understanding bgp

These days have been looking at BGP, I think the attribute of BGP is a difficult point, sometimes look at to their own are confused, especially the difference between LOCAL-PREF and MED in BGP. after finding some information on the Internet, I can understand a lot. Med is used to affect the inbound traffic. It is an announcement to the ebgp peer.The local-pref i

C through the BGP learning, will generate a routing table based on the shortest path algorithm to select the path of a more optimal service-side address assume a more excellent New route Table 10.0.0.1--192.168.1.3. In the process of use, the BGP network will continue to send each other keeplive packets if C to send a packet result of failure is a down, then C will delete the route table 10.0.0.1--192.168.

To allow OSPF routing features to pass through the mpls vpn backbone network, some BGP extended group attributes need to be defined. OSPF attributes that can be passed through mp bgp include: 650) this. width = 650; "border =" 0 "alt =" "src =" http://www.bkjia.com/uploads/allimg/131227/0201221933-0.jpg "/> The extended attribute of mp bgp allows OSPF routes to b

exists in a route, the RR will not create a new originator_id. (2) When other BGP speaker receive this route, they will compare the received originator_id and the local Router ID, if two IDs are the same, BGP speaker ignores this route and does not process it. The Originator_id property guarantees that the route does not loop between the reflector and the client/non client. Cluster_list is a 4 8-bit op

A key problem statement (a) How does the ACL match the same subnet and the different mask routing entries? How do I match the same mask, different entries for subnets? (ii) Why does a summary route cause the rollover of a BGP neighbor? (iii) Why does the ACL not match the route entry when using Attribite-map? (d) How to use Advertise-map,suppress-map,unsuppress-map,attribute-map and Route-map five-way map? Give an example. (v) The two schemes of

Topology: Configuration: --------------------------R1------------------------ Interface Loopback0IP Address 1.1.1.1 255.255.255.0!Interface fastethernet0/0IP address 12.1.1.1 255.255.255.0Duplex AutoSpeed autoRouter BGP 100No synchronizationBGP Router-id 1.1.1.1BGP log-neighbor-changesNetwork 1.1.1.0 Mask 255.255.255.0Neighbor 12.1.1.2 Remote-as 200No auto-summary --------------------------R2--------------- Interface Loopback0IP address 2.2.2.2

Today, we gave a client a test report based on Route-map to filter through different routes to different end-to-end Cross-domain neighbors. The function point is very small, but for the junior students want to help. BGP is actually a very powerful routing protocol for routing filtering. CCIE is also the focus of the exam, in fact, there is a very good book to recommend to everyone: Hope to be useful to the beginner

Absrtact: Broadband IP metropolitan Area network, routing planning and design is the core link. In the beginning of the network, must be integrated planning. According to the construction of the metropolitan area Network, the routing strategy based on Bgp/mpls VPN is adopted, which is proved to be feasible by practice. Key words: BGP MPLS VPN IP Routing strategy 1 Broadband metropolitan Area Network overv

BGP routing is optimal, in the absence of filtering, there are two conditions related: Next hop can be reached, synchronous shutdown. If these two conditions are not met, the routing is not optimal.BGP Routing principle: If the next hop of this route is unreachable, this route is ignored Preferred-valnue value higher priority, Huawei Private attribute, only local meaningful Local-preference highest-Value routing priority Aggregation rou

Background: two lines used by our company, one of which is the MPLS line of China Telecom. We need to transmit the routes to the BGP Route of China Telecom, the BGP routing protocol of China Telecom is transmitted to the corresponding routing table of the headquarters.Symptom:Suddenly, the MPLS line of China Telecom was disconnected, and Netcare called to report the fault. I thought the optical fiber was di

650) this.width=650; "title=" 1.jpg "src=" Http://s2.51cto.com/wyfs02/M02/7D/68/wKiom1bnqi6AS7ZEAACL5nzpsow254.jpg " alt= "Wkiom1bnqi6as7zeaacl5nzpsow254.jpg"/>This experiment is derived from the HCNP routing experiment GuideExperimental requirements: 1. AS200 cannot receive routes from other branch offices2. Branch Office 2 (AS300) cannot advertise its own routing information to other branch offices3. Branch Office 4 (AS500) cannot receive routing for branch Office 3 (AS400)Experimental address

Summary of configuration formats of dynamic routing (ripV2, ospf, VPN, bgp, IS-IS)1. r12002router rip enable rip Protocol no atuo-summary disable automatic summary of version 2 2 network x mask x declaring the network segment (the subnet mask is a positive mask, mask can be disabled. 2. Enable the ospf protocol for ospfrouter ospf x, and add the Process Code router-id x to specify the router-id (the address must be ipv4) network x mask x area x declar

generate the most reasonable path (merge ). (The basic logic of RIP is: if A is 6 away from B and I am 1 Away From A, the distance from A to B is 7) For technical reasons (looping hops), rip considers that IP addresses over 15 cannot arrive. Therefore, rip is more used in the Internet (such as the entire China Telecom Network ). Such an internet part often belongs to the same ISP or has the same management organization, so it is called an autonomous system (as, autonomous system ). Hosts and

Use BGP when one of the following conditions exists ----- As allows data packets to pass through it to other self-made Systems Multiple external connections, multiple carriers, and multiple Internet connections You must control the inbound and outbound data streams. BGP is not used when the following conditions exist: Connect only to the as or Internet When the vro memory and CPU performance is poor

《 BGP routing policies in ISP Networks " IEEE Network magazine 2005 1 Ways to configure local policythere are three classes of "knobs" that can be used to controlimport and export policies: 1) preference (demo-process) 2) filter (eliminate certain route) 3) tag (community) 2 BGP policy common practice and design pattern1) business relationship (1) inbound: Assign local-preference to influence the

The problems that arise: A) R1 has a 7.7.7.0/24 route on it, but Ping 7.7.7.7 is not reached. (R7 same) Now view the R1 routing table R7#sh IP route B 1.1.1.0 [20/0] via 5.5.5.5, 00:02:54/To save space incomplete display It can be seen that R7 learned the route of the R1, from the surface to see the experiment is perfect, for the purpose, but then the problem arises, make a test, on the R7 ping R1 R7#ping 1.1.1.1 Type escape sequence to abort. Sending 5, 0-byte ICMP Echos to 7.7.7.7, tim

Release date:Updated on: Affected Systems:Quagga Description:--------------------------------------------------------------------------------Cve id: CVE-2012-0255 Quagga is a route software suite that can implement multiple routing protocols on Unix platforms. Quagga 0.99.20.1 when implementing BGP, ospfd does not correctly use messages for OPEN messages, resulting in DOS through messages related to malformed AS4 functions. Link: http://secunia.co

TCP/IP Note 2. Network Layer (2) -- ICMP, RIP, OSPF, BGP 1. ICMPICMP (Internet Control Message Protocol): improves the chances of successful IP datagram delivery. 1.1 features ICMP allows the host or router to report errors and reports exceptions. ICMP is not a high-level protocol, but an IP layer protocol. An ICMP packet is used as the data of an IP-layer datagram, And the header of the datagram is added to send an IP datagram. 1.2 format 1.3 packet

Border GatewayProtocol is a routing protocol that dynamically exchanges route information between autonomous systems. A classic definition of an autonomous system is a group of routers under the control of a management organization. It uses IGP and common measurement values to forward packets to other autonomous systems. The term autonomous systems are used in BGP to emphasize the fact that the management of an autonomous system provides a unified in

1. If the next hop cannot be reached, do not consider2. Select a route with the maximum weight.3. If the route has the same weight, use the route with the highest local priority.4. If you have the same local priority, the BGP Route from the vrobgp is preferred.5. If there is no BGP Route from the vrobgp, select the route with the shortest AS length.6. If all the routes have the same AS length, select the ro