ccnp switch questions

ccnp switch questions

TCAM table Flag: 0x860 Further, the summary is transmitted to the route D after, D will continue to B to pass, and as summarized route from C , thus reaching D of AS400 Configure the DAI to occupy the size of the log buffer (the maximum number of entries), the interval is 0-1024 Configuration last modified by 0.0.0.0 at 3-5-93 00:11:48 Command MD5 digest : 0x49 0x3C 0x1F 0x79 0x15 0x00 0xC7 0xAE 0x0E 0xDC 0xDD 0xEF 0x93 0xA5 0xB6 0x26 Supported for switch ports and routed ports FastEthernet0/0 The smaller the total cost of the switch to reach the root switch path, the better, related to the interface bandwidth. The TAG field ( 32bits ) is only present in the external LSA . ( Well-known mandatory ) 10.1.23.2 RIPv1 Type 5.5.5.5 ( metric 2 ) from 5.5.5.5 (5.5.5.5) You can also use the show ip dhcp bingding to capture the client-identifier of the client on the server. Sw(config-vlan)#private-vlan association 201,202 Network 100.0.2.0 mask 255.255.255.0 If you want to turn off ICMP redirects, you need to use no ip redirects on the interface . Default 30s , RIP update cycle RIP update source problem RIP re-advertises routes to OSPF : Scp: Database agent URL A strange phenomenon has appeared. It seems that R4 does not reflect the route from R5 to R3 . Why? In theory, the RR will learn from non- client of IBGP neighbor to route reflection to their Client , but it is clear, in this experiment, R4 and did not learn from R5 route reflection to their Client . ( Optional ) RIP based on rumor updates Gateway of last resort is 172.16.12.1 to network 192.168.1.0 We expect the effect of the above configuration is implemented R1 to 100.0.1.0 routing setting MED = 100 , 2.0 disposed MED = 200 is , while R2 to 100.0.2.0 disposed MED = 100 , 1.0 arranged MED to 100 , respectively, to the respective property The EBGP neighbor takes effect, so the MED attribute will be passed along the route in AS345 and finally arrive at R4 . NEXT_HOP on shared Media (operation on shared media) BGP state machine Set extcommunity cost pre-bestpath 1 10 When both DSAP and SSAP take a specific value of 0xaa , the 802.3 frame becomes the ETHERNET_SNAP frame. Switch(config-if)# switchport protected Routing, then: Network Improve security, reduce the number of subnets, and increase IP utilization Lease expiration Example 2 : FastEthernet0/0 TYPE field is 0x80 300 Two-way re-release of OSPF and RIP In Ethernet, different media access methods are provided for different duplex modes: Router bgp 345 200 i The BGP router appends its AS number to the AS_PATH only when the update message is sent to another AS ( EBGP peer ) . This sentence also implies another meaning, that is, if you want to modify the AS_PATH attribute, you must execute the policy on the AS border router, and the policy of modifying the AS_PATH for the IBGP neighbor is invalid. Configure BPDU is 0x00 and TCN BPDU is 0x80. When the previous eight routing principles fail to optimize the optimal route, and the maximum-paths [ibgp] n is configured under the BGP process , and the value of n is 2-6, the equivalent load balancing will be performed. Let the CISCO router ignore the AS-path attribute during its decision making process When a data frame is sent from the Hybrid port, the switch determines whether the attribute of the VLAN on the port is Untag or Tag . If it is Untag , first strip the VLAN tag of the frame and then send it ; if it is a Tag , send the frame directly. DoS attack. Then it is recommended to limit the ARP message threshold on the interface . Interface vlan 100 ! 32768 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, r RIB-failure, S Stale *> The default is 10 , this default value is generally sufficient. Network [ac 1-2]$ Route-map test permit 10 Use 224.0.0.9 Represents the upper layer protocol ( BPDU ), which is always 0. Modify the AD value of EIGRP The BGP configuration of R4 is as follows: VTP Traps Generation Maximum life ^(100|200)$ After the data transfer is completed, A to B transmits a data frame to tell B releasable attachment, the communication ends. In this way, the entire network is interconnected. Note that when redistributing routes to OSPF , redistribute rip subnets , this subnets Idle AS does not compare the MED values. In other words, for multiple paths, the MED is compared only if the first AS in AS_SEQUENCE is the same ; any leading AS_CONFED_SEQUENCE will be ignored. MED only affects traffic between directly connected autonomous systems, and does not pass across ASs. table of Contents BVI Bridge-Group Virtual Interface MD5 digest : 0x49 0x3C 0x1F 0x79 0x15 0x00 0xC7 0xAE 0x0E 0xDC 0xDD 0xEF 0x93 0xA5 0xB6 0x26 Information, so that ISP1 is hanging, so the data of the PC accessing the 100 network is switched to ISP2 , and the network is constantly 100 In the establish state, the status prompt is not displayed, and a number indicating PfxRcd is displayed , that is, the prefix entry received from the neighbor. Multiple paths have the same RouterID because they are received from the same router. Another recommended solution is to adjust the management distance of the routing protocol: Port-channel interface cannot be the destination interface of SPAN ( Well-known discretionary ) The configuration of R4 is as follows: Switch(config-if)# switchport mode encapsulation {dot1q | ISL} RIPng DHCP relay 16 bits RIP V1 supports a maximum of 6 and defaults to 4 equivalent load balancing. And does not support verification. V2 supports verification. Metric \ Inter- VLAN routing DAI relies on DHCP snooping technology. In a network environment where users dynamically obtain IP addresses, we deploy DHCP. Not advertised to any peer Local *Mar 4 07:02:23.473: DHCPD: relay information option exists, but giaddr is zero. Router bgp 300 2.2.2.2 Bibliography Network 100.0.1.0 mask 255.255.255.0 Consider the case where R2 is RR , and R4 and R5 respectively declare loop Rule verification (the AS number in the federation does not participate in the AS_PATH length calculation) Example 2 : Both R1 and R2 inject 100.0.1.0 and 100.0.2.0 into BGP using network . The configuration of R2 is as follows: During the above events, the contents of the following fields will not change: These two attributes are used to prevent ringing within the federation and member AS . The DHCP server got an illegal address and eventually the PC could not access the Internet. Preferably EBGP route 20 Invalidation timer If it is injected through the aggregate-address command, next-hop is equal to the update source IP of the summary router . If the penalty value exceeds the pre-set threshold - the suppression limit: the penalty value reaches this threshold,ccnp switch questions, the route is suppressed, ie not released, until the N half-life, the penalty value is reduced to another threshold: re-use threshold (de-suppression threshold) ), the suppression of the route is lifted. Through the above configuration, the BGP neighbor relationship can be established, let's show it: On Authentication Type Configuration example 46 The above command calls the defined policy-list in the route-map ; multiple policy-lists can be called in a route-map . 32768 Route-map test permit 10 STP topology change Protocol mechanism Network 100.0.1.0 mask 255.255.255.0 VTP operation BGP has three management distances, 200 learned from IBGP and 20 learned from EBGP . This is because the design concept of BGP works. Next Hop The interface will not send BPDUs , and will also ignore received BPDUs. Regular updates, broadcast updates, routing table updates; according to rumors; distance vector routing protocols do not understand network topology Switch(config-if)# switchport port-security aging static The above interface loses the portfast and bpdufilter features immediately after receiving the BPDU , and becomes an ordinary spanning-tree interface. Metric Authentication Type Path attribute In update their ARP table or will receive the ARP before forwarding the message out to check legality, mainly to see the ARP packets in IP and Default route R1 and R2 run OSPF , and announce the direct connection network and their respective LOOPBACK interfaces. R1 LO1 is 1.1.1.1 and R2 LO1 is 2.2.2.2. Interface vlan 100 STP topology change Aggregate-address 192.168.0.0 255.255.0.0 as-set advertise-map adv Y The configuration of R4 is as follows: 100 The configuration of R3 is as follows: Suppress-map unsuppress-map advertise-map inject-map Router(config-dhcp)#default-router [host address] Router ospf 100 Flooding the MAC table to the above port Route Control Overview 77 ? OpenSent *>i100.0.2.0/24 192.168.255.0/24 . Note change, replace-as keywords allow R2 to secAS of EBGP when sending routing neighbors, with local-as201 replace real AS200 so replace-as the role of keywords is: Replace with local AS AS Real in the Updates at The EBGP , translate: when the router secondaryAS the EBGP send updated neighbor, with secondaryAS alternative number Pri aS number. If it is unreachable, the suppression timer is started at the same time. If the timer expires, the same neighbor still advertises the The mask of the destination address. Use set as-path tag to restore, for example, this example on R3 , Router (config) #server dhcp turn on DHCP services. By default, the Cisco IOS DHCP server and relay agent features are enabled on your router To configure globally, use the command: SW3(config)# spanning-tree portfast bpduguard default , which activates bpduguard on all interfaces that activate the portfast feature : IP Address No passive-interface fast 0/24 Optional delivery 16 bits The first 8 bits of the route must be exactly matched with the first 8 bits of 172.0.0.0 . The other bits do not care, and the mask length must be greater than 24. Note that here Although the decision to forward the message is implemented by the FIB , the second layer of frame rewriting is done according to the information in the adjacency list. The second layer needs to be rewritten to include the second layer for frame forwarding. head. For Ethernet, it is the new source, destination MAC , and type field. E.g: Ip prefix-list 2 permit 100.0.2.0/24 route-map WT2 permit 10 Open loopback on R2 , IP is 172.16.10.0/24 , 172.16.11.0/24 Configuration Example 4 (at a single routing protocols -OSPF ) Cause: After the ARP Request is sent , the ARP Reply is prepared for a large number of reasons: scanning on the same network segment (host), scanning across network segments (network device) The origin of the distance vector name is because the route is advertised in the form of a vector (distance, direction), where the distance is defined according to the metric, and the direction is defined according to the next hop router. Next, look at RP , SW2 has two interfaces, both of which will receive BPDUs , all from SW1 , so the cost of the first two BPDUs to root is 0 , equal; the sender ID of the sender is due to the same switch, and therefore equal, less out; and then compare the two BPDU port ID , that is, SW1 on both port interface ID , we assume that the two interfaces equal priority, then the ratio of these two ports The interface ID , and finally select the root port F0/1 on SW2 .