BGP Questions

sireesha.jasthi · ‎09-10-2009

Hello ,

I am trying to setup BGP between our primary isp and the backup isp . We have our own AS number and a netblock that we would like to advertise . I would like to setup BGP in such a way that i will be advertising a /24 bit route to the BGP cloud and the ISP will only advertise a default route to US . Also i would like to setup HSRP between the two ISP CPE routers so that the primary ISP router will have a higher standby priority and the backup isp router has a lower standby priority .I have the following two questions regarding BGP setup in this scenario :

1) Do i need to setup IBGP peeing between the primary ISP CPE and the backup ISP CPE router if i am not planning load balance between the two ISP's?

2) What is the preferred or the best way of configuring HSRP tracking ? As far as I know we could track the physical interface , line protocol , track ip route and ping an ip . I would like to know which is the preffered way of tracking HSRP .

Any help is greatly appreciated . Thank you â€¦

Giuseppe Larosa · ‎09-10-2009

Hello Sireesha,

1)

yes indeed it is quite better use local preference on the primary router.

2)

I would combine phyisical link and an IP SLA

Hope to help

Giuseppe

sireesha.jasthi · ‎09-11-2009

Thank you , so i would need to setup IBGP between the primary ISP CPE and the secondary ISP CPE eventhough both the ISP CPE routers are in the same building and same physical network ? Do you know why this is required ? I am trying to understand why an IBGP setup is required between the primary ISP CPE and the backup ISP CPE .

Giuseppe Larosa · ‎09-14-2009

Hello Sireesha,

the fact that the two routers are in the same building is meaningless.

The reason to have also the iBGP session is to have a further safety measure for some fault scenarios.

For example some faults on the client vlan side can be handled by using this iBGP session.

We can say that it is highly recommended to have this iBGP session between your routers and I would add a link between them in addition to client vlans.

Hope to help

Giuseppe