Go Premium for a chance to win a PS4. Enter to Win

x
?
Solved

gateway metric cost

Posted on 2009-05-18
4
Medium Priority
?
589 Views
Last Modified: 2012-05-07
quick explanation of the situation.
2003 server 1 Nic.
2 internet feeds
what i want to do is have the server attempt network traffic over the first feed and if it is unable to reach the destination then it will try across the 2nd feed.
My thinking on this is that if i add two gateways to the NIC with a lower metric on the first then that should work as per http://wiki.answers.com/Q/What_is_Gateway_and_Metric and http://support.microsoft.com/kb/299540

My understanding is that the metric is basically a cost on the connection, so do i simply set them as 1 and 2 or do i need to set them as say 1 and 10000 as i am not sure if the cost is simply added to the total cost of the route.

Eg if browse to google
gateway 1
  cost of metric = 1
  cost of route = 50
  Total cost = 51

Gateway 2
  cost of metric = 2
  cost of route = 30
  Total cost = 32

So in this instance as gateway 2 can get to the site quicker it will have a lower total cost and therefore will allways get used in preferance to gateway 1. But if i set the gateway 2 metric to 1000 then the total cost on the route for gateway2 would be 1030 which is higher.

Can anyone shed some light on this for me.
0
Comment
Question by:Andrew Davis
4 Comments
 
LVL 13

Expert Comment

by:Quori
ID: 24418210
In 2003 you can use automatic metric, but that may do strange things.

Metric only comes into effect when you have two routes to the same location. So in your gateway, or default route, scenario you'd have two entries to network 0.0.0.0 mask 0.0.0.0 via the same interface but different 'next hop' or gateway so the metric you set doesn't really matter, can be 100/200 or 1/2 but to keep it safe you may want to use values above 20.

Further more, an issue you have here is that the 2k3 box will only swap the route if the next-hop goes down, which is unlikely if it is a router. You're better off doing path selection on a router level, or if you really must use the 2k3 box use one of the dynamic routing protocols that 2k3 supports - providing your routers support said protocol also.
0
 
LVL 19

Author Comment

by:Andrew Davis
ID: 24419071
thats all fine. the issue that i have is that i have a VOIP service on one subnet with its own router, and then an existing data network, and the data network needs to see the voip network and i cannot adjust either router, so the simple answer was to put the server onto the voip network via a second ip on the nic and then create a second connection to the voip router (for access to remote VPN handsets). the same time try to keep the data network off of the voip cloud.
0
 
LVL 10

Accepted Solution

by:
lanboyo earned 1500 total points
ID: 24420499
You can tweak which interface is used in a multi nic situation by pointing the routes at an interface. Like almost any routing device, windows boxes will go to the more specific route before a less specific route. So if you have a route to the remote handset subnet pointing at the gateway on nic 2, it will use this in preference to a static route pointing to nic 1.

If the interface drops, it will use the less specific route. Of course in a dual nic windows box this is changing what th ip of the host appears to be..
0
 
LVL 71

Expert Comment

by:Qlemo
ID: 24420684
That's more easily done with a specific route on the VoIP network.

NIC1 - data network:
  • default gateway set to the data network router
  • normal network and host routes for the data network internal IP addresses with NIC1 as gateway
NIC2 - VoIP network:
  • No default gateway (!)
  • normal network and host routes for the VoIP network internal IP addresses with NIC2 as gateway
  • optional network routes for remote VoIP addresses, using VoIP gateway.
0

Featured Post

Free Tool: Subnet Calculator

The subnet calculator helps you design networks by taking an IP address and network mask and returning information such as network, broadcast address, and host range.

One of a set of tools we're offering as a way of saying thank you for being a part of the community.

Question has a verified solution.

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

This article is in regards to the Cisco QSFP-4SFP10G-CU1M cables, which are designed to uplink/downlink 40GB ports to 10GB SFP ports. I recently experienced this and found very little configuration documentation on how these are supposed to be confi…
In this article, the configuration steps in Zabbix to monitor devices via SNMP will be discussed with some real examples on Cisco Router/Switch, Catalyst Switch, NAS Synology device.
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…
There's a multitude of different network monitoring solutions out there, and you're probably wondering what makes NetCrunch so special. It's completely agentless, but does let you create an agent, if you desire. It offers powerful scalability …

926 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