Dynamic routing protocol agreement -RIP
Before discussing the dynamic routing protocol, we might as well talk about the advantages and disadvantages of static routing.
The disadvantage of static routing:
1, the amount of tedious configuration
2, can not automatically change for changes in topology, not immediately update
Static routing advantages:
1, do not take the device and link resources
2, security issues
It is recommended to use a static, large or complex networks in small networks using dynamic routing protocol;
when using dynamic routing protocol, try to update the amount of control to ensure the safety, avoid calculation errors;
So what is a dynamic routing protocol it?
Dynamic routing protocols: an algorithm running on the router so that neighbor (adjacent router) to communicate data between the calculated negotiate to get the unknown network
Dynamic protocol classification:
. 1, the IGP - Interior Gateway Routing Protocol AS within the run
2, EGP - Exterior Gateway Routing Protocol runs between AS
AS-autonomous system (AS: autonomous system in the Internet, an autonomous system (AS. ) is a right to autonomously decide on the routing protocol should be used in the present system, a small unit. this unit can be a simple network of a network may be by one or more common network administrator to control the network groups it is a single manageable network elements (e.g., a university, a business or an individual company) an autonomous system is also sometimes referred to as a routing domain (routing domain). an autonomous system will assign a globally unique 16-bit number, sometimes we put this number is called autonomous system number (ASN))
Standard AS number --0-65535 which 1-64511 private public 64512-65535
IGP - RIP / ISIS / OSPF / EIGRP
IGP protocol classification:
1, based on when the update is carried by the subnet mask to divide ---------- There are categories (not carrying) Classless (carry)
categorical agreement because in the routing information is transmitted, not carry the mask; neighbor it can only be identified by the mask main class of the network segment;
2, based on the characteristics of the work to divide
-DV vector from the RIP / EIGRP
-Ls link status OSPF / ISIS
RIP: the presence of V1 / 2 (IPV4) NG ( IPV6) version Routing Information Protocol
distance vector routing protocol; based UDP520 port work; hop count as the metric;
periodic update ( 30s ) - No ACK acknowledgment mechanism, no keep-alive mechanism + Trigger update (changes in network topology update)
Anti-ring mechanism RIP:
1, horizontal split - from this opening into the mouth does not prevent linear loop topology; MA repeatedly updated network
(PS: MA multiple access network refers to multi-access network, multi-access means in a a plurality of access points on the forward link, different from point to point (P2P) or multipoint (the P2MP) network )
2, poison reverse split horizon - triggered update
3, throttle timer
4, the maximum number of hops - 15 hops
Split Horizon:
When using a distance vector routing protocol, invalid routing information may be propagated, so there will be a routing loop. In other words, if a path has failed, but the router does not know this, it will continue the path advertised as a good path. Using horizontal split resolve this issue is the most common way over a single link. Can be simply understood as: an interface from a subnet to learn from the information is not included in the update of the information issued by the interface.
Toxicity route:
When a path fails, can select a distance vector routing protocols simply stopping the advertised route. In fact, for a router receives a routing update, it is impossible to know whether it is because of router failure, or due to reasons that can not receive a link to the updated routing information, so the introduction of the poison routing to solve the problem.
So that the routing metric poisoning advertise a routing protocol failure path is infinite, it is much like poison reverse, in fact, is a subset of the poison reverse route poisoning. Routing poisoning can be understood as: When a path fails, re-advertise the path metric value is infinite routing information advertised from the previous path interface.
RIP Version:
Difference RIPV1 / V2 are:
1, V1 broadcast multicast update 255.255.255.255 V2 update: 224.0.0.9
2, V1 categorical agreement - no mask V2 classless protocol - carry mask
3, V2 version supports authentication
RIPV1 Configuration
[R1] rip rip start protocol
[r1-rip-1] version Version 1 selected
announcement: RIP can declare interfaces found after the main class ①, to activate - RIP functions can send and receive information
② After excuse, routing thereof pass out information
[-RIP-R1. 1] 1.0.0.0 Network
[-RIP-R1. 1] Network 12.0.0.0
RIPV2 Configuration
[R3] RIP
[-RIP-R3. 1] to select the version Version 2 2
[-RIP-R3. 1] UN Summary must close automatically aggregate, or update the routing, class-based mask
[r3-rip-1] network 23.0.0.0
[r3-rip-1] network 3.0.0.0
Extended configuration:
-
Hand authentication (RIPv2 supported)
on the same directly connected neighbors interface, to ensure updated security
plaintext authentication
[R2] interface G0 / 0/0
[R2-the GigabitEthernet0 / 0/0] RIP authentication-MODE Simple cipher xixi
ciphertext authentication
[ R2] interface G0 / 0/0
[the GigabitEthernet0-R2 / 0/0] MODE RIP-MD5 authentication usual xixi -
Summary manually
configured to update sent on all interfaces on the source router updates
[R2] interface G0 / 0 /. 1
[the GigabitEthernet0-R2 / 0 /. 1] Summary RIP-address 172.16.0.0 255.255.252.0 -
Default Route:
Configure a default instruction border router, the network router will automatically generate a default router of the border point. Flights border router external default route, need to manually configure
[Rl] RIP. 1
[-RIP-Rl. 1] Version 2
[-RIP-Rl. 1] default-route Originate means
Version 1 and version 2 of difference:
1.RIPv1 is like routing protocols, RIPv2 is a classless routing protocol
2.RIPv1 not support VLSM, RIPv2 supports VLSM.
3.RIPv1 no authentication function, RIPv2 supports authentication and clear text and MD5 have two authentication.
4.RIPv1 no manual tabulation function, RIPv2 can be closed automatically aggregate the premise of manual summary.
5.RIPv1 broadcast updates, RIPv2 multicast updates.
6.RIPv1 unmarked routing function, RIPv2 can play tag (tag) for routing, used to filter and make policy.
Update 7.RIPv1 sent can carry up to 25 route entries, RIPv2 can only carry a maximum of 24 routes in the presence of authentication.
8.RIPv1 update packets transmitted there is no next-hop attribute, RIPv2 with a next-hop attribute can be used with the re-routing updates.
to sum up:
The disadvantage of RIP is bad news delivery is slow, but simple, less overhead, relatively safe.
