Route redistribution

[fx_33]

Hello, I am facing issues regarding connectivity as I am fairly new to BGP and route redistribution.

In my topology there are 3 autonomous systems with eBGP running between them, each AS is running iBGP and a different IGP. I am trying to redistribute these IGP routes into eBGP so that there can be reachability between sites, however redistribution is not working correctly.

AS 1003 is running IS-IS and AS 1004 is running EIGRP.
Routers P3 (AS 1004) and PE-2 (AS 1004) are directly connected and running eBGP and are redistributing their IGP routes into BGP but despite this they don't have reachability with other routers. AS 1003 routers can't ping 1004 routers and vice versa

Here is the configuration on PE-2:

PE-2#
ip router isis BBK_KW
ip router isis BBK_KW
router isis BBK_KW
net 49.0001.0000.0000.000a.00
redistribute bgp 1003 metric 30 level-1-2

PE-2#

router bgp 1003
bgp router-id 1.1.1.22
bgp log-neighbor-changes
no bgp default ipv4-unicast
neighbor 203.0.113.2 remote-as 1005
neighbor 203.0.113.10 remote-as 1004
neighbor 203.0.113.30 remote-as 1003
neighbor 203.0.113.34 remote-as 1003
neighbor 203.0.113.73 remote-as 1005
neighbor 203.0.113.82 remote-as 1004
!
address-family ipv4
bgp redistribute-internal
network 1.1.1.22 mask 255.255.255.255
network 209.1.1.22 mask 255.255.255.255
redistribute isis BBK_KW level-1-2 metric 50
neighbor 203.0.113.2 activate
neighbor 203.0.113.10 activate
neighbor 203.0.113.30 activate
neighbor 203.0.113.34 activate
neighbor 203.0.113.73 activate
neighbor 203.0.113.82 activate
exit-address-family

Here is the configuration on P3:
P3#
router eigrp BBK_UAE
!
address-family ipv4 unicast autonomous-system 1004
!
topology base
redistribute bgp 1004 metric 65 1000 255 1 1500
exit-af-topology
network 3.3.3.3 0.0.0.0
network 192.3.3.3 0.0.0.0
network 203.0.113.48 0.0.0.3
network 203.0.113.52 0.0.0.3
eigrp router-id 3.3.3.3
exit-address-family

P3#
router bgp 1004
bgp router-id 3.3.3.3
bgp log-neighbor-changes
no bgp default ipv4-unicast
neighbor 203.0.113.9 remote-as 1003
neighbor 203.0.113.18 remote-as 1005
neighbor 203.0.113.50 remote-as 1004
neighbor 203.0.113.54 remote-as 1004
neighbor 203.0.113.77 remote-as 1005
neighbor 203.0.113.81 remote-as 1003
!
address-family ipv4
bgp redistribute-internal
network 3.3.3.3 mask 255.255.255.255
network 192.3.3.3 mask 255.255.255.255
redistribute eigrp 1004 metric 65
neighbor 203.0.113.9 activate
neighbor 203.0.113.18 activate
neighbor 203.0.113.50 activate
neighbor 203.0.113.54 activate
neighbor 203.0.113.77 activate
neighbor 203.0.113.81 activate
exit-address-family

If anybody knows what the issue is I would greatly appreciate your help

[paul driver]

Hello

---

@fx_33 wrote:

AS 1003 is running IS-IS and AS 1004 is running EIGRP.
Routers P3 (AS 1004) and PE-2 (AS 1004)

Those are running different bgp ASNS but you state they are running the same

If they are running the ASNs then by the sounds of it you will have dual mutual redistribution points PE2- P3 in AS1004 which would possible create some route feedback, between the routing process , I suggest then in this case apply to route filters to negate any possibility of this.

Example: rtrs PE2-P3

route-map BGP-into-IGP deny 10
match tag 179

route-map BGP-into-IGP permit 100
set tag 179

router eigrp BBK_UAE
address-family ipv4 unicast autonomous-system 1004
topology base
redistribute bgp 1004 metric 65 1000 255 1 1500 route-map BGP-into-IGP

router isis BBK_KW
net 49.0001.0000.0000.000a.00
redistribute bgp 1004 metric 30 level-1-2  route-map BGP-into-IGP 

[MHM Cisco World]

The BGP make both PE have prefix in it table but 

The traffic is drop in P

You need to data traffic bypass P by using 

A- mpls

B- GRE tunnel 

Or config ebgp between PE and P (this not recommend)

MHM