VRRP (Virtual Router Redundancy Protocol, referred to as VRRP)
Static routing protocol configuration appears to solve the LAN gateway proposed by the IETF single point of failure phenomena, in 1998, it has launched a formal RFC2338 protocol standards. VRRP is widely used in the edge of the network, it's designed to support IP data traffic under certain circumstances failover will not cause confusion, allowing the host to use a single router, and promptly in the case of actual first hop router failure is still able to maintain the router connectivity between.
VRRP is a protocol, it can be the responsibility of a virtual router dynamically allocated to one of the VRRP routers on the LAN. Control VRRP virtual router IP address of the router is called the master router that forwards packets sent to these IP addresses. Once the master fails, this selection process provides a dynamic failover mechanism, which allows a virtual router's IP address as a default host terminal first hop router. LAN access device is a backup protocol. All hosts in a local area network are set to the default gateway, the destination address of such packets is not issued by the host network segment will be sent to the default gateway through three switches, enabling communication of hosts and the external networks.
VRRP is a fault-tolerant routing protocol, also called Standby Routing Protocol. All hosts in a local area network are set to the default route, when the destination address of the internal host network segment is not sent, the packet is default route to the external router, enabling communication with an external network host. When the default router is down (ie the port is closed), internal hosts will not be able to communicate with the outside, if the router is set up VRRP, so this time, virtual routing will enable the backup router, in order to achieve full network communication.
VRRP (Virtual Router Redundancy Protocol, Virtual Router Redundancy Protocol) is a fault-tolerant protocol. Typically, all hosts within a network are set to a default route so that the destination address of the packet is not issued by the host network segment is by default route to Router A router, enabling communication with an external network host. When the router RouterA broken, all on the segment to the default route for the next hop RouterA host single point of failure to cut off communication with the outside. VRRP is to solve the above problems, and it is having a multicast or broadcast multicast capability of LAN (eg: Ethernet) design.
A group of VRRP routers on a LAN (including a Master i.e. active router and several backup routers i.e. Backup) into a virtual router, called a backup group. This virtual router has its own IP address 10.100.10.1 (the IP address and the interface can be the address of a router in the backup group the same, the same is called ip owner), the router in the backup group also has its own IP address (such as IP address for the Master 10.100.10.2, IP address Backup is 10.100.10.3). Host on the LAN only know the IP address 10.100.10.1 of the virtual router, but do not know the specific IP address of the Master router and the IP address of 10.100.10.2 Backup router 10.100.10.3. They own default next-hop address as the IP address 10.100.10.1 of the virtual router. Thus, the host in the LAN communicates with other networks through the virtual router. If the Master router in the backup group is broken, Backup router will elect a new Master router through election strategy, to provide services to hosts on the network. Hosts in the network in order to achieve uninterrupted communication with an external network.
Configuration content:
Spanning Tree-spanning opening (default MSTP) [. 4]
Spanning-Tree Configuration mst mst enters configuration mode
revision 1 is designated MST revision number. 1
name region1 mst configuration name specified
instance 0 vlan 1-9, 11-19 , vlan belong to the default instance 21-4094 0
instance 10 to manually specify a VLAN belonging vlan10 1 example
instance 2 vlan 20 example 2 belonging to manually specify vlan20
priority spanning-tree mst 1 priority 0 1 0 specified instance (the root bridge)
Spanning Tree MST-4096 2 priority specified priority example 2 was 4096
interface of GigabitEthernet 0/1
configuration switchport access vlan 10 g0 / 1 belongs VLAN10
interface of GigabitEthernet 0/2
switchport Access VLAN 20 is arranged g0 / 2 belonging vlan 20! 0/3 of GigabitEthernet interface!
interface of GigabitEthernet 0/24 disposed g0 / 24 is a trunk interface and allows vlan10 / 20 by
! interface VLAN 10 created vlan 10 svi switchport mode trunk interfaces
ip address 192.168.10.1 255.255.255.0 ip address configuration
vrrp 1 priority 120 Configuration group vrrp 1 priority 120
vrrp vrrp 1 ip 192.168.10.254 configuration group 1 virtual ip address 192.168.10.254!
interface VLAN 20 interface to create vlan 20 svi
ip address 192.168.20.1 255.255.255.0 ip address configuration
vrrp ip 192.168.20.254 2 group 2 virtual configuration vrrp ip address is 192.168.20.254
default priority vrrp group 100 not displayed by default!
Line CON 0
Line VTY 0. 4
Login
verify the configuration:
S1 # Show VLAN
the VLAN the Name the Status Ports1 VLAN0001 the STATIC Gi0 /. 3, Gi0 /. 4, Gi0 /. 5, Gi0 /. 6
Gi0 /. 7, Gi0 /. 8, Gi0 /. 9, Gi0 / 10
Gi0 /. 11, Gi0 / 12 is, Gi0 / 13 is, Gi0 / 14
Gi0 / 15, Gi0 / 16, Gi0 /. 17, Gi0 / 18 is
Gi0 /. 19, Gi0 / 20 is, Gi0 / 21 is, Gi0 / 22 is
Gi0 / 23 is, Gi0 / 24
10 VLAN0010 the STATIC Gi0 /. 1, Gi0 / 24
20 is the STATIC VLAN0020 Gi0 / 2, Gi0 / 24
Tracking configuration
general of the gateway uplink interface monitoring, if the joint interface fails, then let out automatically forwarded right configuration object vrrp need to be monitored. Corresponding no command cancels the monitoring of the interface.
Track {group-number VRRP interface-name | Track-ID} [Decrement]
NO VRRP group-number Track interface-name {|} Track ID-
described group-number designated group-number, in the range 1-255.
interface-name specified monitoring interface.
monitored object ID specified track track-id.
Decrement assign priorities to reduce the amplitude. 10 default.
Here also configured in global mode set track
track track-ip intface intface-id line-protocol
Note: After starting the vrrp, we can configure this command.
Border Gateway Protocol (BGP)
routing protocol in a kind of autonomous systems over TCP. BGP is the only protocol that is used to handle the size of the network like the Internet, is the only protocol that can deal well with having multiple connections to unrelated routing domains. BGP builds on the experience of EGP. The main function of the system is BGP and other BGP systems to exchange network reachability information. Network reachability information autonomous system (AS) includes information listed. This information is sufficient to construct a topography of AS connectivity from which routing loops, and can be implemented on the AS-level policy decisions.
Features:
the BGP are external or inter-domain routing protocol. The main objective is to provide a guarantee for BGP routing information in the communication between routers in different AS. Neither purely BGP distance vector protocol, nor a pure link-state protocol, commonly referred to as path vector routing protocol. This is because BGP at the same time accessibility to publish a destination network, contains a list of IP packets to the destination network in the course must pass the AS. When path vector information is useful, because simply look at BGP routing updates AS number can effectively avoid loops. BGP is no restriction on the network topology, characterized by comprising:
(1) up to realize a communication of information between autonomous systems, communication networks. BGP is an external gateway protocol, allowing an AS to communicate with another AS. BGP routing information allowing an AS to advertise its internal network reachability information to other AS, the AS or by other networks reachable. Meanwhile, AS can understand this information from another AS. Similar to distance vector routing protocol, BGP for each destination network is provided next hop (next-hop) node.
(2) a plurality of coordination between BGP routers. If there are multiple routers in the BGP router is used with a series of other autonomous systems communicating peer routers, BGP can coordinator, routers make these consistent routing information within an autonomous system.
(3) BGP supports policy-based routing (policy-base routing). General distance vector routing protocol routing exact routes are advertised in the local. The implementation strategy BGP can be selected by the local administrator. BGP router can be configured as a network reachability between different policy domains and domain.
(4) a reliable transport. BGP routing information transmission using the reliable TCP protocol.
(5) path information. When reachability information for BGP destination network, the destination network designated to the processing of next hop information, advertisement further comprises the vector path (path vector), i.e. the need to go through this destination AS network list, enable the recipient to understand the path information destined for the destination network.
(6) incremental updates. BGP routing updates do not need all the packets transmitted in full routing information database, only a full exchange of information at startup. Subsequent routing updates advertise only change information network. This information network called incremental change (Delta)
(7) BGP support untyped preparation (CIDR) and VLSM way. All are represented in the network advertised network prefix plus the subnet mask of the way.
(8) routing aggregation. BGP allows the sender to gather together the routing information, represented by a plurality of entries associated destination network to save network bandwidth.
(9) BGP also allow the recipient to identify and authenticate packets, to verify the identity of the sender.
BGP route advertisements during the time, we need to follow the following principles:
1, multiple paths, BGP Speaker select only the best for their own use (except for load balancing and FRR).
2, BGP Speaker only the route (optimal route) to advertise their own use of the adjacent body.
3, routing BGP Speaker obtained from EBGP body notices (including EBGP and IBGP) will be adjacent to all of its BGP.
4, BGP Speaker route is not obtained from IBGP (except for reflector) adjacent to their body advertise IBGP.
5, routing BGP Speaker received from IBGP whether advertised to EBGP own body adjacent to decide according to the situation IGP and BGP synchronization.
6, when the refresh messages received on the end of the neighbors and the local support refresh capabilities, BGP Speaker all the BGP routes advertised to the peer.
7, GR during standby switchover party at the end of GR BGP Speaker will all BGP routes advertised to peers.