Question on BGP and secondary IP's on physical interfaces

[pipsadmin]

HI,

i have a 3845 with a external interface for peering BGP with the carrier for network 216.24.238.0 which works right. This network is on a loopback because I'm doing NAT.

I also have a physical interface with IP 216.24.227.0 as primary and 216.24.228.0 as secondary.

Even with the router bgp statement with network 216.24.227.0 and 228.0, only the primary interface gets advertised. For some reason the secondary netblock 216.24.228.0 does not get propagated through BGP. This is my issue. I dont understand why the seconday IP is not getting advertised.

Is there a way around this?

Thanks

[RanilG]

Are the routing objects related to these networks registered in a public registry like RADb ?

http://www.radb.net/about.html

To me it doesn't seem so. Please check this with your service provider.

[RanilG]

If it says that your networks are advertised to the peer (sth like the following or using sh ip bgp neighbors {neighbor ip} advertised-routes)

#sh ip bgp 216.24.227.0

BGP routing table entry for 216.24.227.0/24, version 3

Paths: (1 available, best #1, table Default-IP-Routing-Table)

Advertised to non peer-group peers:

216.24.228.1

then I suppose it would be better to double check this with your transit provider(carrier)

[Giuseppe Larosa]

Hello Nelson,

these subnets are registered to different AS numbers

see below

> 216.24.227.0 0.0.0.0 0 32768 i

*> 216.24.228.0 0.0.0.0 0 32768 i

*> 216.24.238.0 0.0.0.0 0 32768 i

here are the results from etabeta.seabone.net a european public looking glass

216.24.227.0/24 AS path : 1239 701 belongs to AS 701

216.24.228.0/24 AS path : 1239 701 belongs to AS 701

216.24.238.0/24 AS path : 1239 701 17358 belongs to AS 17358

AS 701 is UUNET now Verizon = MCI your provider

from http://www.arin.net

OrgName: eToll, Inc.

OrgID: ETOLLI

Address: 1260 University St.

Address: 5th Floor

City: Montreal

StateProv: QC

PostalCode: H3B-3B9

Country: CA

ASNumber: 17358

ASName: ETOLL1

ASHandle: AS17358

Comment:

If your routers are in AS 17358 it is correct that only 216.24.238.0/24 is seen on the internet.

The other two prefixes are registered to AS701 and cannot be seen in the internet as originated in AS 17358 this would be wrong.

A public IP Prefix belongs to only one AS number.

Check with your provider:

or you stay with the static routes or they change the registration so that these prefixes are with AS 17358 and you can advertise them

Secondary ip addresses are not the issue here.

Hope to help

Giuseppe

[RanilG]

This will give you a better overview of networks announced by AS17358.

http://www.cidr-report.org/cgi-bin/as-report?as=17358&view=2.0&v=4

HTH

P.S. Many thanks to Tony Bates, Philip Smith, & Geoff Huston

[Giuseppe Larosa]

Hello Ranil,

you have been the first to understand this issue

the subnets are not registered with AS17358

Best Regards

Giuseppe

[RanilG]

Hi,

It seems to be working now, Doesn't it?

http://www.cidr-report.org/cgi-bin/as-report?as=AS17358&v=4&view=2.0