Routing filtering Command Route-map detailed

(i) Route Maps

Characteristics:

The Route maps is similar to access lists, except that Route maps can change some of the properties of the packets/routes.

Use:

Route maps is mainly used for redistribution and Policy Routing and BGP implementation.

Realize:

Policy routing send packets to route maps implement policy Routing forwarding.

Redistribution sends routes to route maps to implement the filtering of the routing entries.

Configuration Description:

Route Maps if the action and Sequence number properties are not specified, the default:

Action:permit

Sequence number:10

And sequence number does not automatically increase.

That is, if sequence number is not specified when the route maps statement is used, the default entry of sequence Number 10 is overwritten.

Route Maps Deny Action:

Redistribution: A specific route entry is not to be distributed.

Policy Routing: A specific packets is not routed by policy, but it will be forwarded in the form of a normal routing table entry.

Case Study:policy Routing

Note: (1) Policy routing only affects incoming flow.

(2) Standard and extended ACLs can be used.

(3) Global configuration IP Local policy route-map sense can apply policy routing to packets sent by router itself.

<1> Standard ACL

Interface Serial 0 IP address 172.16.5.1 255.255.255.0 IP policy route-map sense!access-list 1 Permit 172.16.6.0 0.0.0 .255access-list 2 Permit 172.16.7.0 0.0.0.255!route-map sense permit Match IP address 1 set IP next-hop 172.16.4.2! Route-map sense permit Match IP address 2 set IP next-hop 172.16.4.3
<2> Extended ACL

Interface Ethernet 0 IP address 172.16.1.4 255.255.255.0 IP policy route-map sense!access-list the TCP permit .0 0.0.0.255 eq FTP anyaccess-list permit tcp 172.16.1.0 0.0.0.255 eq ftp-data anyaccess-list the TCP permit. 0 0.0.0.255 eq telnet any!route-map sense permit match IP address set IP next-hop 172.16.2.1!route-map sense PE RMIT match IP address next-hop set IP 172.16.3.1
<3> Length of the Packets

Interface Ethernet0 IP address 172.16.1.4 255.255.255.0 IP policy route-map sense!route-map sense permit match le Ngth 1000 1600 Set IP next-hop 172.16.2.1!route-map sense permit match length 0 set IP next-hop 172.16.3.1
<4> Router ' s Packets

Interface Ethernet0 IP address 172.16.1.4 255.255.255.0 IP policy route-map sense!ip Local policy Route-map Ss-list permit IP any 172.16.1.0 0.0.0.255access-list permit OSPF any ANY!ROUTE-MAP sense permit match IP add Ress sense Permit Match length 1000 1600 set IP next-hop 172.16.2.1!route-map sense permit Match Length 0 Set IP next-hop 172.16.3.1
Note: If there is no first route-map entry, the packets of router itself and the packets of OSPF will be forwarded to the wrong address because of the latter two ROUTE-MAP statements.

Case Study:policy Routing and Quality of service Routing Policy Routing combined with IP header precedence and type of service (TOS) enable QoS based Policy route.

Note: The precedence and TOS can be configured with either the Number field or keyword.

Set IP precedence-------------------------------------Bits     number     Keyword000     &N Bsp  0        routine001        1        priority010   & nbsp    2        immediate011        3        flash100 &N Bsp      4        flash-override101        5       &NBSP ; critical110        6        internet111        7   &NBSP ;    network-------------------------------------set IP tos-------------------------------------Bits     number     Keyword0000       0        normal0001       1        min-monetary-cost0010       2        max-reliabilit y0100      4        max-throughput1000       8        min-delay-------- -----------------------------interface Serial0   IP address 10.1.18.67 255.255.255.252   IP policy route-map SE Nse!interface Serial1   IP address 10.34.16.83.255.255.255.252   IP policy route-map sense!access-list 1 Permit 172.16.0.0 0.0.255.255access-list permit tcp any eq www any!route-map sense permit   match IP address 1 &n Bsp Set IP precedence critical!route-map sense permit   set IP TOS ten   set IP precedence prioritycase Study:rou Te Tagging