06-23-2013 11:57 AM - edited 03-04-2019 08:17 PM
If can anyone help
when i issue command "sh ip bgp" it shows
* i 0.0.0.0 a.b.c.d 0 90 0 ASN i
* a.b.c.d 0 90 0 ASN i
*> a.b.c.d 100 0ASN i
0.0.0.0 0 i <<----------------
* 1.0.0.0/24 a.b.c.d 90 0 5483 15169 i
* a.b.c.d 90 0 5483 15169 i
*> a.b.c.d 90 0 8400 15169 i
Refresh Epoch 1
Local, (default-originate)
0.0.0.0 from 0.0.0.0 (aa.bb.cc.dd) <-- aa.bb.cc.dd is loopback ip on same router
Origin IGP, localpref 100, external
Can anyone help , why is this .
06-23-2013 01:30 PM
hi,
I think you are orginating a default route (0.0.0.0) within your BGP configuraton. please confirm you have the following command within bgp configuration;
- default-information originate
06-23-2013 02:01 PM
No i dont have that .
I mean i have , but only to bgp customers .
like :
neighbor aaa.bbb.ccc.ddd default-originate
aaa.bbb.ccc.ddd is ip of customer router
06-23-2013 03:36 PM
Hello,
even though it appears in the BGP table, it's not going to be a candidate to the RIB table. I have seen in previous IOS versions that, when this command is applied (neighbor x.y.z.x default-originate) the result is that the peer is advertising a default route dynamically regardless if it has a default route in the RIB or not. Also, it does not install a default in the BGP table and it bypasses the BGP filters (Adj-Rib-Out). I have tested in IOS 15.0M and I have got the same results that you have posted. I have tested the behavior of this and it appears to me just a "cosmetic" thing in the router:
R1 is advertising a default route to R2
R1#show ip bgp
BGP table version is 2, local router ID is 10.1.12.1
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
0.0.0.0 0.0.0.0 0 i
However, it does not appear in the RIB:
R1#show ip route 0.0.0.0
% Network not in table
I have installed another default route as a matter of fact that the previous one is not taken into account:
ip route 0.0.0.0 0.0.0.0 Null0
!
Router bgp 1
network 0.0.0.0 route-map TEST
The route-map TEST sets the weight to 0 and Local Preference to 0 to become worse than the other:
route-map TEST permit 10
set local-preference 0
set weight 0
But, as you can see, it is the best as the other one is not eligible:
R1#sh ip bgp 0.0.0.0
BGP routing table entry for 0.0.0.0/0, version 10
Paths: (2 available, best #1, table default)
Advertised to update-groups:
1
Local
0.0.0.0 from 0.0.0.0 (10.1.12.1)
Origin IGP, metric 0, localpref 0, valid, sourced, local, best
Local, (default-originate)
0.0.0.0 from 0.0.0.0 (10.1.12.1)
Origin IGP, localpref 100, external
Best Regards,
Jose
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