change AD of specific prefix when readvertising from OSPF to EIGRP

[ChrisPhillips3049]

Hi all.

on a Nexus 7k
I need to change the Administrative Distance of a specific prefix from OSPF so EIGRP table has it at the new AD.
for reasons, we already change the AD of the incoming OSPF routes to 180 so its higher than EIGRP but i have 1 prefix that i need the 7K's to prefer.

simple topology

nx0S-9K1 OSPF <--> OSPF-ad180 nxOS-7K1<-->EIGRP nxOS-7K1<--> EIGRP nxOS-7K2 <--> OSPF-ad180 nxOS-7K2<--> nx0S-9K2 OSPF

example subnet from the 9K = 3.3.3.0/24
OSPF advertises 9k to 7k with AD 110, 7k changes OSPF AD to 180, route then gets redistributed to EIGRP with AD180.




7K ospf config to change distance for all incoming ospf prefix's




router ospf 1
router-id 0.0.0.2
distance 180
passive-interface default
  

examples i have seen suggest that an ACL can be used with the distance command but that is not available on NXOS.

Any suggestions?

[MHM Cisco World · Accepted solution]

1.  configure terminal

2.  router ospf instance-tag

3.  [ no ] table-map map-name

4.  exit

5.  route-map map-name [ permit | deny ] [ seq ]

6.  match route-type route-type

7.  match ip route-source prefix-list name

8.  match ip address prefix-list name

9.  set distance value

this way you can change the AD in nexus for OSPF 

[ChrisPhillips3049 · Accepted solution]

Thanks @MHM Cisco World 

i did initially struggle to get this going as all OSPF routes took that new AD but now all looks ok.

from sh run section test-ospf-eigrp-change-ad:

1. ip prefix-list pl-test-ospf-eigrp-change-ad seq 10 permit 3.3.3.12/32

2. route-map test-ospf-eigrp-change-ad permit 10
   
   match ip address prefix-list pl-test-ospf-eigrp-change-ad
   
   set distance 88

3. router ospf 1
   
   vrf 7k
   
   distance 190
   
   table-map test-ospf-eigrp-change-ad
   
   
   sh ip ro ospf vrf 7k

4. 
   
   3.3.3.12/32, ubest/mbest: 1/0
   *via x.x.x.x, Eth1/x, [88/1], 00:04:48, ospf-1, type-2, tag x
   4.4.4.4/32, ubest/mbest: 1/0
   *via x.x.x.x, Eth1/x, [190/1], 00:04:48, ospf-1, type-2, tag x

Thanks again

[MHM Cisco World]

You are so welcome friend,

Please mention that this issue is solved.