eigrp cost calculation

[tirthasarathi.datta]

sir,

i have a 2 no of router which is connected with back to back. Bandwidth of one serial is 512 Kbps and another is 2048, eigrp rouiting protocol is running between two router. i want to know, when eigrp calculate cost which bandwidth it will take and why?

and requesting u to provide me some link related with this type of scenario

Thanks

tirthasarathi

[Jon Marshall]

tirthasarathi.datta wrote:
sir,
i have a 2 no of router which is connected with back to back. Bandwidth of one serial is 512 Kbps and another is 2048, eigrp rouiting protocol is running between two router. i want to know, when eigrp calculate cost which bandwidth it will take and why?
and requesting u to provide me some link related with this type of scenario
Thanks
tirthasarathi

EIGRP uses bandwidth and delay by default although it can use another 3 metrics as well. Note Cisco recommned not to use the other 3 metrics.

The simple answer to your question is it will use the 2048 link providing you have configured the bandwidth correctly under the interface. See this link for a full explanation -

EIGRP metrics

Jon

[tirthasarathi.datta]

Thanks for reply. Whatever u say thats i know. But my question was different. In that scenarion only, which bandwidth eigrp use for bandwidth calculation.

Router A ( 64 K)

Gateway of last resort is not set

     10.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
D       10.0.0.0/8 is a summary, 00:04:13, Null0
C       10.0.0.0/30 is directly connected, Serial0/0/0
C    192.168.20.0/24 is directly connected, Loopback0
D    192.168.30.0/24 [90/40640000] via 10.0.0.2, 00:04:10, Serial0/0/0

Router B (2048 K)

Gateway of last resort is not set

     10.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
D       10.0.0.0/8 is a summary, 00:01:18, Null0
C       10.0.0.0/30 is directly connected, Serial0/0/0
D    192.168.20.0/24 [90/1889792] via 10.0.0.1, 00:01:14, Serial0/0/0
C    192.168.30.0/24 is directly connected, Loopback0

(delay is same in both router)

Thanks

tirthasarathi

[Jon Marshall]

Not sure what you mean.

Router A will use the 64K bandwidth value in it's calculations to get to networks on B and B will use 2048K in it's calcluations to get to A. EIGRP uses the minimum bandwidth configured on the path to a destination network. As you only have 2 routers A will use it's bandwidth value to get to B and B will use it's bandwidth value to get to A.

Jon

[tirthasarathi.datta]

thanks

tirtha