9tut ccna questions

9tut ccna questions

104 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 ldp sync In this way , we can exchange visits between 5.5.5.5 and 6.6.6.6 , on R6 . 1.3 OSI protocol stack terminology Sub Pool Ip cef Other features of the reserved tags between 0-15 are currently not defined. So our available tags are 16 to 1048575 ( 220-1 ) ! ! The change has occurred. In the head router, this will record the labels along the way. Router ospf 1 vrf VPN-A redistribute bgp 2345 subnets network 10.1.12.2 0.0.0.0 area 0 Message Address-family vpnv4 neighbor 2.2.2.2 activate Interface Tunnel0 Link[0 ]:Nbr IGP Id: 10.1.12.2, nbr_node_id:8, gen:47 frag_id 0, Intf Address:10.1.12.1 Does the MTU of both parties match? ! IS-IS adjacency on a multi-access link Outgoing interface Peer LDP Ident: 2.2.2.2:0; Local LDP Ident 1.1.1.1:0 Record Route: 10.1.23.2 10.1.34.3 10.1.45.4 10.1.45.5 Mpls ldp router-id loopback0 mpls label range 200 299 interface fast0/0 Ip router isis Test the transmission process of the data stream, observe the phenomenon Interface fast0/0 10.1.23.3 Send out from the Fa1/0 port. So, R2 replaces the tag with 300 and then throws it to R3 . Except for HELLO packets based on UDP646 , other packets are based on TCP port number 646. *Aug 18 09:06:07.919: min unit=0 bytes, max pkt size=2147483647 bytes My Address: 10.1.23.2 Optional Checksums in IS-IS When we deploy MPLS TE and use OSPF as the TE , OSPF needs to be extended to support MPLS TE . At this time, we can see that the Obit bit is set and can only be seen in DBD packets in this environment. the corresponding option of obit set but the other messages in the option in the obit is still 0 . 55.55.55.55 [110/31] via 5.5.5.5, 00:00:01, Tunnel0 The local device will actively advertise the generated label mapping message to all LDP neighbors. My Address: 10.1.12.1 [115/10] via 10.1.123.2, FastEthernet0/0 SESSION Net 49.0001.0000.0000.0002.00 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. 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. R1.00-00 Mpls traffic-eng tunnels ip rsvp bandwidth R2 , R3 , R4 , and R5 are MPLS VPN Backbone routers. The Backbone IGP protocol running is OSPF , and the process ID is used. We see that in the LFIB of R3 , going to the destination of 1.1.1.1 , there are two label paths for load balancing. Total Allocated BW (kbps) Router-id 5.5.5.5 Router ospf 1 Type : 0x8847 (unicast) upper layer carries MPLS , find LFIB This packet. Fspec: ave rate=20000 kbits, burst=1000 bytes, peak rate=20000 kbits R3.02 The configuration of R2 is supplemented as follows: The TTL is placed in the label header. Turning off TTL propagation prevents the MPLS network from being exposed (by traceroute ). Used in two cases: DIS periodically multicasts every 10s ; the link is just built up in the point-to-point chain. 202 Status: 0x00000011 55000 Switched Fa0/0 R1(config-router)#authentication key-chain test level-1 R1(config-router)# authentication mode md5 level-1 Reservable Bandwidth[6]: Mpls traffic-eng tunnels ip rsvp bandwidth Fa0/0 C 1.1.1.0 is directly connected, Loopback0 Hello IS-IS packets are encapsulated in data link layer frames. Test . 5 : SET 'bit-overload-the suppress interlevel 10.1.12.2 Type 7 length 16: Network 10.1.12.2 0.0.0.0 area 0 Config Parameters: Traffic Engineering (TE) automatic bandwidth feature adjusts the bandwidth allocation for TE tunnels based on their measured traffic load: R2.00-00 Bandwidth , latency , policy constrains For a router that supports IPv6 , the algorithm for performing load balancing on MPLS packets is as follows: Interface eth0/0 The VRF IGP running between PE and CE is OSPF , using process number 1. Interface tunnel0 ! Then by default, R1 goes to .5.5.5.5 and 55.55.55.55 is definitely preferred from E0/1 directly to R5 . But what if we want R1 to go to TE tunnel on .5.5.5.5 and 55.55.55.55 traffic ? Targeted neighbor relationship establishment Route leak Then analyze in detail: The first is R2 on Interface Tunnel0 In the mechanism implemented by MPLS TE ,9tut ccna questions, the head end router of an LSP can learn the topology of the network, and can calculate the optimal route that traverses the network to reach the router at the end of the LSP (not only the metric but also the bandwidth and chain. Road attributes and other elements). Interfaces: TE Metric : Administrative weight *Aug 18 11:26:02.546: Interface tunnel0 * 0x0000000F R1#show ip ospf database opaque-area self-originate The composition of the router , Backbone must be continuous. Ip address 2.2.2.2 255.255.255.255 Bandwidth , latency , policy constrains Mpls traffic-eng tunnels ip rsvp bandwidth Used to request complete LSP information when the database is synchronized on the broadcast link. 0/0/0 Src 1.1.1.1, Dst 4.4.4.4, Tun_Id 0, Tun_Instance 2 RSVP Path Info: Choose the path with the largest " minimum available bandwidth " ! *Aug 18 04:37:06.243: STYLE type 1 length 8 : ! OSPF divides areas based on interfaces. Routers can belong to different areas. 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 . Basic architecture *Aug 18 04:37:06.239: SESSION type 7 length 16: Signalling: connected R1#sh mpls forwarding-table Regular area (non-backbone area) Router(config-if)#tunnel mode mpls traffic-eng Area Address: 49.0001 The configuration of R1 is as follows: The acl-peer is an association ACL used to match the LDP peer to be protected . Note that the matching ACL must be the neighbor's LDP router ID. Mpls ldp router-id loopback0 mpls label protocol ldp *Aug 18 09:06:07.919: Tun Sender: 1.1.1.1 LSP ID: 247 TE metric: 1 Oper: up The configuration of R3 is as follows: *Aug 18 04:37:06.239: Controlled Load Service break bit=0 service length=0 Enable the MPLS TE tunnel feature globally, which is equivalent to a global switch. On CISCO IOS 12.4 , Acl tried it with standard and extended access control lists. If it is unsuccessful, even acl permit any will not work. Matching the route with the prefix list is successful. When there is a problem with the path of R1-R2-R5 , for example , the link between R2-R5 is DOWN , then the TE tunnel will switch to the path-option of the next priority , that is, the dynamic setting mode. Therefore, it will switch to R1-R3-R4-R5 . The configuration of R2 is as follows: i ia 5.5.5.0 [115/158] via 10.1.123.2, FastEthernet0/0 10.0.0.0/24 is subnetted, 4 subnets The interface of each router activates RSVP and MPLS TE tunnel support. LDP non-directly connected neighbors The role of Designated IS ( DIS ) The router will check the received IIH and confirm the parameters. 10.1.12.2 Mpls ldp router-id Loopback0 4 10.1.45.5 0 msec * 0 msec Experimental verification ! Log-adjacency-changes Mainly contains TE tunnel bandwidth request The PoP : receives downstream air sent by the tag assigned to a specific prefix, the value of this tag is 3 , then the LSR to the downstream LSR transmits the prefix data destined time, he will put up top label ( the POP ) for Forward, note that this time only need to check for this LSR Redistribute connected level-1 R2#sh run | Activate RSVP on the interface and configure reserved bandwidth (optional) 55.55.55.55 [110/31] via 5.5.5.5, 00:00:01, Tunnel0 Remote binding: tsr: 2.2.2.2:0, tag: imp-null Ip vrf forwarding VPN-A Next-address 10.1.12.2 All routers run OSPF 10.1.23.3 Send out from the Fa1/0 port. So, R2 replaces the tag with 300 and then throws it to R3 . No output feature configured Fa0/0 Fa0/0 Ip router isis encapsulation frame-relay L2 Next, let's look at the isis database of R1 : Label location Is a group or flow of packets that are forwarded along the same path and are treated the same with regard to the forwarding treatment. R2#sh run | Label Interface eth0/0 Global Pool Sub Pool According to the protection object can be divided into: In this way, when R2 forwards the label data, the data is pushed into the two-layer label, the outer layer is the TE tunnel label 304 , and the inner layer is the VPNv4 label 505. After the label is added to the R3 , the R3 pops the top label, and then the data is Forwarded to R4 , but it is stupid when it comes to R4 , because the 505 tag is generated by R5 , R4 does not know the 505 tag, so it loses the packet.