , L2 ), and sets it to the initial state until the subsequent hello packet is confirmed to confirm the adjacency. Note: a FEC can contain multiple streams, but not a stream of a FEC , such as looking at a host Sina website, which is a stream and looking at Sina's video, which in turn is a stream, the two streams When Sina sends to a remote host, the path should be the same, so one FEC has multiple streams, but each stream does not belong to a separate FEC. *Aug 18 09:06:07.919: SENDER_TEMPLATE type 7 length 12: Used in two cases: DIS periodically multicasts every 10s ; the link is just built up in the point-to-point chain. 10.1.45.5* IS-IS link type Outgoing DBD Then from the tunnel0 port, cost=1+1=2 , better, so the routing table of R2 changes: 105 RFC 2973 Reservable Bandwidth[3]: IGP metric: 1 UP Ip cef The forwarding of IP packets in each hop router is based only on the destination address. For example, R1 . 01 - 00, where R1 is SystemID (this is the system ID based on the host name ), 01 is the PseudonodeID pseudo node ID , and if it is sent by the pseudo node, it is non- 00 , 00 is the fragment number. IS-IS Level-1 LSP R3.02-00 Source-based routing can be used here. This LSP is called an MPLS TE tunnel. It is one-way. And the configuration of the tunnel only needs to be performed on the headend LSR . LAN Priority: 64 Format: Phase V Untag : Pops up all the tags and then forwards them according to the next hop (find FIB table). There are three reasons for the occurrence of untag : !!tunnel establishment and retention priority 75000 Configure on the physical interface: CLNP is similar to the IP protocol except that it serves the ISO transport layer. IS-IS , ES-IS , and CLNP are network layer protocols that are encapsulated directly in the data link layer frame. Compared with the OSPF packet in TCP/IP , it is hidden behind the IP header. The encapsulation efficiency of the former protocol packet is higher. Bytes tag FRR intf/label R3.02-00 *Aug 18 11:26:02.546: Interface eth0/1 Since we have configured link protection on R2 to protect the link between R2-R4 , when the E0/1 port of R2 is shut down , the path error message sent by R2 to R1 indicates that R1 does not need to be removed. Drop the tunnel . So R1 of the tunnel will not be removed. Tunnel mode mpls traffic-eng Now let 's take the traffic going to 4.4.4.4 on the R1 to the tunnel , using one of the simplest methods: static routing. Periodically send CSNPs every 10S in the broadcast subnet to flood LSPs Network 2.2.2.2 0.0.0.0 area0 MPLS relies on IP routing and CEF switching System ID 6 -byte system ID , ES or IS identifier, similar to OSPF 's Router ID , each device has a system ID , and the IP network, each interface has an IP , which is the difference between one of . Note: The SystemID must be unique across the entire Area and trunk ( Level2 ). 10.1.12.2 ! Test 2 : SET-overload-ON-Startup 'bit the wait-for-BGP Time since created: 5 hours, 38 minutes About flooding Mpls traffic-eng router-id loopback0 mpls traffic-eng area 0 Turn off TTL propagation *Aug 18 09:06:02.699: 10.1.24.2 (Strict IPv4 Prefix, 8 bytes, /32) R5 configuration is as follows 3.3.3.3/32 Redistribute ospf 1 vrf VPN-A match internal external 1 external 2 It can be seen that ES-IS plays a role in the CLNS network environment as if the ICMP , ARP and DHCP protocols in the IP network work together. Ip cef Mpls traffic-eng tunnels ip rsvp bandwidth Current LSP: ! The TCP/IP protocol stack, similar to ES-IS , is done by ARP , ICMP , and DHCP protocols in the TCP/IP stack . NSAP i ia 10.1.24.0 [115/148] via 10.1.123.2, FastEthernet0/0 TCP connection: 3.3.3.3.33664 - 1.1.1.1.646 FILTER_SPEC The process of exchanging LSPs by routers in an area is called flooding . The LSPs received from neighboring routers in the area are stored in the local router. Link state Protocol Data Unit Link State Data Unit ERROR_SPEC After the basic configuration is completed, since R2 and R3 are L1\L2 routers , for both of them, they will advertise themselves to the local level1 area as a way to go out , by setting ATT in the LSP generated by themselves . we R1 point of view isis database has been able to see out. R1#show isis database i*L1 0.0.0.0/0 [115/10] via 10.1.123.3, FastEthernet0/0 *Aug 18 11:31:44.598: 0xE1E2 Metric , the tunnel 's Metric (for OSPF for the tunnel mouth Default cost = 1000 ) will link status information together with the notice to other neighbors, and also affects other routers routing. R1#sh mpls traffic-eng topology 1.1.1.1 (1.1.1.1 is a local router ) 18 When the tail router receives the label request object, it will assign a label to the tunnel LSP and pass the label. IS-IS Level-1 LSP R3.02-00 Router(config)#tunnel mpls traffic-eng path-selection metric ? igp use IGP metric Fa0/0 Shutdown off R2 in e0 / 1 port in R1 crawl debug information lab environment Ip explicit-path name R2R4 enable next-address 10.1.12.2 Reservable Bandwidth[2]: *Aug 18 04:37:06.243: version:1 flags:0000 cksum:FFAA ttl:255 reserved:0 length:92 1 10.1.12.2 12 msec 4 msec 4 msec LSP Tunnel R1_t0 is signalled, connection is up 1800s , and is a fixed value Is an extended form of type 2 TLV The loopback0 address space of all devices is xxxx/32 , and x is the device number. [115/30] via 10.1.24.2, Serial0/0 2.0.0.0/24 is subnetted, 1 subnets 300 Implicit empty label Interface fast1/0 IGP Id: 1.1.1.1, MPLS TE Id: 1.1.1.1 Router Node id 1 Distribution mode (the Label Distribution's) : the downstream drive mode (Downstream Unsolicited) By default, the cost of an IS-IS interface is 10. Global Pool Sub Pool RFC 3277 TE tunnel reoptimize Remote binding: tsr: 3.3.3.3:0 , tag: 300 tib entry: 2.2.2.2/32, rev 4 Remarks If this time is specified as 0 , the periodic reoptimize will be turned off in all TE tunnels on the router . Of course, you can turn off reoptimize for a single TE tunnel , the command is as follows: 0 kbits/sec Mpls label range 100 199 But in the CSPF algorithm, there can only be one path for a destination. When there are many paths that satisfy the basic conditions (this rule can only be made if TE metric , bandwidth, and related attributes cannot be decided): Establishment of LIB and LFIB tables Network 55.55.55.55 area 0 R1(config)#key chain test R1(config-keychain)#key 1 RFC1195 The NSAP or Net address is used to distinguish devices. In ISO terminology, the data link layer address ( LAN MAC , Frame Relay DLCI, etc.) is referred to as subnet point of attachments ( SNPA ). Since a network device may be connected to multiple links, multiple SNPA addresses are required, but only one OSI network address is required . *Aug 18 11:26:02.546: 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. Then configure it on R1 : Interface fast0/0 In area 49.0001, we can see that all routers flood their own LSPs . LSPs are represented by LSPIDs , such as R1.00-00 . This R1 is the hostname of the device . Here we have the default hostname mapping mechanism. See above. . In addition , 00 after R1 is a pseudo node identifier, and 00 means that the originating router of the LSP is not a DIS , and then the last 00 is a fragmentation flag. Interface fast0/0 Conservative mode : Conservative Retention !! Change the TE tunnel 's setup priority and hold priority to 5 All routers run OSPF IS-IS Level-1 Link State Database: Tu0 Each metric type is 8bits and has the following form: ! i ia 5.5.5.0 [115/158] via 10.1.123.2, FastEthernet0/0 10.0.0.0/24 is subnetted, 4 subnets Label It can prevent the structure of the core transmission network from being exposed due to TTL=0 return error message 10.1.12.2 The configuration of R3 is as follows: The configuration of R1 is as follows: PATH 0x00000011 Minimum Path Bandwidth (bytes/sec): 2147483647 Path Latency (microseconds): 0 MPLS coding Equivalent load balancing in CEF 772 Ip address 1.1.1.1 255.255.255.255 Untagged The two new TLVs are: IGP Neighbor: ID 10.1.23.2 55.55.55.55 [110/31] via 5.5.5.5, 00:00:01, Tunnel0 RFC 3784 Ip address 3.3.3.3 255.255.255.255 - O 2.2.2.2/32 *Aug 18 09:06:07.919: ADSPEC type 2 length 48: In PHP , we have seen the role of implicit null tags, of course, implicit null tags are not limited to PHP . It can also be used in messages with 2 , 3 or more tags in the tag stack . Using an implicit null label (in the LDP , the value is 3 ) on the outbound LSR will inform the penultimate hop router to remove the top label, and the labeled message passed to the outbound LSR will have one less label. In this case,cisco final exam, the outbound LSR does not need to perform the search of two tags. Note that instead of using an implicit null tag, it is not necessary to pop all the tags in the tag stack, but to pop the top tag.