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BGP - seperating own routes


we are going to be peering with an ISP, and they want us to take the Full BGP internet routing table,

I am going to be using two Cat6500 for this that also server other puroposes in routing in my private networks,

what is the best way to keep the bgp routes seperate from my own routes, f.e. should I run VRF lite to and put all my routes into an VRF and then have the internet routing table as the global table,

or what is generaly done in situationes like this ?




Re: BGP - seperating own routes

You can do the vrf-lite but then you would need to have a connection between Internet and your internal network.

If not using vrf-lite, you can use route-leaked vrf: point your vrf default route to global table.

You can also keep your internal routes in the same global table and have filters to limit what you advertise/receive.

Hope this helps.

Re: BGP - seperating own routes


in principle it would be enough NOT to configure redistribution between BGP and IGP (which is never the best idea). IP routing protocols are like "ships in the night" - they don´t see each otherunless you configure redistribution.

In addition I would apply the proper inbound and outbound filters to be sure an ISP failure/error will not get you in trouble. An example configuration could look like this:

interface Ethernet0/1

description to ISP

ip address

router bgp 65000

network mask

neighbor remote-as 1 !replace with ISP AS

neighbor prefix-list NoTrash in

neighbor filter-list 1 out

neighbor maximum-prefix 300000

no auto-summary

ip as-path access-list 1 permit ^$

ip prefix-list NoTrash deny le 32

ip prefix-list NoTrash deny le 32

ip prefix-list NoTrash deny le 32

ip prefix-list NoTrash deny le 32

ip prefix-list NoTrash permit le 24

ip route Null 0 250

This assumes you want to announce to the ISP as your official IP addresses. You need of course to adjust interfaces, IP addresses ans AS numbers.

Hope this helps! PLease rate all posts.

Regards, Martin

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