# Loopback not advertising on R4 from R1
**URL:** https://forum.networklessons.com/t/loopback-not-advertising-on-r4-from-r1/25394
**Category:** BGP
**Created:** [March 24, 2022, 12:29pm UTC](https://forum.networklessons.com/t/loopback-not-advertising-on-r4-from-r1/25394 "2022-03-24T12:29:30Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@salman.saloo93](https://forum.networklessons.com/u/salman.saloo93)
#### Post date: [March 24, 2022, 12:29pm UTC](https://forum.networklessons.com/t/loopback-not-advertising-on-r4-from-r1/25394/1 "2022-03-24T12:29:30Z")
Hey guys, I am currently doing lab with 4 Routers Note: all routers are having same AS number 100
R1 : Loopback 1.1.1.1
R2: Loopback 2.2.2.2
R3: Loopback 3.3.3.3
R4: Loopback 4.4.4.4
So after doing configuration and giving the Neighbors and networks, R1 is not able to ping loopback adr from R4, and R4 is not able to access R1 loopback..
What is wrong i am doing here, while looking into ( Show IP BGP)
```auto
type or paRouter#show ip bgp
BGP table version is 10, local router ID is 13.1.1.1
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight Path
*> 1.1.1.0/24 0.0.0.0 0 32768 i
*>i2.2.2.0/24 12.1.1.2 0 100 0 i
*>i3.3.3.0/24 13.1.1.2 0 100 0 i
* i4.4.4.0/24 34.1.1.2 0 100 0 i
* i 24.1.1.2 0 100 0 i
Router#show ip route
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2
i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static route
o - ODR, P - periodic downloaded static route
Gateway of last resort is not set
1.0.0.0/24 is subnetted, 1 subnets
C 1.1.1.0 is directly connected, Loopback0
2.0.0.0/24 is subnetted, 1 subnets
B 2.2.2.0 [200/0] via 12.1.1.2, 01:23:33
3.0.0.0/24 is subnetted, 1 subnets
B 3.3.3.0 [200/0] via 13.1.1.2, 00:37:41
12.0.0.0/30 is subnetted, 1 subnets
C 12.1.1.0 is directly connected, FastEthernet0/0
13.0.0.0/30 is subnetted, 1 subnets
C 13.1.1.0 is directly connected, FastEthernet0/1
```
The Route is not showing in the routing table
The same is happening from R4… any help would be appreciated!
---
### Author:  [@lagapidis](https://forum.networklessons.com/u/lagapidis)
#### Post date: [March 28, 2022, 4:12am UTC](https://forum.networklessons.com/t/loopback-not-advertising-on-r4-from-r1/25394/2 "2022-03-28T04:12:08Z")
Hello Salman
One of the rules of BGP is that no prefix in the BGP table will be installed into the routing table unless the local router has a valid path to the next-hop IP.
In this particular case, 4.4.4.0/24 has a next-hop IP address of 34.1.1.2. That next-hop IP address has no valid entry in the routing table, therefore the prefix is not installed.
Take a look at this [related NetworkLessons note on the subject](https://notes.networklessons.com/bgp-installing-a-bgp-learned-route-into-the-routing-table).
It seems that routing within AS 100 is not completely configured. Make sure that all routers within the AS are able to reach all other routers, using either an IGP or static routing.
I hope this has been helpful!
Laz