[j-nsp] Hidden IPv6 Route inside BGP - but why?
Hendrik Kahmann
hendrik.kahmann at ewetel.de
Tue Jul 21 02:14:24 EDT 2009
Hello,
all next-hops are reachable. Following excerpt describes a route which
matches our problem:
hendrik at myMachine> show route table inet6.0 2001:680::/32 extensive hidden
inet6.0: 185 destinations, 190 routes (37 active, 0 holddown, 148 hidden)
2001:680::/32 (1 entry, 0 announced)
BGP /-101
Next hop type: Indirect
Next-hop reference count: 148
Source: 2001:4110::fc1
Next hop type: Router, Next hop index: 1355
Next hop: fe80::214:f6ff:fea4:9df2 via xe-1/2/0.0, selected
Protocol next hop: 2001:4110::fc1
Indirect next hop: fa12958 1048605
State: <Hidden Int Ext>
Local AS: 9145 Peer AS: 9145
Age: 20:56:14 Metric2: 10
Task: BGP_9145.2001:4110::fc1+179
AS path: 286 I
Communities: 286:286 286:3000
Localpref: 100
Router ID: 212.6.119.5
Indirect next hops: 1
Protocol next hop: 2001:4110::fc1 Metric: 10
Indirect next hop: fa12958 1048605
Indirect path forwarding next hops: 1
Next hop type: Router
Next hop: fe80::214:f6ff:fea4:9df2 via
xe-1/2/0.0
2001:4110::fc1/128 Originating RIB: inet6.0
Metric: 10 Node path count: 1
Forwarding nexthops: 1
Nexthop: fe80::214:f6ff:fea4:9df2 via
xe-1/2/0.0
We don't have any import policies at this location. We want to use the
default-behavior of JunOS:
"Accept all BGP IPv4 routes learned from configured neighbors and import
into the inet.0 routing table. Accept all BGP IPv6 routes learned from
configured neighbors and import into the inet6.0 routing table."
At our machine pointing to the RR the route looks like the following
excerpt:
inet6.0: 421 destinations, 423 routes (181 active, 0 holddown, 240 hidden)
2001:680::/32 (1 entry, 1 announced)
TSI:
KRT in-kernel 2001:680::/32 -> {2001:7f8::11e:0:1}
Page 0 idx 0 Type 1 val 1b597b10
*BGP Preference: 170/-101
Next hop type: Router, Next hop index: 1275
Next-hop reference count: 82
Source: 2001:7f8::1a27:5051:c09d
Next hop: 2001:7f8::11e:0:1 via ge-7/1/0.0, selected
State: <Active Ext>
Local AS: 9145 Peer AS: 6695
Age: 3d 19:02:57
Task: BGP_6695.2001:7f8::1a27:5051:c09d+43654
Announcement bits (3): 0-KRT 3-BGP RT Background 4-Resolve
tree 3
AS path: 286 I
AS path: Recorded
Communities: 286:286 286:3000
Localpref: 100
Router ID: 80.81.192.157
I am looking forward to your comments.
Kind regards,
Hendrik
-----Ursprüngliche Nachricht-----
Von: Harry Reynolds [mailto:harry at juniper.net]
Gesendet: Montag, 20. Juli 2009 23:22
An: Hendrik Kahmann; juniper-nsp at puck.nether.net
Betreff: RE: [j-nsp] Hidden IPv6 Route inside BGP - but why?
I assume that the related protocol and indirect forwarding next hops are
reachable?
I'd issue a show route resolution unresolved just to be sure.
Is there any chance you have an import policy filtering that route? IIRC,
import route filters result in a hidden routes.
[edit]
regress at vpn04# run show route 2.2.2.2 table inet.0 hidden
inet.0: 36 destinations, 37 routes (34 active, 0 holddown, 2 hidden)
+ = Active Route, - = Last Active, * = Both
2.2.2.2/32 [BGP ] 00:00:07, localpref 100, from 10.255.14.181
AS path: I
> via so-1/0/0.0, label-switched-path to_r1
[edit]
regress at vpn04# show policy-options policy-statement test from {
route-filter 2.2.2.2/32 exact;
}
then reject;
regress at vpn04# show protocols bgp
traceoptions {
file bgp_r4 size 10m;
flag all detail;
}
group int {
type internal;
local-address 10.255.14.174;
import test;
family inet {
unicast;
}
family inet-vpn {
unicast;
multicast;
}
neighbor 10.255.14.181;
neighbor 10.255.14.175;
}
-----Original Message-----
From: juniper-nsp-bounces at puck.nether.net
[mailto:juniper-nsp-bounces at puck.nether.net] On Behalf Of Hendrik Kahmann
Sent: Monday, July 20, 2009 1:52 PM
To: juniper-nsp at puck.nether.net
Subject: Re: [j-nsp] Hidden IPv6 Route inside BGP - but why?
Hello,
thanks for your comment!
We are not using a RR at the edge of this scenario but the problem is
located on another location.
1. The routes are received from a RR and advertised to one of our core
systems.
2. From here the routes are propageted to our iBGP which is IPv6 enabled.
All received routes are usable at this location (at the RR).
Our other systems, which are getting the prefixes via iBGP aren't able to
install the routes into the table inet6.0 - but there is no hint like
"unusable next-hop".
Excerpt from the machine connected to the RR:
me at machine1> show route table inet6.0 2001:7b0::/32
inet6.0: 422 destinations, 424 routes (180 active, 0 holddown, 242
hidden)
+ = Active Route, - = Last Active, * = Both
2001:7b0::/32 *[BGP/170] 3d 09:34:37, MED 101, localpref 100,
from 2001:7f8::1a27:5051:c09d
AS path: 8881 I
> to 2001:7f8::22b1:192:80 via ge-7/1/0.0
Excerpt from the machine meshed in the iBGP:
me at machine2> show route table inet6.0 2001:7b0::/32 hidden
inet6.0: 184 destinations, 189 routes (37 active, 0 holddown, 147
hidden)
+ = Active Route, - = Last Active, * = Both
2001:7b0::/32 [BGP ] 11:39:05, MED 101, localpref 100, from
2001:4110::fc1
AS path: 8881 I
> to fe80::214:f6ff:fea4:9df2 via xe-1/2/0.0
Does this help us to get a step forward with this problem?
Thanks in advance,
Hendrik
Am 20.07.2009 um 16:34 schrieb Andy Wu:
> are you using RR ? make sure your RR has routes for PE's loopback
> address in inet.3 table, or inet6.3 table , ( by placing RR in LSP
> path , or create a static 0/0 route and put into inet.3 / inet6.3
> table ) , otherwise RR won't reflect the routes and all IPv6 routes
> are shown as hidden
>
>
>
>
> On Mon, Jul 20, 2009 at 10:05 AM, Hendrik Kahmann
> <hendrik.kahmann at ewetel.de
> > wrote:
>
> Hello,
>
> we have a problem with a IPv6 route in the lab, which is hidden for
> us. What could be the reason for that? In the most documents we can
> only find information around "next-hop unusable" but this does not
> seem to be the reason for us.
>
> Following excerpt has been grabbed from one of our machines:
>
>
> ME at OurMachine> show route table inet6.0 2001:4178::/32 hidden
> extensive
>
> inet6.0: 184 destinations, 189 routes (37 active, 0 holddown, 147
> hidden)
> 2001:4178::/32 (1 entry, 0 announced)
> BGP /-101
> Next hop type: Indirect
> Next-hop reference count: 147
> Source: xxxx:xxxx::xxx
> Next hop type: Router, Next hop index: 1355
> Next hop: xxxx::xxx:xxxx:xxxx:xxxx via xe-1/2/0.0,
> selected
> Protocol next hop: xxx:xxxx::fc1
> Indirect next hop: fa12958 1048605
> State: <Hidden Int Ext>
> Local AS: OurAS Peer AS: OurAS
> Age: 4:50:19 Metric2: 10
> Task: BGP_OurAS.xxx:xxxx::fc1+179
> AS path: 8767 15456 I
> Localpref: 100
> Router ID: x.x.x.x
> Indirect next hops: 1
> Protocol next hop: xxxx:xxxx::fc1 Metric: 10
> Indirect next hop: fa12958 1048605
> Indirect path forwarding next hops: 1
> Next hop type: Router
> Next hop: xxxx::xxx:xxx:xxxx:xxxx via
> xe-1/2/0.0
> xxx:xxxx::xxx/128 Originating RIB: inet6.0
> Metric: 10 Node path
> count: 1
> Forwarding nexthops: 1
> Nexthop: xxxx::xxx:xxx:xxxx:xxxx via
> xe-1/2/0.0
>
>
> Is there something pointing to a reason or a solution for this?
>
>
> Kind regards,
>
> Hendrik
>
> _______________________________________________
> juniper-nsp mailing list juniper-nsp at puck.nether.net
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