cisco tests and answers

cisco tests and answers

What is the difference between POP and Untag in Outgoing tag(Label) ? Link connected to: a Transit Network The local device will actively advertise the generated label mapping message to all LDP neighbors. ! MPLS TE and MPLS VPN Network 2.2.2.2 0.0.0.0 area 0 Holding timer : Hold time, default 30S Set-overload-bit suppress interlevel Both TE3 and R5 must establish a TE tunnel . That is, the TE tunnel must be bidirectional. Type 1 length 8 : 75000 75000 Activate the fast-reroute feature on R1 and observe the phenomenon Local tag: 104 *Aug 18 09:06:02.699: SENDER_TSPEC type 2 length 36: Forwarding tagged messages Mpls ip After the increase of this order, relying on the autoroute characteristics calculated, associated tunnel0 mouth of these two OSPF routing metric becomes 9 + 1 : Here 9 is our configuration autoroute metric 9 , where 1 is R5 is Loopback port cost . Note that this only affects R2's own routing . See below for more details on how labels are handled. Interface fast 0/0 ISO addressing Configured on L1/L2 rouer, which is R2 , a default route is generated and flooded to R3 , but not to R1 . Ip address 10.1.23.2 255.255.255.0 Interface Record Route: NONE Label space Inter-domain routing protocol R2#sh isis neighbors Local binding: tag: 104 *Aug 18 09:06:07.919: Path MTU: 1500 ! 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 . OSPF uses different types of LSAs to carry different routing information. Router(config-if)#tunnel mpls traffic-eng bandwidth BW A Forwarding Equivalence Class (FEC) Ip rsvp bandwidth LSPDB If the payload of the MPLS is an IPv6 packet, the load balancing is performed according to the source and destination addresses in the IPv6 header. TCP connection: 3.3.3.3.41954 - 1.1.1.1.646 IGP Neighbor: ID 10.1.23.2 It is also IPv6 because it receives an IP packet instead of a label packet. Intermediate system IS i L2 Fa0/0 Bytes tag Set-overload-bit suppress interlevel external Network 10.1.45.4 0.0.0.0 area 0 Create a tunnel Basic Experiment 1 ( OSPF ) AFI+IDI is used to identify the Domain Precautions: The IETF 's draft-ietf-isis-ipv6-05.txt specifies what IS-IS adds to support IPv6 . It is mainly a newly added two TLVs ( Type-Length-Values ) supporting IPv6 routing information and a new NLPID ( Network Layer Protocol Identifier ). IS-IS is not like RIP and OSPF . These two protocols have separate versions of RIPng and OSPFv3 support IPv6 . MPLS TE can change the bandwidth and attribute parameters of the link through adaptation. Mpls traffic-eng signalling interpret explicit-null verbatim RSVP How MPLS LDP-IGP synchronization works Ip unnumbered Loopback0 tunnel mode mpls traffic-eng tunnel destination 5.5.5.5 Tunnel mpls traffic-eng autoroute metric 9 Configuration example 1 : *Aug 18 09:06:02.699: EXPLICIT_ROUTE type 1 length 52: The interface of each router activates RSVP and MPLS TE tunnel support. Reservable The existence of the established tunnel has changed. The network environment at this moment is as follows: However, there may be such a problem that the LDP connection between R1 and R2 is broken for some reason, but between R1 and R2 . Removal Trigger: configuration changed *Aug 18 09:06:07.919: Ip address 5.5.5.5 255.255.255.0 ip router isis Router(config)#mpls traffic-eng reoptimize timers frequency ? 10.1.34.4 [MPLS: Label 400 Exp 0] 4 msec 0 msec 4 msec Pop Label Downstream active mode : Downstream Unsolicited Mpls traffic-eng router-id loopback0 mpls traffic-eng area 0 OutLabel : FastEthernet1/0, implicit-null RSVP Signalling Info: Or Tunnel Id Interface fast0/0 The configuration of R2 is as follows (the tunnel is not configured temporarily ): [Note] Label behavior of Frame Mode Interface FastEthernet0/0 Router ospf 1 10.1.45.5* In fact, it is for CLNS , and it has been expanded to become an integrated IS-IS , which can support IP routing. 10.1.45.0/24 [110/30] via 10.1.23.3, 00:00:01, Ethernet0/1 Path option 10, type dynamic (Basis for Setup, path weight 3) Interface eth 0/1 Label Mapping message RFC1195 The configuration of R4 is as follows: We complete the experiment as long as the R2 and R4 configuration domain-password can, Rl is a zero-configuration ( Domain Authentication actually level2 LSP embedded for authentication TLV ). The configuration of R3 is as follows: Adjacent router The default MaxAge is 1200 seconds and ZeroAgeLifetime is 60 seconds. When the serial number of the LSP sent by an IS reaches Basic noun Circuit type : 01 means L1 router, 10 means L2 router, 11 means L1/2 router 1144 1.1.1.1 0 [521] ! Debug isis update on R2 R1#sh mpls for Link state messages are used to propagate link and node information in the area (describe the topology of the local network) Record Route: NONE In-label Out intf/label Clns host RouterA 49.0001.1111.2222.3333.00 clns host RouterB 49.0001.4444.5555.6666.00 Mpls traffic-eng tunnels mpls label range 200 299 ISO 8348/Ad2 Then the LSR pushes the IP packet into a tag header, tags 204 , and forwards it out from the F0/0 interface. In CISCO IOS ,cisco tests and answers, CEF switching is the only IP forwarding mode that can be used to mark messages . Therefore , CEF must be enabled on the router when MPLS is enabled . 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. Fa0/0 Interface loopback0 We saw R4 assigned to the LDP label 403 with the prefix 5.5.5.5/32 in the LFIB table of R2 . Bw-based Or, I let the LDP adjacency between R1-R4 be established, then the OSPF between R1-R4 will naturally come up. Well, we now let the LDP adjacency between R1-R4 , and then the OSPF adjacency will be automatically established. Type block This is 1B , which contains a number of important bits: Ip address 5.5.5.5 255.255.255.0 ip router isis Backbone area Route-map test permit 10 router isis !!! Next, R2 receives the tag packet. R2 knows that this is a tag packet from the type field of the Layer 2 Ethernet frame header of this packet, so it looks for its own LFIB table: 10 State: Oper; Msgs sent/rcvd: 13/13; Downstream Up time: 00:04:05 Different LANs on the DIS . 10.1.34.0/24 6B is systemID + 1B of PSN ID IS-IS support for IPv6 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 . The distribution of the label is like this: Interface Ethernet0/0 LDP discovery sources: ! To meet the above requirements, IS-IS is designed as a link state routing protocol and uses the SPF shortest path first algorithm to achieve fast convergence and loop-free networks. IS-IS Transient Blackhole Avoidance Interface Serial1/0 Next-address loose 10.1.34.4 TCP connection: 2.2.2.2.61914 - 1.1.1.1.646 Available bandwidth of the available bandwidth interface In IS-IS , there are three in the HELLO packet: one is the interface point ( Point-to-Point the IS to the IS Hello PDUs ), one is LAN on to Ll Router ( Level-1 to the IS the Hello PDUs the IS LAN ), a method Is the L2 router on the LAN ( Level2 LAN IS to IS Hello PDU ) Is-type level-1 metric-style wide Net 49.0002.0000.0000.0004.00 RSVP Signalling Info: Expense metric Complete basic IP configuration (configuration omitted) Next hop 10.1.12.2, FastEthernet0/0 valid cached adjacency * 0x0000000C Area Address: 49.0001 Reservable Bandwidth[2]: The metric configuration only affects the tunnel endpoint router itself, and does not advertise to other neighbors. But the forwarding adjacency feature is different. Moreover, the two methods of modifying the metric are not used. The autoroute needs to match the autoroute keyword to modify the metric and only affect the configurator itself. In the forwarding adjacency, the metric is modified directly in the tunnel interface . For example , if ISIS is used , then the isis metric command. If ospf is used , it is ip ospf cost .