ccna practice exam free download

ccna practice exam free download

10.1.34.3 10.1.34.4 IS-IS routers belong to only one specific area IP 1.1.1.0 255.255.255.0 IS R3.02 Such as LDP ID = 1.1.1.1:0 Ip address 55.55.55.55 255.255.255.255 Tspec: ave rate=0 kbits, burst=1000 bytes, peak rate=0 kbits RSVP Resv Info: 202 DIS advertises all neighbors in the LAN in the "pseudo-node LSP " (similar to the LSA in OSPF ) Local binding: tag: imp-null R2 (config)#router isis Network 10.1.23.2 0.0.0.0 area 0 NHop ( Next Hop Router ): Next hop router, PLR next hop router 0 kbits/sec *Aug 18 11:26:02.546: TE tunnels are an aggregation of traffic flows of the same class (bandwidth , etc.) which are placed inside a common MPLS LSP AutoRoute defect 0.1.123.2 Local Circuit ID Local circuit ID is a link identifier. The identity of this circuit is assigned by the router that sent the Hello PDU and is unique on the interface of the router. At the other end of the point-to-point link , the local circuit ID in the Hello message may or may not be the same value. The interface of each router activates RSVP and MPLS TE tunnel support. 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. *Aug 18 09:06:07.919: parameter id=127, flags=0, parameter length=5 R1#show ip ospf database Link state messages are used to propagate link and node information in the area (describe the topology of the local network) Physical Bandwidth: 100000 kbits/sec Res. Global BW: 75000 kbits/sec Res. Sub BW: 0 kbits/sec Downstream:: 10.1.34.4 Here are a few things to note: *Mar 1 00:00:32.755: ISIS-Upd: Building L1 LSP NLPID: In the LAN , SNPA refers to the MAC address. Route metric is 168, traffic share count is 1 Ip router isis R3 The configuration of R2 is supplemented as follows: R2#show mpls traffic-eng fast-reroute database Interface Tunnel0 10.1.56.5 [MPLS: Label 505 Exp 0] 4 msec 0 msec 0 msec Configure path protection on R2 and observe the phenomenon. Imagine if AB link between carrying a lot of the Tunnel , then when this root link DOWN out of time, will likely trigger a large amount in a short time PATHtear and ResvTear , so how to optimize it? 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 . AutoRoute: disabled LockDown: disabled Loadshare: 20000 bw-based auto-bw: disabled Network 10.1.45.5 0.0.0.0 area 0 R3.00-00 Ip address 10.1.34.4 255.255.255.0 Admin: up 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 . Tunnel mpls traffic-eng autoroute announce Flowspec 10.1.45.4 Mpls traffic-eng router-id loopback 0 mpls traffic-eng level-1 Auto Route : Based (internet per-Platform ) compared to the label space-based interface ( per-interface ) security label space to lower Mpls traffic-eng tunnels mpls label range 200 299 The above command will add or subtract z from the original cost of the route ( the range of z is -10 to 10 ) The configuration of R1 is as follows: Configuration example LDP is in Frame Mode . The LSR assigns a label to each route. The local direct route is assigned a POP. ISs flood new LSPs to all neighbors Mpls traffic-eng tunnels ip rsvp bandwidth 20bits The interface of each router activates RSVP and MPLS TE tunnel support. 19 From the debug information of R1 , you can see: O Ip explicit-path name R2R3R4 enable next-address 10.1.12.2 Expense metric is optional. The transmission cost of the link is not supported. Bw[7]: Turn off TTL propagation BDR 3.3.3.3 DIS send HELLO interval ordinary packet router of 1/3 (default 3.3s ), which ensures DIS when a failure occurs can be more quickly found. LSP The configuration of R1 is as follows: *Aug 18 09:06:07.919: ADSPEC type 2 length 48: Now the initial environment, R1 can learn inter-area routes, and R2 locally re - routes to level 1 route 2.2.2.0 . Of course, since R2 sets the attached-bit , R1 also generates a default route to R2 . Network 10.1.23.3 0.0.0.0 area 0 A route 10.1.1.0/24 on E was advertised, and now it is summarized on C. The summary route is 10.1.0.0/16 and is advertised to B. TE can provide a solution to avoid link overload by controlling traffic or partial traffic. Let's make a comparison: [0]: Fa0/0 PATH After the feature is activated, both R3 and R5 advertise the existence of this tunnel (in the form of a direct link) within the zone . Equivalent to having one more path (virtual path) in the topology environment. I don't want L1-router to generate this default route, or more rigorously, we don't want L1\L2 router to press att , the method is O bits are defined in OSPF in the option field is used to indicate whether the router has the ability to send and receive opaque the LSA . The R2 re-released 2.2.2.0 external route is still there; the inter-area route is gone, except for a R2 local direct connection of 24.0 ; in addition, R1 still does not use R2 as the next hop of the default route. Experimental results: End host. For example , the ISO CLNP workstation searched by the ES-IS protocol . C 75000 R3 All interfaces of ospf area0 will automatically activate LDP. R3.00-00 Interface Loopback0 Mpls traffic-eng signalling advertise implicit-null [acl x] IS-IS Level-1 LSP R3.02-00 Untagged Select the path with the least number of hops ! C . There is a small detail, noted that the distribution of the label no concept of split horizon, that although B may be from C to learn the route to X , but B still will be prefixed with X passed to the bundled label C . C will also put the label passed from B in the LIB ,ccna practice exam free download, but don't worry about loops, because LDP can prevent loops by means of IGP routing protocol. The data packet is stamped by A , and the TTL value of the label header is copied to the TTL in the IP header (of course, minus 1 first ), and as the data frame is transmitted in the MPLS network , the TTL value in the MPLS header is decreasing to 0. Then discard until the data frame out of the MPLS domain, then the TTL in the IP header will start working. At the time of outbound, the TTL in the tag header is decremented by 1 and copied to the TTL in the IP header .