ccna academy

ccna academy

724 O 10.1.34.0 [110/3] via 10.1.12.2, 00:00:39, FastEthernet0/0 Area Address(es): 49.0001 SNPA: cc03.1ab0.0000 State: Oper; Msgs sent/rcvd: 13/13; Downstream Up time: 00:04:05 Next hop 10.1.34.3, FastEthernet0/0 via 10.1.15.0/24 valid cached adjacency Fa1/0 Fa0/0 The label that the tail router advertises to the penultimate hop router is "explicit empty label". However, if the penultimate hop router runs CISCO IOS , it will understand this in the form of an implicit null label, that is, By default, in the TE tunnel, the message sent by the penultimate router to the tail router is unlabeled (or the top label has been removed). 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 2.0.0.0/24 is subnetted, 1 subnets RSVP Signalling Info: Network 10.1.34.4 0.0.0.0 area 0 Reference book Src 1.1.1.1, Dst 5.5.5.5, Tun_Id 0, Tun_Instance 31 RSVP Path Info: Mpls ldp router-id loopback0 75000 kbits/sec, *Aug 18 11:26:02.546: Local 104 [Supplement] The non-pseudo-node LSP represents a router , including all ISs and LANs connected to this router . The ACL filters out LDP packets. This prevents LDP adjacency between R1 and R4 from being established. Let's observe the phenomenon. Router isis The LSP is transmitted to R2 all the way , and in R2, the pop-up label becomes an IP packet and then forwarded to R1 . R1 then forwards the IP packet to R5 and fixes it. Checksum: 0x6FEB Length: 132 4 10.1.12.1 1060 msec 984 msec 1080 msec ! 5.5.5.5(0) R2.00-00 A device that supports and activates MPLS . It is capable of understanding MPLS labels and of receiving and transmitting a labeled packet on a data link. Three kinds of LSRs exist in an MPLS network: i L1 ! Pop tag ! Router-id 3.3.3.3 Ip explicit-path name R2R4 enable next-address 10.1.12.2 5.5.5.5 Mpls label rangempls label range 200 299 Bw[6]: Use the exclude-address command to control the LSP from passing through a node (interface or router). You can use this keyword to match an interface IP or an MPLS TE router ID to let the tunnel path bypass a certain link or a router. *Aug 18 11:26:02.546: version:1 flags:0000 cksum:CA2B ttl:255 reserved:0 length:160 The configuration of R3 is as follows: RESVErr is sent to the tail router Ip cef Usually LDP sessions are established between directly connected LSRs , but in some cases, a remote, or destination-based LDP session, such as a TE tunnel in an MPLS VPN , may be required . When a link flapping occurs, a destination-based LDP neighbor can improve the label convergence time relative to the directly connected LDP peer. Because if it is directly connected LDP neighbors,ccna academy, two LSR link between if DOWN out, then LDP session will DOWN , however the purpose of the LDP session, another alternative paths can be used to carry LDP TCP packets , so, even if even if the link DOWN out, LDP session is still valid, all tags will be retained, while the link may soon resume LIB label in the update to LFIB go.