Routing questions

[anthony.dyne]

Hi

I got Two questions

(1)  In Mutual Redistribution why this command needed  "redistribute ospf 5 match internal external 1 external 2" why not only

"redistribute ospf 5 subnets" is enough??

(2)  X-----------------------Y

       |                               |

       |                               |

    000--------ZZ--------000

X connects to Y metro network 35MB

X connects to Z on MPLS could 1MB

Y connect to Z on MPLS cloud 1MB

X  reaches Y via XY metro link

when Link Y to ZZ is up then Y prefers YZZ(MPLS Link) to reach X

MPLS is over BGP

metro link is over OSPF

LAN is runnning OSP

Any suggestion

cheers

Anthony

[kyukim]

Hi,

It is special requirement between ospf and bgp.

If you configure the redistribution of OSPF into BGP without keywords, by only OSPF intra-area and inter-area routes are redistributed into BGP, by default.

Below document provides more detail.

http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a00800943c5.shtml

KK.

[anthony.dyne]

Hi kim

question One is clear.  any suggestion on question Two

Thanks

[kyukim]

Hi, Anthony.

For Q2, it is up to AD (admin distance) of routes that Y learns from MPLS link or Metro link.

eBGP AD is 20

OSPF AD is 110

iBGP AD is 200

if Y has eBPG peer with Z from mpls link, then it will always prefer eBGP routes it learns from Z.

You can change AD of eBGP by "bgp distance 111" under router bgp x. This will make Y prefers routes learned from OSPF.

KK.