Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
New Member

Questions about BGP and OSPF: Default-information originate always

Hi guys,

He have some questions about BGP and OSPF: Default-information originate always

I have this scenarious:

:

isp-ospf-default.png

To annunciate the default rote to my network I use default-information originate always in boths routers: RTR A and RTR B ( ospf process ).

What is the better pratic to use default network in this scenario ? I don´t redistribute Ospf into BGP

In corporate network a router received the 2 default networks but with the same metric and I noticied looping when I send packets from corporate network to Internet. I would like to use 2 default network for load balance and reability

Can you help me ?

Thank you

Everyone's tags (4)
2 REPLIES

Questions about BGP and OSPF: Default-information originate alwa

My assuption is that your ISP's are providing a default route? Load balancing may not be a good idea with two different IPS's. It may lead to out-of-sequence traffic, all kinds of NAT issues and bad performance in general.

Better option is to advertise the default routes with different metrics. When one router fails, the other will take over the load. If you have a default route via BGP, you can make the advertisement conditional, i.e. not using the keyword "always".

Obviously this will not work when you run a full BGP table but in that case, load balancing will be automatically introduced because the bgp peers will decide who of them has the best route. Even then you need to take into account that you need to have symmetric routing in order for NAT to work.

regards,

Leo

Questions about BGP and OSPF: Default-information originate alwa

i agree 100% with leo post load balancing is a problem

also using the always keyword is not recommended in your case above because this will blackhole the traffic going to the Internet in the case of on ISP link is down while ospf will continue advertise the default route to the internal network

HTH

1704
Views
0
Helpful
2
Replies
CreatePlease to create content