To be flourishing on the BSCI communicating and in earning your CCNP, you've got to officer line redistribution. This isn't as cushy as it sounds, because configuring line redistribution is exclusive half the battle. Whether it's on an communicating or in a real-world creation network, you've got to refer doable points of pain before you configure line redistribution - and you requirement to be healthy to curb redistribution as well. You haw hit an OSPF field with 100 routes, but exclusive requirement to redistribute 10 of them into a neighboring RIPv2 domain. You've got to undergo how to do that, and digit method is the ingest of a distribute-list.
A distribute-list is an access-list that is utilised to watch what routes crapper and cannot be redistributed. Distribute-lists accept you take what routes module be filtered from the process. You crapper ingest accepted or long ACLs, and you crapper separate routes that are reaching into a routing impact or existence injected into added process.
In the mass example, R1 is redistributing RIP routes into OSPF, but exclusive wants to promote meshwork 150.1.1.0 /24 to another OSPF routers. An ACL module be cursive to correct that portion network, and then the distribute-list module be cursive low the routing process. I'm feat to exhibit you the IOS Help production for the distribute-list command, and gratify state that routing updates crapper be dominated at the programme take or prescript level.
R1(config)#access-list 24 accept 150.1.1.0 0.0.0.255
R1(config)#router ospf 1
R1(config-router)#redistribute countercurrent subnets
R1(config-router)#distribute-list 24 ?
in Filter inbound routing updates
out Filter outward routing updates
R1(config-router)#distribute-list 11 discover ?
Async Async interface
BRI ISDN Basic Rate Interface
BVI Bridge-Group Virtual Interface
CTunnel CTunnel interface
Dialer Dialer interface
Ethernet IEEE 802.3
Lex Lex interface
Loopback Loopback interface
Multilink Multilink-group interface
Null Null interface
Serial Serial
Tunnel Tunnel interface
Vif PGM Multicast Host interface
Virtual-Template Virtual Template interface
Virtual-TokenRing Virtual TokenRing
bgp Border Gateway Protocol (BGP)
connected Connected
egp Exterior Gateway Protocol (EGP)
eigrp Enhanced Interior Gateway Routing Protocol (EIGRP)
igrp Interior Gateway Routing Protocol (IGRP)
ospf Open Shortest Path First (OSPF)
rip Routing Information Protocol (RIP)
static Static routes
R1(config-router)#distribute-list 11 discover rip
Using distribute-lists does protect against routing loops, but they hit another purposes. You haw hit a meshwork portion that should be kept info from the rest of your company; a distribute-list crapper separate that segment's meshwork sort from the redistribution process. In this way, distribute-lists help as a base modify of meshwork security. (Very basic. I wouldn't delude that firewall on ebay if I were you.)
Keeping much networks discover of routing updates and routing tables throughout the meshwork has the lateral gist of reaction routing update disbursement as well.
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