Routing
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Routing

iBGP Hidden Routes

‎10-22-2019 07:42 AM

Hi,

 

Having trouble getting the hidden routes within our iBGP routers. Anyone can help? Really appreciate it.

 

Current situation:

R1 is advertising the external routes it gets from eBGP peers to R2 via iBGP, R2 is getting it and able to advertise it to its eBGP peer.

 

R2 is advertising the external routes it gets from eBGP peers to R1 via iBGP but R1 is only seeing the routes as hidden routes.

 

Also, compared to the routes that R2 receives from R1 via iBGP, we're seeing that routes received by R1 from R2 via iBGP has (Looped: xxxxx) in the logs, anyone knows the reason for this?

=================================================

R1 config and output:

 

> show route receive-protocol bgp 116.93.59.2

inet.0: 31160 destinations, 37694 routes (31153 active, 0 holddown, 7 hidden)
Restart Complete

 

> show route receive-protocol bgp 116.93.59.2 hidden

inet.0: 31160 destinations, 37694 routes (31153 active, 0 holddown, 7 hidden)
Restart Complete
Prefix Nexthop MED Lclpref AS path
116.93.45.0/24 121.127.0.206 20 110 23930 I
116.93.86.0/24 121.127.0.206 110 23930 I
116.93.99.0/24 121.127.0.206 110 23930 I
116.93.126.0/24 121.127.0.206 110 23930 I
121.127.0.0/24 121.127.0.206 110 23930 I
121.127.1.0/24 121.127.0.206 110 23930 I
203.208.24.0/24 121.127.0.206 20 110 23930 I

 

> show route receive-protocol bgp 116.93.59.2 hidden detail table inet.0

inet.0: 31160 destinations, 37694 routes (31153 active, 0 holddown, 7 hidden)
Restart Complete
116.93.45.0/24 (1 entry, 0 announced)
Nexthop: 121.127.0.206
MED: 20
Localpref: 110
AS path: 23930 I (Looped: 23930)
Communities: no-export

116.93.86.0/24 (1 entry, 0 announced)
Nexthop: 121.127.0.206
Localpref: 110
AS path: 23930 I (Looped: 23930)
Aggregator: 23930 121.127.1.245
Communities: no-export

116.93.99.0/24 (1 entry, 0 announced)
Nexthop: 121.127.0.206
Localpref: 110
AS path: 23930 I (Looped: 23930)
Aggregator: 23930 121.127.1.245
Communities: no-export

116.93.126.0/24 (1 entry, 0 announced)
Nexthop: 121.127.0.206
Localpref: 110
AS path: 23930 I (Looped: 23930)
Aggregator: 23930 121.127.1.245
Communities: no-export

121.127.0.0/24 (1 entry, 0 announced)
Nexthop: 121.127.0.206
Localpref: 110
AS path: 23930 I (Looped: 23930)
Aggregator: 23930 121.127.1.240
Communities: no-export

121.127.1.0/24 (1 entry, 0 announced)
Nexthop: 121.127.0.206
Localpref: 110
AS path: 23930 I (Looped: 23930)
Aggregator: 23930 121.127.1.240
Communities: no-export

203.208.24.0/24 (1 entry, 0 announced)
Nexthop: 121.127.0.206
MED: 20
Localpref: 110
AS path: 23930 I (Looped: 23930)
Communities: no-export

 

> show bgp neighbor 116.93.59.2
Peer: 116.93.59.2+179 AS 132209 Local: 116.93.59.1+58622 AS 132209
Description: IPC_CH_ASN_Rho-Sigma
Type: Internal State: Established Flags: <Sync>
Last State: OpenConfirm Last Event: RecvKeepAlive
Last Error: None
Import: [ IBGP-import ]
Options: <Preference LocalAddress GracefulRestart PeerAS Multipath LocalAS Refresh>
Local Address: 116.93.59.1 Holdtime: 90 Preference: 170 Local AS: 132209 Local System AS: 132209
Number of flaps: 1
Last flap event: RecvNotify
Error: 'Hold Timer Expired Error' Sent: 0 Recv: 1
Peer ID: 116.93.59.2 Local ID: 116.93.59.1 Active Holdtime: 90
Keepalive Interval: 30 Peer index: 0
BFD: disabled, down
NLRI for restart configured on peer: inet-unicast
NLRI advertised by peer: inet-unicast
NLRI for this session: inet-unicast
Peer supports Refresh capability (2)
Restart time configured on the peer: 120
Stale routes from peer are kept for: 300
Restart time requested by this peer: 120
NLRI that peer supports restart for: inet-unicast
NLRI peer can save forwarding state: inet-unicast
NLRI that peer saved forwarding for: inet-unicast
NLRI that restart is negotiated for: inet-unicast
NLRI of received end-of-rib markers: inet-unicast
NLRI of all end-of-rib markers sent: inet-unicast
Peer supports 4 byte AS extension (peer-as 132209)
Peer does not support Addpath
Table inet.0 Bit: 10000
RIB State: BGP restart is complete
Send state: in sync
Active prefixes: 0
Received prefixes: 7
Accepted prefixes: 0
Suppressed due to damping: 0
Advertised prefixes: 31118
Last traffic (seconds): Received 12 Sent 5 Checked 6
Input messages: Total 405961 Updates 55 Refreshes 0 Octets 7715620
Output messages: Total 418925 Updates 13034 Refreshes 0 Octets 9002938
Output Queue[0]: 0

{master}

 

> show configuration policy-options policy-statement IBGP-import
term anything-else {
then accept;

}

 

> show configuration protocols bgp group IPC_CH_ASN_IBGP
type internal;
local-address 116.93.59.1;
import IBGP-import;
peer-as 132209;
local-as 132209;
graceful-restart;
multipath;
neighbor 116.93.59.2 {
description IPC_CH_ASN_Rho-Sigma;

> show configuration routing-options autonomous-system

132209;

 

 

=================================================

R2 config and output:

 

> show route advertising-protocol bgp 116.93.59.1

inet.0: 31148 destinations, 31148 routes (31148 active, 0 holddown, 0 hidden)
Restart Complete
Prefix Nexthop MED Lclpref AS path
* 116.93.45.0/24 121.127.0.206 20 110 23930 I
* 116.93.86.0/24 121.127.0.206 110 23930 I
* 116.93.99.0/24 121.127.0.206 110 23930 I
* 116.93.126.0/24 121.127.0.206 110 23930 I
* 121.127.0.0/24 121.127.0.206 110 23930 I
* 121.127.1.0/24 121.127.0.206 110 23930 I
* 203.208.24.0/24 121.127.0.206 20 110 23930 I

{master}
> show bgp neighbor 116.93.59.1
Peer: 116.93.59.1+58622 AS 132209 Local: 116.93.59.2+179 AS 132209
Description: IPC_CH_ASN_Sigma-Rho
Type: Internal State: Established Flags: <Sync>
Last State: OpenConfirm Last Event: RecvKeepAlive
Last Error: Hold Timer Expired Error
Import: [ IBGP-import ]
Options: <Preference LocalAddress GracefulRestart Damping PeerAS Multipath LocalAS Refresh>
Local Address: 116.93.59.2 Holdtime: 90 Preference: 170 Local AS: 132209 Local System AS: 132209
Number of flaps: 1
Last flap event: HoldTime
Error: 'Hold Timer Expired Error' Sent: 1 Recv: 0
Peer ID: 116.93.59.1 Local ID: 116.93.59.2 Active Holdtime: 90
Keepalive Interval: 30 Peer index: 0
BFD: disabled, down
NLRI for restart configured on peer: inet-unicast
NLRI advertised by peer: inet-unicast
NLRI for this session: inet-unicast
Peer supports Refresh capability (2)
Restart time configured on the peer: 120
Stale routes from peer are kept for: 300
Restart time requested by this peer: 120
NLRI that peer supports restart for: inet-unicast
NLRI peer can save forwarding state: inet-unicast
NLRI that peer saved forwarding for: inet-unicast
NLRI that restart is negotiated for: inet-unicast
NLRI of received end-of-rib markers: inet-unicast
NLRI of all end-of-rib markers sent: inet-unicast
Peer supports 4 byte AS extension (peer-as 132209)
Table inet.0 Bit: 50000
RIB State: BGP restart is complete
Send state: in sync
Active prefixes: 31118
Received prefixes: 31118
Accepted prefixes: 31118
Suppressed due to damping: 0
Advertised prefixes: 7
Last traffic (seconds): Received 25 Sent 3 Checked 44
Input messages: Total 166109 Updates 9654 Refreshes 0 Octets 4022529
Output messages: Total 156549 Updates 53 Refreshes 0 Octets 2976849
Output Queue[4]: 0


> show configuration policy-options policy-statement IBGP-import
term anything-else {
then accept;
}

 

> show configuration protocols bgp group IPC_CH_ASN_IBGP
type internal;
local-address 116.93.59.2;
import IBGP-import;
inactive: export IBGP-export;
peer-as 132209;
local-as 132209;
graceful-restart;
multipath;
neighbor 116.93.59.1 {
description IPC_CH_ASN_Sigma-Rho;

 

> show configuration routing-options autonomous-system

132209;

 

> show route receive-protocol bgp 116.93.59.1 table inet.0 detail

inet.0: 31149 destinations, 31149 routes (31149 active, 0 holddown, 0 hidden)
Restart Complete
* 1.1.8.0/24 (1 entry, 1 announced)
Accepted
Nexthop: 63.140.5.57
Localpref: 100
AS path: 4809 4134 I
AS path: Recorded
Communities: 4134:20252

* 1.1.8.0/25 (1 entry, 1 announced)
Accepted
Nexthop: 63.140.5.57
Localpref: 100
AS path: 4809 4134 58543 I
AS path: Recorded
Communities: 4134:20252

* 1.1.8.128/25 (1 entry, 1 announced)
Accepted
Nexthop: 63.140.5.57
Localpref: 100
AS path: 4809 4134 58543 I
AS path: Recorded
Communities: 4134:20252

* 1.2.4.0/24 (1 entry, 1 announced)
Accepted
Nexthop: 219.158.39.33
Localpref: 100
AS path: 4837 4808 24151 I
AS path: Recorded

* 1.18.128.0/24 (1 entry, 1 announced)
Accepted
Nexthop: 63.140.5.57
Localpref: 100
AS path: 4809 4134 4847 24151 23596 I
AS path: Recorded
Communities: 4134:20052

* 1.24.0.0/13 (1 entry, 1 announced)
Accepted
Nexthop: 219.158.39.33
Localpref: 100
AS path: 4837 I (Atomic) Aggregator: 4837 219.158.1.45
AS path:
AS path: Recorded

* 1.24.32.0/22 (1 entry, 1 announced)
Accepted
Nexthop: 219.158.39.33
Localpref: 100
AS path: 4837 139007 I
AS path: Recorded

* 1.24.36.0/22 (1 entry, 1 announced)
Accepted
Nexthop: 219.158.39.33
Localpref: 100
AS path: 4837 139007 I
AS path: Recorded

* 1.24.80.0/22 (1 entry, 1 announced)
Accepted
---(more)---[abort]

{master}

 

=================================================

 

 

 

Thanks!

7 REPLIES 7
Highlighted
Routing

Re: iBGP Hidden Routes

‎10-22-2019 08:25 AM

Hi,

 

Few things:

1. For IBGP, you always need Next-hop Self policy in your export policy. It's missing here on both R1 and R2

 

2. Can you also provide the configs for your EBGP session on R1 and R2? 

 

3. Get this output on R2

>show route receive-protocol bgp <ebgp peer>


Mengzhe Hu
JNCIE x 3 (SP DC ENT)
Highlighted
Routing

Re: iBGP Hidden Routes

‎10-22-2019 08:28 AM

Hi,

Do you have "local-as 23930" configured for any other BGP peer on R1? Can you please provide the output of - 

show configuration | match 23930 | display set

show as-path domain

To install the route from R2 try the "loops" knob.

<..>

local-address 116.93.59.1;
import IBGP-import;
peer-as 132209;
local-as 132209 loops 2;
graceful-restart;
multipath;
neighbor 116.93.59.2

<..>

 

*** Please mark the reply as solution if it resolves the issue so others can benefit from the post

Highlighted
Routing

Re: iBGP Hidden Routes

‎10-22-2019 08:29 AM

R2 is advertising EBGP routes with NH 121.127.0.206, seems it's not available on R1? Things might be different on the other direction.

 

However, best practice for IBGP is to have NHS

set protocol bgp group ibgp export nhs 

set policy-options policy-statement nhs term 1 then next-hop self


Mengzhe Hu
JNCIE x 3 (SP DC ENT)
Highlighted
Routing

Re: iBGP Hidden Routes

‎10-22-2019 08:31 AM

Hello,


saul.cabangcalan@ipc.ph wrote:

Hi,

 

Having trouble getting the hidden routes within our iBGP routers. Anyone can help? Really appreciate it.

 

Current situation:

R1 is advertising the external routes it gets from eBGP peers to R2 via iBGP, R2 is getting it and able to advertise it to its eBGP peer.

 

R2 is advertising the external routes it gets from eBGP peers to R1 via iBGP but R1 is only seeing the routes as hidden routes.

 

Also, compared to the routes that R2 receives from R1 via iBGP, we're seeing that routes received by R1 from R2 via iBGP has (Looped: xxxxx) in the logs, anyone knows the reason for this?

=================================================

<skip>

> show route receive-protocol bgp 116.93.59.2 hidden detail table inet.0

inet.0: 31160 destinations, 37694 routes (31153 active, 0 holddown, 7 hidden)
Restart Complete
116.93.45.0/24 (1 entry, 0 announced)
Nexthop: 121.127.0.206
MED: 20
Localpref: 110
AS path: 23930 I (Looped: 23930)
Communities: no-export

 


 

 

JUNOS does the AS_PATH loop check for all and any of the ASNs configured on the box including all VRFs, virtual routers and  Logical Systems, and including those ASNs in "local-as" knobs.

Check if You have "autonomous-system 23930" or "local-as 23930" line in Your R1 config, look under all VRFs/VRs/LS.

If You have and cannot take it away, configure "independent-domain" to switch off this AS_PATH loop check for a particular VRF/VR/LS https://www.juniper.net/documentation/en_US/junos/topics/reference/configuration-statement/independe...

HTH

Thx

Alex

 

 

_____________________________________________________________________

Please ask Your Juniper account team about Juniper Professional Services offerings.
Juniper PS can design, test & build the network/part of the network as per Your requirements

+++++++++++++++++++++++++++++++++++++++++++++

Accept as Solution = cool !
Accept as Solution+Kudo = You are a Star !
Highlighted
Routing

Re: iBGP Hidden Routes

‎10-22-2019 08:54 AM

Hi 

 

Found out that there are "local-as 23930" configured on R1, removed it and got the hidden routes unhidden. Thanks!

 

> show route receive-protocol bgp 116.93.59.2

inet.0: 31160 destinations, 37693 routes (31160 active, 0 holddown, 0 hidden)
Restart Complete
Prefix Nexthop MED Lclpref AS path
* 116.93.45.0/24 121.127.0.206 20 110 23930 I
* 116.93.86.0/24 121.127.0.206 110 23930 I
* 116.93.99.0/24 121.127.0.206 110 23930 I
* 116.93.126.0/24 121.127.0.206 110 23930 I
* 121.127.0.0/24 121.127.0.206 110 23930 I
* 121.127.1.0/24 121.127.0.206 110 23930 I
* 203.208.24.0/24 121.127.0.206 20 110 23930 I

 

> show route receive-protocol bgp 116.93.59.2 detail table inet.0

inet.0: 31160 destinations, 37693 routes (31160 active, 0 holddown, 0 hidden)
Restart Complete
* 116.93.45.0/24 (1 entry, 1 announced)
Accepted
Nexthop: 121.127.0.206
MED: 20
Localpref: 110
AS path: 23930 I
AS path: Recorded
Communities: no-export

* 116.93.86.0/24 (1 entry, 1 announced)
Accepted
Nexthop: 121.127.0.206
Localpref: 110
AS path: 23930 I
Aggregator: 23930 121.127.1.245
AS path: Recorded
Communities: no-export

* 116.93.99.0/24 (1 entry, 1 announced)
Accepted
Nexthop: 121.127.0.206
Localpref: 110
AS path: 23930 I
Aggregator: 23930 121.127.1.245
AS path: Recorded
Communities: no-export

* 116.93.126.0/24 (1 entry, 1 announced)
Accepted
Nexthop: 121.127.0.206
Localpref: 110
AS path: 23930 I
Aggregator: 23930 121.127.1.245
AS path: Recorded
Communities: no-export

* 121.127.0.0/24 (1 entry, 1 announced)
Accepted
Nexthop: 121.127.0.206
Localpref: 110
AS path: 23930 I
Aggregator: 23930 121.127.1.240
AS path: Recorded
Communities: no-export

* 121.127.1.0/24 (1 entry, 1 announced)
Accepted
Nexthop: 121.127.0.206
Localpref: 110
AS path: 23930 I
Aggregator: 23930 121.127.1.240
AS path: Recorded
Communities: no-export

* 203.208.24.0/24 (1 entry, 1 announced)
Accepted
Nexthop: 121.127.0.206
MED: 20
Localpref: 110
AS path: 23930 I
AS path: Recorded
Communities: no-export

Highlighted
Routing

Re: iBGP Hidden Routes

[ Edited ]
‎10-22-2019 08:56 AM

Hi 

 

 

 

Highlighted
Routing

Re: iBGP Hidden Routes

‎10-22-2019 11:04 PM

Hello there,

 


saul.cabangcalan@ipc.ph wrote:

Hi 

 

 

 

 


 

Glad You found the root cause. Please mark Your fav answer as Solution so others can find it faster && benefit from it.

Thanks

Alex

 

 

_____________________________________________________________________

Please ask Your Juniper account team about Juniper Professional Services offerings.
Juniper PS can design, test & build the network/part of the network as per Your requirements

+++++++++++++++++++++++++++++++++++++++++++++

Accept as Solution = cool !
Accept as Solution+Kudo = You are a Star !
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