ccna exam help

ccna exam help

OSPF Router with ID (1.1.1.1) (Process ID 1) The configuration of R3 is as follows: 129 Record Route: NONE 0x80000018 0x001C01 1 ID: path option 10 [8] 10.1.12.2 Start LSP ID : Start LSP ID . Indicates the first LSP ID of the LSP range described in the TLV field . Establishment of LIB and LFIB tables OSPF packets are encapsulated in IP packets, so they are transmitted at the network layer. Interface loopback0 Ip address 10.1.12.1 255.255.255.0 Do not need to explain it again? At R4 , R4 pops the top label and forwards the packet to R5. Up time: 00:00:33 Tunnel mpls traffic-eng forwarding-adjacency Reservable Bandwidth[5]: Overview Next, R1 calculates another alternative path to R7 through the existing information : R1-R2-R4-R5-R7 , this path passes CSPF 75000 Router-id 2.2.2.2 ! (Tunnel0) Destination: 4.4.4.4 The configuration of R4 is as follows: Can form adjacencies with other L2 (or L1/L2 ) routers i L1 2.2.2.0 [115/10] via 10.1.123.2, FastEthernet0/0 5.0.0.0/24 is subnetted, 1 subnets About Explicit Path 10.1.12.2 Ip router isis encapsulation frame-relay Going is the tunnel . therefore: Clear text interface authentication The loopback0 address space of all devices is xxxx/32 , and x is the device number. DIS send HELLO interval ordinary packet router of 1/3 (default 3.3s ) i*L1 0.0.0.0/0 [115/10] via 10.1.123.3, FastEthernet0/0 Take a look at the routing table for R1 : R1#traceroute 55.55.55.55 0x3B83 This behavior will continue until the RESV message arrives at the head end router of the TE tunnel LSP . That is, after the request is made by the head end router, the label is advertised hop by hop from the tail router to the head end router. This shows that the TE tunnel uses the downstream passive DOD label distribution. 1 10.1.46.4 128 msec 152 msec 120 msec 1194 Now let's consider another scenario. Suppose we add a physical connection between R1 and R5 . In order to facilitate the experiment, I directly pull a line between R1 and R5 . Everyone has the right to have multiple routers in this new path. Play the imagination and kiss: Pop Label Frame-relay map ip 10.1.123.3 103 broadcast frame-relay map clns 102 broadcast Mpls traffic-eng tunnels mpls label range 300 399 !! Primary tunnel Now we can try to modify the TE tunnel configuration of R1 : Protocols support The configuration of R3 is as follows: Mpls ldp router-id loopback0 mpls label protocol ldp The configuration of R2 is as follows (the tunnel is not configured temporarily ): Let's take a look, why is it exposed to network information? Suppose A below router E , E made to be a packet to D under F. , The data packet is A tag the transferred B , assumed that the BC loop appears between subsequent label TTL is decremented to 0 , since the TTL value The setting is very small, so very quickly, the TTL is decremented to 0. At this time, B (message discarder) will send an ICMP error message back to E. Then, if B has E route (or label), B will The ICMP error message will be sent directly back to E. If not, B will continue to tag the error message and gradually pass it to D , D.As the PE , about E route, then back to the label and then loaded on E . Then,ccna exam help, no matter what the situation, the final E can receive the ICMP error message generated by B.