?
Solved

recieving default routes for the internet via 2 seperate ISP's

Posted on 2011-09-07
4
Medium Priority
?
267 Views
Last Modified: 2012-05-12
Just recieved 2 internet handoffs from 2 separate ISP's and now I need to BGP peer with both.
Each handoff is connected to two seperate cisco switches which are trunked together. Each switch also has a Cisco router which will be used to peer with each ISP.  I am looking to recieve the default routes from each ISP.  I need help with the configuration of this type of setup.  I have a /24 IP block that I would like to advertise.  Can someone help me with what the config will look like if the following info is assumed?  ISP A - AS 100;  ISP B - AS 200; my registered IP block 100.100.100.0/24;  my AS 300

thanks
0
Comment
Question by:FREDARCE
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 2
  • 2
4 Comments
 
LVL 3

Accepted Solution

by:
woepwobin earned 2000 total points
ID: 36501814
This is a rough start for Router1. Assuming you got address 200.0.0.2 from ISP1, and 200.0.1.2 from ISP2 for the interconnect.

interface Ethernet1
 description LAN
 ip address 100.100.100.1 255.255.255.0
!
interface Ethernet2
 description ISP1
 ip address 200.0.0.2 255.255.255.252
!
interface Ethernet3
 description ISP2
 ip address 200.0.1.2 255.255.255.252
!
router bgp 300
 bgp log-neighbor-changes
 neighbor 100.100.100.2 remote-as 300
 neighbor 100.100.100.2 description Router2
 neighbor 100.100.100.2 prefix-list Mynet in
 neighbor 100.100.100.2 prefix-list Mynet out
 neighbor 200.0.0.1 remote-as 100
 neighbor 200.0.0.1 description ISP1
 neighbor 200.0.0.1 default-originate
 neighbor 200.0.0.1 prefix-list Mynet out
 neighbor 200.0.1.1 remote-as 200
 neighbor 200.0.1.1 description ISP2
 neighbor 200.0.1.1 default-originate
 neighbor 200.0.1.1 prefix-list Mynet out
 !
 address-family ipv4
  neighbor 100.100.100.2 activate
  neighbor 200.0.0.1 activate
  neighbor 200.0.1.1 activate
 exit-address-family
!
ip prefix-list Mynet seq 10 permit 100.100.100.0/24
ip prefix-list Mynet seq 9999 deny 0.0.0.0/0 le 32

Open in new window

0
 

Author Comment

by:FREDARCE
ID: 36506404
thanks,  can you explain the preflix-list Mynet and what it is actually doing?
0
 
LVL 3

Expert Comment

by:woepwobin
ID: 36506632
One of the purposes of the prefix list is to prevent the router from sending ISP1's routes to ISP2.

Now that I look at it again, the next lines should not be used:

neighbor 100.100.100.2 prefix-list Mynet in
neighbor 100.100.100.2 prefix-list Mynet out

Open in new window


Because you'll want Router2 to learn about Router1's default routes.
0
 

Author Comment

by:FREDARCE
ID: 36515108
is it same to say that router 2 config will be the same?  If both routers are recieving default routes then what will determine which ISP all my traffic will route through?

thanks
0

Featured Post

Efficient way to get backups off site to Azure

This user guide provides instructions on how to deploy and configure both a StoneFly Scale Out NAS Enterprise Cloud Drive virtual machine and Veeam Cloud Connect in the Microsoft Azure Cloud.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Creating an OSPF network that automatically (dynamically) reroutes network traffic over other connections to prevent network downtime.
Configuring network clients can be a chore, especially if there are a large number of them or a lot of itinerant users.  DHCP dynamically manages this process, much to the relief of users and administrators alike!
Viewers will learn how to properly install and use Secure Shell (SSH) to work on projects or homework remotely. Download Secure Shell: Follow basic installation instructions: Open Secure Shell and use "Quick Connect" to enter credentials includi…
After creating this article (http://www.experts-exchange.com/articles/23699/Setup-Mikrotik-routers-with-OSPF.html), I decided to make a video (no audio) to show you how to configure the routers and run some trace routes and pings between the 7 sites…

649 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question