INTELLIGENT WORK FORUMS
FOR COMPUTER PROFESSIONALS

Log In

Come Join Us!

Are you a
Computer / IT professional?
Join Tek-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Tek-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Jobs

Standard IP routing

Standard IP routing

(OP)
Hi Guys, just a simple question going to the standards of IP routing :

If a router has 2 networks connected to 2 different WAN ports

What will the router decide when he has 2 default gateways configured in his routing table (without the use of any advanced routing protocol, just standard static routing), each pointing to one of the WAN networks

will he :
- switch between these 2 gateways (and perform a sort of loadsharing/balancing), so forwarding each packet to a different gateway
or
- will he forward the packets to the first entry he finds in his routing table ? and always using the same gateway.

Regards

J.

RE: Standard IP routing

The RV042 dual WAN router can do fail over or weighted load balancing. You can also pin certain ports to one WAN or the other.  If you pin 443 to one WAN, your SSL connections all use that WAN, etc.
Other Dual WAN routers I have used have even more options. My defunct Webramp allowed you to make additional WAN connections as load increased. (it used 3 56k modems, before broadband)

I tried to remain child-like, all I acheived was childish.

RE: Standard IP routing

(OP)
Hi Jim, thanks for your reply (checked the proposed router). But in fact my question was just about TCP/IP routing standards without any hardware/software aid : what will a routing process do when it sees that it has 2 default gateways in it's routing table (tried to look it up via an RFC, but could not find it)

I think it will just forward the packet to the first entry it encounters in the routing table, and will (as a standard) never use the second entry. This because the program will jump out of the tabel as soon as it encounters the first hit.

But i'm not sure about this. Hope someone can give me the correct information ?
 

RE: Standard IP routing

I would say it depends on the OS.
 
UNIX people have told me in the past that in the situation you describe, the two default routes will be used alternately. I'm sure I've played with it on Cisco and other gear but I have no recollection about how it acually behaves.
 
One thing to remember is that it's not correct to say that the routing table is read as you describe (in the same way as an access list), because the actual routing isn't done by the routing table. The routing table is just where routes are configured (manually or using routing protocols). Actual routing of packets is no longer done by referring to the routing table.

RE: Standard IP routing

(OP)
Hi Vince, Thanks for your reply. You don't know about any RFC that is describing the routing process ?

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Tek-Tips Forums free from inappropriate posts.
The Tek-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Tek-Tips forums is a member-only feature.

Click Here to join Tek-Tips and talk with other members!

Resources

Close Box

Join Tek-Tips® Today!

Join your peers on the Internet's largest technical computer professional community.
It's easy to join and it's free.

Here's Why Members Love Tek-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close