Dual Gateway (OSPF, NAT and Transparent web proxy)

RouterOS General
1

hi guys,

how is it possible to choose the shortest path within two ISP link and while doing NAT and Transparent Web-proxy?

as far as I know it must be related to OSPF.

thanks

2

OSPF is usually not useful in finding the shortest path to any destination on the internet
beyond your autonomous system (AS). That’s because OSPF is an IGP.

To determine the shortest (not necessarily with the best performance!) path through your
uplink ISPs you’d use BGP.

Use OSPF to tell everything inside your AS the shortest (best)
path to your internet gateway(s), and use BGP on the gateway(s).

It usually makes no sense to export EBGP routes into OSPF.


–Tom

3

I will have better understanding if you point some article explaining bgp.

the purpose of this question is that i have a two different ISP which one have better performance over internation sites and the other for local sites which may even have viceversa effect on certain sites.

So I want it dynamically choose each link for opening each separate sockets.

from my understanding using ECMP (simply adding two gateways to a mt box) will cause a network conflict (bad performance over long sequence of downloading) or even stopping my transparent web-proxy for unknown reason (probably bad setup in my firewall)

any idea of how exactly implement it?

thanks

4

For BGP, I’d recommend that you read the book “Internet Routing Architectures”
by Sam Halabi, ISBN 157870233X. It’s one of the standard books on the subject,
but everything is explained in terms of Cisco configuration. Anyway, it describes
the concepts very well.

Once you have read that book, then revisit the BGP section of the RouterOS manual
and you should be ready to go.

–Tom