what to study for ccna exam

what to study for ccna exam

We found that the attached-bit before the LSP generated by R2 is gone, but the Overload-bit is set . Now let's go look at the routing table. R4#sh isis da ! Mpls traffic-eng tunnels ip rsvp bandwidth 10.1.34.4 [MPLS: Label 400 Exp 0] 0 msec 12 msec 8 msec Uptime: 9 minutes, 33 seconds Selection: reoptimation Router isis i* L1 Router(config-if)# mpls traffic-eng attribute-flags ? 10.1.34.0/24 OutLabel : FastEthernet1/0, implicit-null RSVP Signalling Info: By default, IS-IS of the LSP maximum survival time of 1200s , In CISCO IOS , a re-optimization of a TE tunnel is done every 1 hour by default . Reservable Bandwidth[0]: Protocol overview 10.1.34.4 Interface Tunnel0 Router ospf 1 Untagged R1#sh mpls traffic-eng topology 1.1.1.1 Prefix Traffic using traffic engineering uses source-based routing instead of routing based on destination IP address OSPF and ISIS also have mechanisms for periodic flooding IP Address: Metric: 10 Fast tag rewrite with Fa0/0, 10.1.12.2, tags commit: {203} via 10.1.12.2, FastEthernet0/0, 0 dependencies Remote binding: tsr: 2.2.2.2:0, tag: imp-null tib entry: 10.1.13.0/24, rev 8(no route) Ip unnumbered Loopback0 tunnel destination 4.4.4.4 tunnel mode mpls traffic-eng LSP Seq Num Ip address 3.3.3.3 255.255.255.255 Interface Tunnel0 1 Peer LDP Ident: 3.3.3.3:0; Local LDP Ident 2.2.2.2:0 TCP connection: 3.3.3.3.62244 - 2.2.2.2.646 Switched R2.02 Fa0/0 R2(config-if)#mpls traffic-eng administrative-weight 100 Tspec: ave rate=0 kbits, burst=1000 bytes, peak rate=0 kbits RSVP Resv Info: 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 Router(config-if)#tunnel mode mpls traffic-eng Interface eth 0/0 *Aug 18 04:37:06.239: parameter id=127, flags=0, parameter length=5 201 Can use the default or use this command to modify Router(config-if)# bandwidth ? Router ospf 1 If the weight issue orders without the level parameter, the default is as shown level2 parameters, that is, inject external routes into level2 in this way level2 area can learn to this external routes, but level1 area in Can't learn because R2 is at level1 129 10 Label Ip address 2.2.2.2 255.255.255.255 *Aug 18 09:06:07.919: SESSION type 7 length 16: Focus on the 2.2.2.2/32 entry. The current outgoing label is pop , which is an empty label. *Aug 18 09:06:07.919: 10.1.24.2 (Strict IPv4 Prefix, 8 bytes, /32) In the Level1 link state database. Each zone in the IS-IS domain has a unique Level1 link state database. The shortest path is calculated by the SPF algorithm. How MPLS LDP-IGP synchronization works 5.5.5.5/32 IS R1.00 10.1.34.3 10.1.34.4 R2 redistributed direct route 2.2.2.0 is gone, inter-area route is still, and R1 no longer uses R2 as the next hop of the default route. Note that the LSP sent by R2 is also overload-bit set. . The Auto Route is configured on the MPLS TE tunnel head-end router and only affects the OSPF route selection of the head-end router . Router-id 2.2.2.2 CSNP Length Type escape sequence to abort. Tracing the route to 5.5.5.5 About Explicit Path Router(config-if)# mpls traffic-eng path-option x {dynamic | explicit name y } [ lockdown ] 205 R1#deb ip rsvp dump-messages The Global Pool Sub Pool !! interface is the bandwidth pool for each priority tunnel A label switched path (LSP) Router ospf 1 R1#show isis neighbors So far, the basic configuration has been completed. Now let 's create a TE Tunnel on R2 and R5 : Host TE tunnel is one-way (Tunnel0) Destination: 4.4.4.4 5.5.5.5(0) 3 10.1.34.4 160 msec * 140 msec Interface loopback0 Interface Tunnel0 Interface Ethernet0/0 Therefore, in an NBMA network, such as a frame relay environment, it is strongly recommended to use the P2P sub-interface to run ISIS . Mpls traffic-eng tunnels ip rsvp bandwidth Router-id 1.1.1.1 Mpls traffic-eng router-id Loopback0 mpls traffic-eng area 0 Neighbor 10.1.24.4 remote-as 45 no auto-summary Test and see the forwarding path of the data. So if you want to load balance based on messages ? Assuming the bandwidth of the local physical outgoing interface is 100M , the default reservable bandwidth of rsvp is 75% . Here is 75M. Obviously due to the lost and R3 direct link, R1-R3 between the LDP adjacency hung up, in terms of natural LIB table, before R3 pass over the bundled label will be lost, and now, if R1-R3 Between the link replies,what to study for ccna exam, they have to re-establish LDP adjacency and resend the label bundle. Ip cef 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. 75000 LSP , using LSP to carry all routing information Fa0/0 Each metric type is 8bits and has the following form: From the debug information of R1 , you can see: R1 , R2 , and R3 run OSPF to advertise direct connection and their own loopback interface. And LDP is activated on the straight connector . Now is a normal situation, 2.2.2.2/32 BGP routing problem, well, now we use the loopback interface on R1 and R4 to establish IBGP adjacency, the problem is solved. At this time R4 , the go 5.5.5.5 next hop of the R1 of Loopback port addresses, R4 at destined to 5.5.5.5 of the IP when the pressure package label, use is 1.1.1.1/32 routing tag, The same is true for R3 and R2 , then the label package can be opened through 1.1.1.1/32 . *Aug 18 04:37:06.239: version:1 flags:0000 cksum:DEB3 ttl:255 reserved:0 length:132 Cisco Router 's ISO addressing 0/0/0 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. *Aug 18 09:06:07.919: *Aug 18 11:26:02.546: How labels are handled Frame-relay map ip 10.1.123.3 301 broadcast frame-relay map clns 301 broadcast *Aug 18 09:06:07.919: Layer 3 protocol ID: 2048 Mpls traffic-eng tunnels mpls label range 500 599 Interface Serial0/0 (Tunnel0) Destination: 5.5.5.5 4.4.4.4/32 Config Parameters: 42000 IS-IS packets carry all easily expandable information using TLV fields Show mpls ldp discovery show mpls forwarding-table AutoRoute Overview Tag or VC Exit-address-family Interface loopback0 Router ospf 1 The router uses PSNP to acknowledge multiple LSPs on the point-to-point link (the next one in the middle) The above is the debug information under normal circumstances . Related standards: Ip address 5.5.5.5 255.255.255.255 10.1.56.5 [MPLS: Label 505 Exp 0] 4 msec 0 msec 0 msec Interface fast 0/0 Interface Ethernet0/1 *Aug 18 04:37:06.239: Controlled Load Service break bit=0 service length=0 The checksum calculation knows the end of the packet starting from the field after the remaining time-to-live field in the LSP . When the LSP copy is propagated between routers in the network, its checksum field is not modified. Basic Experiment 2 ( IS-IS ) Interface fast 0/0 We started CEF on R3 . In fact, in CEF , the default load balancing method is destination-based load balancing. CEF 's 5.5.5.5/32 How long in msecs to wait upon flooding a down forwarding adjacentcy Fa1/0 MPLS VPN Architecture CCSP Edition Local tag Backbone area Remove ( PoP ) State: Oper; Msgs sent/rcvd: 26/22; Downstream Up time: 00:09:33 By default, IS-IS of the LSP maximum survival time of 1200s , 403 LSP Database LSP database Ip cef ! i ia 5.5.5.0 [115/158] via 10.1.123.2, FastEthernet0/0 10.0.0.0/24 is subnetted, 4 subnets 10.1.34.0/24 Test 1 : set-overload-bit Network 1.1.1.1 0.0.0.0 area 0 The configuration of R3 is as follows: The initial configuration is as above. In the current environment, R1 does not activate fastreroute , and R2 does not deploy a protective tunnel . First, in R1 the debug ip rsvp dump-messages R3.00-00 Interface fast 1/0 10.1.12.2 L1/L2 router re-releases external routes into IS-IS ( to level1 ) Ip address 10.1.45.4 255.255.255.0 The term link is a path between two ISs (routers). When two adjacent SNPAs can communicate, the link is in the UP state. NET R2#show mpls traffic-eng fast-reroute database In this experimental test, we announced the direct-connected segments of R1-R5 and R4-R6 in OSPF . The TEDB already has link state information in all areas, so there is no need to use the IGP routing protocol. Address-family vpnv4 neighbor 2.2.2.2 activate 128 2 R3(config)#Interface tunnel 0 !! Change the TE tunnel 's setup priority and hold priority to 5 Mpls traffic-eng tunnels ip rsvp bandwidth Interface eth0/1 Min unit=0 bytes, max pkt size=2147483647 bytes R6#traceroute 5.5.5.5 soure 6.6.6.6 Set the synchronous holddown timer to 5S , so that after 5S times out, R1-R4 establishes the OSPF adjacency. Src IP addr: 10.1.12.2; Transport IP addr: 2.2.2.2 Hold time: 15 sec; Proposed local/peer: 15/15 sec Reachable via 2.2.2.0/24 55.55.55.55 [110/31] via 10.1.23.3, 00:03:44, Ethernet0/1 10.1.23.2 Mpls traffic-eng tunnels ip rsvp bandwidth Understand the establishment process of LDP neighbor relationships. AutoRoute Intermediate LSRs - Intermediate LSRs receive an incoming labeled packet, perform an operation on it, switch the packet, and send the packet on the correct data link. 101 ! The OSPF adjacency cannot be established, but R1 has only one available path to reach R2 , so OSPF adjacency is established unconditionally. At the same time, R1 and R2 will directly announce the 10.1.12.0/24 direct link, which will be advertised with the largest metric 65535 . The purpose of this is that if the network environment is a redundant link environment, then the metric of the link can be made the worst from the perspective of the IGP , so that the LDP path bypasses the link.