ccnp r&s route
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The processing of the DHCP packet of option82 .
The third column is empty or i . If it is empty, the route is obtained from the EBGP neighbor. The i indicates that this is the route learned from IBGP . The last column indicates the origin of the BGP routing information.
R1 and R3 , R2, and R5 establish an EBGP neighbor relationship.
BGP is a classless routing protocol, a distance vector routing protocol, and automatic summarization is turned off by default (this depends on IOS ).
Learning from other sources, the routing source is incomplete (confirm that the source of the routing information is incomplete). ( Republish IGP or static )
Neighbor 10.1.23.3 local-as 201 [no-prepend] [replace-as] [dual-as]
Preferred to the nearest route to BGP NEXT_HOP 21
Under normal circumstances, the data is preferred to go ip next-hop , that is, go ISP2
Ip route 172.17.0.0 255.255.255.0 192.168.12.1
Is 2 , 3 with AS the first comparison, 2 is MED small it is preferable; 2 with a further comparison, since the opening of the always-compare-med
The default keyword has a lower priority than the detail route.
( FraIue check sequence )
One solution is that SW1 does not insert opiton82 ,ccnp r&s route, another method is to use the configuration on the DHCPserver :
The frame structure formed by the MAC sublayer is mentioned in the introduction above , including IEEE802.3 frames and ETHERNET_II frames.
ip route 172.16.1.0 255.255.255.0 192.168.12.1 !! go subnet route
Originator_ID Cluster_list Weight
Router ospf 100
R1(config)# access-list 1 deny 18.104.22.168 R1(config)# access-list 1 permit any R1(config)# route-map rp permit 10 R1(config-route-map) match ip address 1 R1(config )# router bgp 100
Private VLAN ( PVLAN )
When deploying the campus network, we often have the following special requirements for switches:
The switch sends data frames according to the discovered outbound interface.
SW1(config)# interface vlan 10
Use as-path access-list to match routes
S uppercase S , stale , indicating expired routes
Each routing table entry must include at least the following three items:
When ISP1 is down, and the interface of GW connected to ISP1 is DOWN , the data of PC accessing 100 network is switched to ISP2.
ARP response packets can be sent directly without a request, which leaves a huge loophole for the attacker.
This summary route generated locally is 172.16.0.0/16 , NH=0.0.0.0 , weight= default value 32768 , origin=i . The detail route is marked as " s " and is therefore suppressed.
A BGP neighbor has an impact only on the router. It can be understood as a weight value. The larger the priority, the higher. The value is in the range 0-65535 .
The network segment of the network local direct interface enters BGP , the MED value is 0 ; the network local static route enters BGP , and the MED value is 0.
Protected port can only communicate with unprotected port (default)
Route summary issues to be aware of
The summary of the route is actually done by the operation of the subnet mask. For the following example:
*Mar 1 00:11:48.043: ICMP: echo reply rcvd, src 22.214.171.124, dst 192.168.123.3
Local-pref only affects the amount of traffic leaving the AS ( selecting a large LP value )
Bridge using these 4 steps to save each port received the " best " of the BPDU a copy. When each BPDU arrives, it will check according to this 4- step decision step to see if it has a better BPDU saved on the port . If it is, it will be updated.
Redis static route-map cisco
Router bgp 64512 no synchronization no auto-summary
The configuration of R1 is as follows:
When a router connects through a multi-access medium such as Ethernet, a dynamic mechanism is needed to discover each other, such as ARP . ARP can map Layer 2 addresses to IP . If it is a frame relay multipoint link, the adjacency relationship can be learned by using an address resolution protocol, a mapping table, and the like.
In 802.1D , the TYPE field uses only the highest and lowest bits to indicate TC and TC acknowledgment, and RSTP extends this field:
Redistribution between different OSPF processes
If the MED attribute of a route is lost, the default setting is to set the MED to 0. However, if this command is configured, if the route with no MED value is received , the MED of the route is set to the maximum value of 4294, 9672, 95.
Of course, on R3 , the same effect can be achieved with the distribution list in the in direction.
Activates self-recovery of the err-disable interface due to arp-inspection violations .
A After receiving the response, you know B has established a connection with their locally. A also opens up an SAP value to indicate the connection, and sends a confirmation to B to establish the connection.
When a router is directly connected through a point-to-point link, only one neighbor exists on each interface.
Classification of path attributes:
The requirements, methods and tools for implementing data access path control are often very many. If the basic elements such as IP and VLAN in the early stage of the network are very scientific and reasonable, then it is easier and more diverse to deploy in the strategy. This chapter does not discuss the various path control tools in detail. Just a few common tools and methods are discussed. In fact, using the tools learned in the past , such as route-map, etc.