11-21-2015 05:02 AM - edited 03-05-2019 02:47 AM
Can someone please assist me with this issue?
I have an internet edge router and do not want to receive the full BGP table from the internet.
What is the best way to go? e.g best practices.
my next hop is my ISP using a /30 ip address
Thank you
11-21-2015 06:30 AM
Hello,
Are you an ISP or an end user. If you are only an end user, you can ask your ISP to send you a default route.
Masoud
11-21-2015 10:01 AM
I am an end user
Thank you
11-21-2015 10:18 AM
Receiving a default route is suggested if you are an end user. In this way, you do not have to deal with so many routes which consume memory and need administration. ISPs are usually willing to send you a default route as opposed to full internet routes. You might implement filtering as others suggested to prevent adding wrong routes to the routing table in case of misconfiguration. Having another link to another ISP is also recommented in order to avoid single link failure.
Masoud
11-22-2015 05:17 AM
Thank you very much Masoud
11-22-2015 06:59 AM
You are very welcome. Have a good Thanksgiving.
Masoud
11-22-2015 01:29 AM
Hello
Below would a very basic example of an bgp peering to an Isp
With in/outbound filtering.obviously you can amend to this to suit your needs
Ip as-path access-list permit ^$
ip prefix-list default permit 0.0.0.0/0
Router bgp xx
no auto-summary
no synchroniszation
Neighbor x.x.x.x remote-as ISP (peer to ISP)
Neighbor x.x.x.x password xxxx ( basic authentication)
Neighbour x.x.x.x prefix-list default in ( accept default only)
Neigbour x.x.x.x filter-list 10 out ( advertise only local routes)
res
paul
11-22-2015 05:16 AM
Thank you very much Paul!
I really appreciate the response!
11-21-2015 06:32 AM
You can do couple of things in this case:
- You can ask your ISP to not send the whole Internet Routing table but a default route for Internet connectivity.
- if that is not possible, then you can perform route filtering on your router permitting only those prefixes that you need in your network.
Hope this helps
Regards
Vinit
11-21-2015 07:17 AM
Hi,
I'd rephrase:
...
- if that is not possible, then you can perform route filtering on your router denying all prefixes received from the ISP and configure a static default route on your router pointing to your ISP router IP address as the next-hop.
BR,
Milan
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