ccent ccna

ccent ccna

! Image Image Image Route matching tool PS : It should be noted that there will be class and classless route lookup methods, which are distinguished from classful and classless routing protocols. Image The configuration of PE1 is as follows: On the Internet, like R2 such 6to4 relay router still a lot. There are some public 6to4 relays. E.g: The MPLS Domain consists of three routers: PE1 , P , and PE2 . The IGP protocol running in the domain is OSPF , and the process ID is 100 . Each of the three routers announces its own loopback port into Core 's OSPF . The address of Loopback is xxxx/32 , and x is the router number, such as PE1 is 2.2.2.2 , P is 3.3.3.3 , and PE2 is 4.4.4.4 . Therefore, R1 will send an ICMPv6 Type=137 redirect message to R3 to inform R3 that it is going to destination 2222::3 , someone is better than me, and the key information contained in this ICMPv6 message is R2 is LINKLOCAL address . The message is as follows: Route-map nat2 permit 10 match ip address 1 Ip route 0.0.0.0 0.0.0.0 192.168.123.1 --- Of course, R3 should also be configured similarly. 10.1.13.3 RA 134 Default route delivery Image Ipv6 nat Route-map test permit/deny 20 Ip address 10.1.12.1 255.255.255.0 The following is our CE1 , ping 2001:5555::5 , then capture the packet on the Fa1/0 port of PE1 : RIPv1 update and receiving rule verification When the packet enters the router, the router strips the Layer 2 information and then looks up the destination IP address in the CEF table for forwarding. The result of the forwarding decision will point to a neighboring entry in the adjacency list, in which the second layer of character letters that need to be rewritten can be found. Image [Experiment 6 ] There are subnet routes, the subnet route prefix length is different (matching and mismatching), and the matching route is taken. Image Based on agreement Configure OSPF unicast updates: Image On the other hand, we capture the package: RFC1723 defines an acceptance control switch When 10.1.1.2 is reachable, the track object is true command Redis static route-map test *> 2001:1111::1/128 Network 3.3.3.0 mask 255.255.255.0 Redistribute rip subnets tag 1111 Ip policy route-map x 10.1.13.3 command There are 1.1.1.0 , 2.2.2.0 routes on R1 . Via FE80::FFFF:FE10:2, Serial0/0 OI 2001:34::/64 [110/192] Ipv6 ospf 100 area 1 interface serial0/1 We see that the ICMPv6 message of this RS is the head of IPv6 , and the head of IPv6 is the head of IPv4 . Note the header of the outer IPv4 , the source is 1.1.1.1 , the purpose is 2.2.2.2 But what if the A route is an OSPF external route? 2001:5555::5/128::FFFF:4.4.4.4 nolabel/403 Ipv6 enable When OSPF to IBGP when routes are heavy, because the OSPF of AD than IBGP of AD should be small, so there is no problem of sub-optimal routing path or loop: OSPFv3 configuration The configuration of PE2 is as follows: Router responds to this RA where there is a ICMPv6 of the Option , which contains the ISATAP router IPv6 prefix. and The session between Source and Destination is established. ( Routing Table ) , the routing table is loaded with routing entries ( routes ) learned by the router . The routing entries are composed of routing prefixes (destinations associated with routes), routing information sources, outgoing interfaces, or next hop IPs . The router obtains routing entries and maintains its own routing table in a static or dynamic manner. This prefix will not be included in the RA message. By default, CISCO IOS turns off this no-advertise , which means that the prefix will be included in Image The transition mechanism of V4 to V6 discussed above is basically the case where V4 and V6 coexist. So if there is a need for mutual access to the V4 single protocol and the V6 single protocol network? PBR (Policy Routing) ICMP redirects are always sent Ipv6 nd reachable-time !! A neighbor confirmed after its accessibility by an event, during which time the neighbor is considered reachable, the default 30S (in CISCO IOS on the show out, the book says It’s 30min , it’s estimated to be wrong.) DHCPserver configuration Image Ipv6 address 2004::4/64 R2#show cef interface f0/0 FastEthernet0/0 is up (if_number 4) Ivv6 nat v4v6 pool v4v6-pool 2001:2:: 2001:2::FFFF:FFFF prefix-length 96 ipv6 nat v4v6 source list 1 pool v4v6-pool Tunnel mode ipv6ip 6to4 interface fast1/0 Next hop 10.1.12.2, FastEthernet0/0 valid adjacency Ipv6 router ospf 1 router-id 5.5.5.5 Ip route 172.16.1.32 255.255.255.224 192.168.23.3 But on R1 : If you want to turn off ICMP redirects, you need to use no ip redirects on the interface . OI 2002::1/128 [110/64] Deployment points Ip cef Originally, the IPv4 prefix of 3.3.3.0/24 passed by R3 , NH is 254.128.0.0 , which is a reserved address. This address is of course illegal, so R2 ignores this route directly. Solution, may be R3 to the R2 do out direction route-Map , and provided IPv4 prefix NH2 , such as: 1111 10xx xxxx xxxx Matching with the detailed route 172.16.32.0/24 , so eventually these two routes will be filtered out, which is inconsistent with our needs. In fact, this is the drawback of using a standard ACL to match the route, you can only match the network number of the route, and can not further match the prefix of the route. Ipv6 prefix-list loopb permit 2003::3/128 route-map test permit 10 When one or more consecutive 16- bit fields are 0 , the ::: is available, but only one is allowed in the entire abbreviation: No shutdown Ipv6 address 2001:12::1/64 Set ip next-hop ip1 Set ip next-hop ip2 Image Image IPv4- compatible addresses are used for transition mechanisms such as automatic ipv4- compatible tunneling and NAT-PT (see the IPv6 Transition Technology section of this document for details). Static NAT-PT (two-way) 203/nolabel When the GW connects to the outgoing interface of ISP2 and DOWN (that is, ISP2 hangs), then switch to ip next-hop recursive, which is ISP2. F000 – F7FF A specified 32bits of Router-ID Now 2001: 5555 :: 5 with VPNV6 label, but also the level of data is impenetrable MPLS BACKBONE , because the P routers do not recognize this tag. Therefore, it is necessary to add another tag so that the intranet tag and data payload can be transmitted in the MPLS BACKBONE . This outer label is assigned by LDP . None Ipv6 dhcp client pd test After the trigger update is enabled, the routers at both ends of the link no longer send routing updates periodically. Of course,ccent ccna, another problem arises. If the route in the routing table expires, it will hang, so it is necessary to trigger the update. It must be configured on both interfaces of the link, so that the routing update will be marked permanent for permanent. Under normal circumstances, the data is preferred to go ip next-hop , that is, go ISP2 Prefix announcement overview RIPv1 update and receiving rule verification Install the IPv6 protocol stack Image 1/0/0 Ipv6 address 2001:0001::FFFF/64 Ip address 10.1.34.3 255.255.255.0 Router ospf 1 By default , Cisco routers enable fast switching or optimal switching or cef switching instead of process the Next-Hop recursive This (recursive next hop ) broke the characteristics of the traditional hop-hop interface must be directly connected under the router IP restrictions. Recursive next-hop may not be directly connected to the network, as long as the relevant routes in the routing table are reachable. Generally, the recursive next-hop is unreachable, and the data will be handled by the route (generally the default route is matched).