Upload
norm
View
45
Download
3
Embed Size (px)
DESCRIPTION
Configuring and Verifying Route Redistribution. Implement an IPv4-Based Redistribution Solution. Redistribution Supports All Protocols. Steps to Configure Redistribution into RIP. Enter router RIP configuration mode. R1 (config -router )#. redistribute ospf 1. - PowerPoint PPT Presentation
Citation preview
© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—4-1
Implement an IPv4-Based Redistribution Solution
Configuring and Verifying Route Redistribution
© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—4-2
Redistribution Supports All Protocols
© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—4-3
Steps to Configure Redistribution into RIPEnter router RIP configuration mode
Configure redistribution from another routing protocol; OSPF is used above.
redistribute ospf 1
R1(config-router)#
R1(config-router)# redistribute ospf 1 ? match Redistribution of OSPF routes metric Metric for redistributed routes route-map Route map reference … <cr>
These optional parameters influence redistribution into the RIP routing protocol.
© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—4-4
Redistributing into RIP Redistribute into RIP and assign the metric 3 (3 hops) to all
OSPF routes.
© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—4-5
Steps to Configure Redistribution into OSPFEnter router OSPF configuration mode
Configure redistribution from another routing protocol; EIGRP with AS 10 is used above.
These optional parameters influence redistribution into OSPF routing protocol.
redistribute eigrp 100 metric 100 subnets R1(config-router)#
R1(config-router)# redistribute eigrp 100 ? metric Metric for redistributed routes metric-type OSPF/IS-IS exterior metric type for
redistributed routes route-map Route map reference subnets Consider subnets for redistribution into OSPF tag Set tag for routes redistributed into OSPF … <cr>
© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—4-6
Redistributing into OSPF Redistribute from EIGRP AS 100 into OSPF and change the
metric type from type 2 to type 1.
© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—4-7
Steps to Configure Redistribution into EIGRP Enter router EIGRP configuration mode
Configure redistribution from another routing protocol; OSPF with process number 1 is used above.
These optional parameters influence redistribution into EIGRP routing protocol.
redistribute ospf 1R1(config-router)#
R1(config-router)#redistribute ospf 1 ? match Redistribution of OSPF routes metric Metric for redistributed routes route-map Route map reference …<cr>
© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—4-8
Default Metric
The default metric is set to: Bandwidth in kilobits = 10000, Delay in tens of microseconds = 100, Reliability = 255 (maximum), Load = 1 (minimum), MTU = 1500 bytes
You need to use this command when redistributing from another protocol with incompatible metric into EIGRP.
You do not need this command when redistributing:– static routes to interface or connected networks– between EIGRP processes
R1(config-router)#
default-metric 10000 100 255 1 1500
© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—4-9
Redistributing into EIGRP Redistribute OSPF 1 routing process updates into EIGRP AS 100
and overwrite the default metric.
© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—4-10
Example: Redistributing into OSPF - Before Redistribution
© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—4-11
Example: Configuring Redistribution at Router R2
© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—4-12
Example: Routing Tables After Summarizing Routes and Redistributions
© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—4-13
Route Source Default Distance
Connected interface 0
Static route 1
EIGRP summary route 5External BGP 20
Internal EIGRP 90
IGRP 100
OSPF 110
IS-IS 115
RIPv1, RIPv2 120
ODR 160
External EIGRP 170
Internal BGP 200
Unknown 255
Administrative Distance Administrative distance
(AD) is a way of ranking the trustworthiness of routing information.
A lower administrative distance means a route is more trustworthy.
© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—4-14
Administrative Distance Example From R1 to R6:
– RIP (AD 120) will choose R1-R4-R6– OSPF (AD 110) will choose R1-R2-R3-R5-R6– EIGRP (AD 90) will choose R1-R2-R3-R5-R6
© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—4-15
Steps to Configure Redistribution Using Administrative Distance Enter router configuration mode Configure the redistribution from another routing protocol Modify the administrative distance
– Remember that the configuration is different for different routing protocols
© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—4-16
distance ospf external 100 inter-area 100 intra-area 100R1(config-router)#
Modifying Administrative Distance
Used for OSPF to define the external, interarea, and intra-area distance
Used for EIGRP to define the internal and external distance
Used for BGP to define external, internal, and local distance
distance eigrp 90 170R1(config-router)#
distance bgp 20 200 200R1(config-router)#
© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—4-17
Modifying Administrative Distance (Cont.) The distance eigrp comand is used for EIGRP protocol. The distance (IP) command is protocol-independent
– Used to define an administrative distance for routes that are inserted into the routing table
– Used for all protocols, except for EIGRP, OSPF, and BGP when the dedicated, protocol-specific distance commands are used.
© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—4-18
Modifying Administrative Distance (Cont.) The distance ospf comand is used for OSPF protocol. The distance (IP) command is protocol independent.
– Used to define an administrative distance for routes that are inserted into the routing table.
– Used for all protocols, except for EIGRP, OSPF ,and BGP when the dedicated, protocol-specific distance commands are used.
© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—4-19
Example: Redistribution Using Administrative Distance
© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—4-20
Example: Redistribution Using Administrative Distance (Cont.)
© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—4-21
Example: Redistribution Using Administrative Distance (Cont.)
© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—4-22
Example: Redistribution Using Administrative Distance (Cont.)
© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—4-23
Example: Redistribution Using Administrative Distance (Cont.)
© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—4-24
Simple redistribution results in a loop after a route is lost. To prevent routing loops use route maps with:
– Redistribution of internal routes only– Route tagging
Redistribution to Prevent Routing Loops
© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—4-25
Solution With Route Tagging
© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—4-26
Redistribution With Tagging Verification
Routing table before tagging
© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—4-27
Redistribution With Tagging Verification (Cont.)
Routing table after tagging is applied to router R1
© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—4-28
Summary Redistribution supports all routing protocols. Additionally, static
and connected routes can be redistributed to allow the routing protocol to advertise the routes without using a network statement for them.
Administrative distance (AD) is a way of ranking thetrustworthiness of routing information. A lower administrative distance indicates that a route is more trustworthy.
The distance (IP) command configures the administrative distance per specific network inserted into routing table, regardless of the IP routing protocol used. The specific protocol dependent distance commands are used to define administrative distance for a specific routing protocol.
© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—4-29
Summary (Cont.) Redistribution using administrative distance can correct path
selection problems in a redistribution environment. It is very likely that routing loops are introduced when you use
multipoint two-way redistribution. Two solutions are to redistribute only internal routes and to use route tagging.
The show ip route command output for a specific network shows the tagging values added to a network during the redistribution process.
© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—4-30