IP ROUTING

[fmugambi]

Hello guys, below is my topology,

I have added internet fw  and introduced ISP on site B.

Before site B resources/ servers would go via mpls to site a to access internet.

I introduced the above to make each site use its own isp respectively.

I ran to challenges, site b resources were not able to get to their isp/internet, until i introduced " ip route 0.0.0.0/0 sitebinternetfw interface. --> which works but causes some issues.

is there a way, to manipulate just internet traffic for site b resources without introducing static entries? and not affecting site a and b from communicating with each other?

[MHM Cisco World · Accepted solution]

Filter we have in your case

1- redis staitc into ospf using route-map

2- redis ospf into bgp using

A- route-map

B- using match and specify in or ex1 or ex2 or mix

3- using bgp route-map OUT

These three filter can be use in your case. 

MHM

[fmugambi]

thank you alot, i implemented this on production network, site b now knows site a static routes and vice-versa.

[MHM Cisco World]

You are so welcome 

have a nice summer 

MHM

[fmugambi]

or since permit is 10, and deny is 1000, then 10 takes the day?

[paul driver]

Hello

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@fmugambi wrote:
now when i want to introduce isp specific access to each site, the easiet way i went about it was, introducing the 0.0.0.0/0 to ciscoasa fw on site b.--> site b resources now get their internet access via their site b isp. my problem comes, when vpn

1. how to sort vpn learnt static routes be advertised to site b without introducing static routes at 1941 site mpls edge router?
2. is it possible as the setup is, make site b resources uses site b isp, without introducing default route at site be core sw?

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The assumption is both sites are in their own ASN ?

If so, the fw and the 1941 rtr at each site needs to know of each other via bgp so suggest to remove these static routes you have introduced, Create an IBGP peering between each sites bgp rtr and its own FW, advertise a default from each fw into bgp and redistribute that into ospf type 1 with low seed metric.
By default the external traffic should route via its own ISP  and s2s traffic will traverse over the the s2s bgp peering.

Upon failure of any sites ISP, lan traffic from that site will re-route over the s2s bgp peering for external connectivity