BGP and EIGRP redistribution

[tinhnho123]

Hi Everyone,

On my production router, I have this setup:

```
prod_router#sh run | Sec router
router eigrp PROD
!
address-family ipv4 unicast autonomous-system 101
!
topology base
redistribute connected
redistribute static metric 10000 10 255 255 150 route-map static-to-eigrp
redistribute bgp 65001 metric 100 1 255 1 1500
exit-af-topology
network 10.19.3.0 0.0.0.255
exit-address-family
!

router bgp 65001
bgp log-neighbor-changes
neighbor 192.65.0.13 remote-as 3549
neighbor 192.65.0.13 version 4
neighbor 192.65.0.13 timers 5 15
!
address-family ipv4
network 10.19.3.0 mask 255.255.255.0
redistribute eigrp 101 metric 100 route-map eigrp-to-bgp
neighbor 192.65.0.13 activate
neighbor 192.65.0.13 next-hop-self
exit-address-family
!
prod_router#sh run | sec ip route
ip route 172.16.5.0 255.255.255.0 172.19.3.1 200
ip route 172.16.6.0 255.255.255.0 172.19.3.1 200
prod_router#

route-map static-to-eigrp permit 10
match ip address static-to-eigrp

route-map eigrp-to-bgp permit 10
match ip address eigrp-to-bgp

ip access-list standard static-to-eigrp
10 deny any

ip access-list extended eigrp-to-bgp
10 permit ip 10.19.3.0 0.0.0.255 any
20 permit ip any any
```

I have a couple questions:
1. What are these lines exactly meant? please explain in a plain English if possible!

```
redistribute static metric 10000 10 255 255 150 route-map static-to-eigrp
redistribute bgp 65001 metric 100 1 255 1 1500
redistribute eigrp 101 metric 100 route-map eigrp-to-bgp
```
2. Regarding route-map of 'redistribute static metric 10000 10 255 255 150 route-map static-to-eigrp'.
```
route-map static-to-eigrp permit 10
match ip address static-to-eigrp
ip access-list standard static-to-eigrp
10 deny any
```

If the 'static-to-eigrp' ACL is denying all, why do we need to redistribute static in to eigrp?

Thanks!

[MHM Cisco World]

I will divide your Q into two part 
I start with route-map and deny ACL 
this not effect NOT action as table below if the ACL deny and route-map is permit. 
so I think this mistake. 

[tinhnho123]

Just so I understand, from this command 'redistribute static metric 10000 10 255 255 150 route-map static-to-eigrp', the route-map static-to-eigrp' is no use and I can remove it?

Thanks.

[Harold Ritter]

Hi @tinhnho123 ,

That is correct. No static route will ever be redistributed in eigrp in this context. If this is what you want, it is safe to remove this command from your configuration. Otherwise, modify the route-map to match your requirement.

Regards,

[tinhnho123]

Thanks! I'll remove this line 'redistribute static metric 10000 10 255 255 150 route-map static-to-eigrp'

I'm confused about the commands below. By any chance, do you know what these lines below exactly meant in this case? 

redistribute bgp 65001 metric 100 1 255 1 1500
redistribute eigrp 101 metric 100 route-map eigrp-to-bgp

Those metric and numbers are driving me crazy

Thanks.

[Harold Ritter]

Hi @tinhnho123 ,

Here's an excerpt from documentation explaining the 5 metrics needed when redistributing into eigrp.

As for the eigrp redistribution into bgp, the metric is simply being set to 100.

Regards,

[tinhnho123]

Hi Harold,

"As for the eigrp redistribution into bgp, the metric is being to 100."

what does this number '100' represent in this linee 'redistribute eigrp 101 metric 100 route-map eigrp-to-bgp'?

Thanks!

[MHM Cisco World]

OK, 
we are here dealing with two routing protocol, 
we play with two value to make path high prefer or less prefer, 
the value that we can play with BW and delay, 
MTU and reliability and load is always same, 
so it depend on. 

[MHM Cisco World]

I will run small lab show the effect of the delay metric with redistribute.

[Harold Ritter]

Hi @tinhnho123 ,

The metric in the bgp context is what is called Multiple Exit Discriminator (MED). Refer to the following document for more information about the BGP MED attribute.

https://www.cisco.com/c/en/us/support/docs/ip/border-gateway-protocol-bgp/13759-37.html

Regards,

[MHM Cisco World]

wait here,
I mention that this route-map is mistake i.e. NO ACTION and the route-map will check second line which you not config it and hence no static route is redistribute into EIGRP
you can remove it if you sure you not need it.