Floating Static Route

jcarrillo26

Hello All Guys and Gals,

I am new to floating static routes. I was wondering if the community would help me with my related issue i am having. I created a static route using ip route 10.10.10.0 255.255.255.0 fa4/0 250 on router A. Router A has a network with 10.10.100.1 and Router C has a network of 10.10.100.2. I need to created a floating static route between the two routers. So if they RIP routing protocol goes down 10.10.10.0 has an alternative route to get the packets. 10.10.10.0 is on Router B. At router A, add a floating static route to the 10.10.10.0 network through the 10.10.100.2 interface which is fa4/0.

Thank you for all your help i appreciate it.

pinkiaiii

use static route command on both ends ip route 0.0.0.0 0.0.0.0 ext int distance.

if doesnt work try adding extra interfaces for floating route cable-as in if one went down it would use other as static,dont forget to configure ip addresses as well.And last use show ip route, since output should be smth like this:


show ip route

Gateway of last resort is 0.0.0.0 to network 0.0.0.0 10.0.0.0/8 is variably subnetted, 3 subnets, 3 masks
R 10.0.0.0/8 [120/1] via 192.168.1.2, 00:00:10, GigabitEthernet0/0
C 10.10.10.0/24 is directly connected, GigabitEthernet0/1
L 10.10.10.1/32 is directly connected, GigabitEthernet0/1
192.168.1.0/24 is variably subnetted, 2 subnets, 2 masks
C 192.168.1.0/24 is directly connected, GigabitEthernet0/0
L 192.168.1.1/32 is directly connected, GigabitEthernet0/0
S* 0.0.0.0/0 is directly connected, GigabitEthernet0/0
Router#

in my example i used 3 routers-thus if main link goes down everything flows trough r3 on static.

jcarrillo26

Thanks for your reply i will give that a try.

networker050184

pinkiaiii wrote: »

use static route command on both ends ip route 0.0.0.0 0.0.0.0 ext int distance.

You should never do that. A static route, especially of the default kind, should have a next hop specified. What does a router do when it thinks a network is directly connected to an exit interface?

koz24

I think the correct answer is that the router will ARP whatever instead of the 1 next hop and you will be left with a gigantic ARP table. This would be a disaster on a production router.

pinkiaiii

networker050184 wrote: »

You should never do that. A static route, especially of the default kind, should have a next hop specified. What does a router do when it thinks a network is directly connected to an exit interface?

Actually using exit interface reduces timing and processor usage to figure out which ip belongs to what interface,but you are correct on using it on static,why dont remember but might be to do with what koz24 said.

networker050184

Correct what koz24 said. If you put a default route to an exit interface you are counting on the other end to support proxy arp. You're also going to fill your arp table with every external IP you hit. That can quickly eat up resources! I've seen it kill more than one router in my day.

ebohlman

That said, there are no problems with specifying an exit interface if it's on a truly point-to-point (serial or Frame Relay point-to-point) connection, since there's no need to determine an L2 address then.

networker050184

Yep won't cause an issue there, but I would never advise using a static route without a next hop.